Gonçal Cerdà-Beneito
email: goncal.cerda-beneito@enpc.fr

Sandrine Wenglenski

Claire Hancock

Towards an understanding of single mothers' urban mobility. A comparative analysis of parents' travel patterns in the Paris region

Keywords: Daily mobility, family constraints, household travel survey, single mothers, Paris region

INTRODUCTION

A body of work documents the constant growth of one-parent households in urban areas [START_REF] Chardon | Les familles monoparentales[END_REF][START_REF] Drieux | Familles monoparentales franciliennes : les femmes toujours en première ligne face aux difficultés[END_REF]. In the Paris region, the latest population data indicates that 23.5% of households with children under the age of 18 are headed by a single parent (3), 84.15% of which are single-mothers. These mothers face specific concerns due to their status. They are twice as affected by poverty as mother in dualparent households [START_REF] Drieux | Familles monoparentales franciliennes : les femmes toujours en première ligne face aux difficultés[END_REF]. From a daily life perspective, many studies have demonstrated that single mothers struggle to juggle family and professional activities [START_REF] Torrado | Mujeres al frente de familias monoparentales[END_REF]. They must draw a salary to maintain the household and carry out domestic work, without the help of a partner.

Parents -and people in general-activities program is constrained by social rhythms, such as work or school schedules [START_REF] De Coninck | Les mobilités des actifs : les raisons du quotidien[END_REF]. Many of the daily activities require travel to link different spaces: each trip is made to carry out an activity in a specific time and place. That is why authors claim daily mobility is a space-time indicator of daily activities [START_REF] Hägerstraand | What about people in regional science?[END_REF]. Single mothers being a growing category of people with particular concerns, I will analyze how mobility reveal specificities and constraints of these mothers' daily life in the Paris region. The number of trips per purpose or the time spent traveling could be indicators of everyday life's efforts and possibilities [START_REF] Scholten | Re-Reading Time-Geography from a Gender Perspective: Examples from Gendered mobility[END_REF].

In dual-parent households, mothers spend twice as much time as fathers doing domestic chores [START_REF] Roy | Le travail domestique : 60 milliards d'heures en 2010[END_REF], and the latter have higher rates of employment and full-time activity [START_REF] Pailhé | Concilier, organiser, renoncer : quel genre d'arrangements ?[END_REF]. Hypothetically these "gender gaps" should disappear among single parents because they do not have a partner with whom to "share" domestic work, and most are employed. However single mothers spend more time in domestic work than single fathers [START_REF] Roy | Le travail domestique : 60 milliards d'heures en 2010[END_REF], and the proportion of single fathers with full-time paid employment is 16.7% higher than that of single mothers (3). It is therefore interesting to compare the mobility patterns of single mothers and those of single parents, and also with those of parents who are in a relationship.

Even if most of the research about parents' daily mobility considers them as an aggregate or study only dual-parent households, other researchers have already focused on the specificity of single parents. In 1989, several papers concluded that one-parent households have significantly different travel patterns from dual-parent households [START_REF] Rosenbloom | The transportation needs of single salaried mothers: a critical analysis[END_REF], and found that single mothers' mobility is impacted by all the responsibilities they shoulder: they make more trips, trip-link more often, travel further than comparable married women and are more constrained by their children than married parents of either sex [START_REF] Kostyniuk | Mobility of single parents: what do the trip records show?[END_REF][START_REF] Rutherford | Single parents in the suburbs: journey-to-work and access to transportation[END_REF]. Even if this work shows the importance of family charges, it mostly uses data on commuting, leaving aside other "domestic" purposes. However, using the US National Household Transport Survey, Rosenbloom explained that single mothers made a high percentage of trips to serve passengers and for shopping, especially mothers with children under the age of 6 [START_REF] Rosenbloom | Understanding Women's and Men's Travel Patterns: The Research Challenge[END_REF].

The most recent work about single parents and transportation is presented in a context of "social exclusion" [START_REF] Farber | A time-use investigation of shopping participation in three Canadian cities: is there evidence of social exclusion?[END_REF][START_REF] Lucas | Transport and social exclusion: Where are we now?[END_REF]. Some shown the importance of transport facilities to ensure accessibility and avoid exclusion [START_REF] Wang | Is Transit Important for Single Parents? Evidence from Maryland[END_REF]. Others found that these parents have a more constrained activity program than other parents, particularly in low-income households [START_REF] Farber | A time-use investigation of shopping participation in three Canadian cities: is there evidence of social exclusion?[END_REF]. This literature introduced the term of "social exclusion", using daily mobility as a possible indicator of social inequalities. However, none adopts a gendered perspective, i.e. a theoretical reflection about mobility and "gender inequalities". This paper is based on the first results of an ongoing PhD research in which I seek to understand the role of mobility in gender inequalities between parents, combining qualitative (semi-directive interviews) and quantitative methods. Here I explore parents' travel patterns to understand the specificities of single mothers' daily life. I use a mobility survey of the Paris region, where single parents' mobility has not been studied, and where little research focuses on gender differences in mobility [START_REF] Coutras | Femmes et transports en milieu urbain[END_REF][START_REF] Prédali | La mobilité comme révélateur de l'évolution des modes de vies des femmes : les tendances des pratiques des femmes en milieu de vie en Ile-de-France depuis les années[END_REF][START_REF] Motte-Baumvol | Différences de genre et formes de dépendances des conjoints biactifs dans l'accompagnement des enfants[END_REF].

METHODOLOGY

The Paris region is one of the most populated urban regions in Europe: 12 million inhabitants live in an area of 12,012 km². The population distribution and density is divergent, with a dense and populated center, large but less populated suburbs, and rural outskirts. The Paris region has a welldeveloped transit network with a metro in the inner city and the nearest outskirts, a suburban rail system, and large bus network. This quantitative research is based on data from the Enquête Globale Transport 2010 (EGT-2010), the latest Parisian household travel survey, conducted by the regional mobility service. EGT-2010 contains information about the household (housing, place of residence, incomes and transport equipment) and about all its members (age, sex, occupation information and the possession transport facilities as driving license). It includes, for each person aged 5 years and over, detailed information about all the trips of the day before the survey (purpose, duration, hours and transport mode). The results comprise information for 35,175 individuals and 124,262 trips. EGT-2010 does not contain explicit information about the household structure and the presence of children. However, for each individual there is information about the relationship (descendant, partner, ascendant, other) with the household head. That allows me to identify the parents and define two categories: single/living with a partner. This research is limited to the parents of children under 18, which in France is the age of legal majority and the age required for a driving license. I exclude a minority of complex households with children. My sample contains 42,733 trips and 9,303 individuals. The sample of single fathers is minute -165 individuals and 802 tripsdue to their small number, the data are to be handled carefully.

Data analysis was conducted with descriptive statistics, mainly using central tendencies -meanand cross tabulations. To answer my research questions, I use data about the purpose of the trip, which I cross-referenced with sex and the fact of living with a partner. I focused on the purposes that constrain parents' daily life: professional and care activities. The latter is not a predefined category in the survey; I have created it grouping shopping, drop off/pick up and other care trips (administrative tasks, take care of someone, parents meetings…) [START_REF] Sánchez De Madariaga | Mobility of Care: Introducing New Concepts in Urban Transport[END_REF].

FINDINGS

Mobility patterns differences between mothers and fathers

In the Paris region, almost all the parents, with a weak difference between sexes and family status, made at least a trip the day before the survey. They had at least one out-of-home activity. However, the results differ among parents' groups if trip purposes are considered. Indeed, the various indicators show uniform results for parents in dual-parent households (Table 1, Figure 1). Regarding gender differences, as expected, results reveal higher involvement of mothers in care activities -56% of their trips versus 38% for fathers-; and higher involvement of fathers in professional paid activities -43% of their trips versus 26% for mothers. These results are related to employment and full-time activity rates, which present similar differences. In the case of one-parent families, the gender disparities are narrower (Figure 2). The difference in the mean of care trips is small: average single fathers made 1.41 trips and average single mothers 1.60. In fact, the percentage of single fathers' shopping trips is slightly higher than for single mothers. Mobility indicators for single parents are between those of mothers and fathers living with a partner. Single mothers made more professional trips and less care trips, and single fathers travelled more for care activities and less for professional reasons compared with their dual-parent household counterparts. The differences between sexes persist among single parents. Even if single mothers are almost as likely as mothers in couple to travel for care purposes, they are more likely to make trips with a work purpose.

FIGURE 1. Parents' in couple trips per purpose FIGURE 2. Single parents' trips per purpose

Use of time and time of the activities

A time-use approach can prove useful for a deeper understanding single mothers' daily mobility, compared to other parents. This approach is used in research that has examined the gender gap in domestic and care work using the Use of Time Surveys [START_REF] Roy | Le travail domestique : 60 milliards d'heures en 2010[END_REF]. With the EGT-2010 data, it is possible to calculate the travel time-budgets (TTB), which give the time spent on the trip between two places. The average results of the TTB (Table 2) confirm what has been observed with the previous indicators. Furthermore, they show that, despite the tightening of mobility patterns among singleparents, two gendered tendencies persist. On the one hand, all mothers, single or not, spend almost the same amount of time on travelling for care activities as they do on professional trips. On the other hand, whether single or in couple, fathers spend more time on professional trips than on care activities ones -27 minutes more for fathers in couple, and 14 minutes more for single fathers. In all cases, the TTB for paid professional activities is higher than that for care, because often trips to the workplace are longer -in time and space-and the domestic tasks out-of-home are done in the surroundings of the home. Overall, these differences are almost imperceptible for mothers. In addition, TTB results show mobility "specializations" among parents' groups. Fathers in couple have the biggest TTB: 27 minutes more than mothers in couple, 7 minutes more than single mothers and 2 minutes more than single fathers. They are also the ones who spend the most time on professional trips: almost 8 minutes more than single fathers and 40 minutes more than mothers in couple. Single mothers are the ones who spend most time in the care trips: 4 minutes more than mothers in couple and single fathers, and 10 minutes more than fathers in couple. This could be a sign of single mothers' daily complexity related to domestic and familiar constraints. I chose to focus on drop off/pick up trips, which are the main "domestic purpose" among parents and have given clear results in previous research [START_REF] Motte-Baumvol | Différences de genre et formes de dépendances des conjoints biactifs dans l'accompagnement des enfants[END_REF]. At almost all times, and particularly at peak hours -school beginning and end, and lunchtime-mothers in couple did a proportionally higher number of drop off/pick up trips. The differences among single mothers and fathers are less clear than for the other parents. However, single mothers did proportionally more drop off/pick up trips than fathers in the school beginning and end time. It is also interesting to note the differences between mothers. While the trips of the mothers living with a partner were more frequent in the peak hours, single mothers' were more dispersed, particularly in the evening. That could be due to the fact that single mothers leave children at school later, in "leisure activities" programs.

CONCLUSIONS

Exploitation of the latest household travel survey of the Paris region confirms relevant gender differences among parents living with a partner, revealing an unequal share of domestic work. The disparities are narrower among single parents. However, results corroborate what has been previously observed in other contexts (13): single mothers have specific travel patterns. They travel more than fathers for care activities. Furthermore, their TTB for these activities is the highest among the categories of parents. Even if the percentage of full time paid work is similar for single mothers and mothers with a partner, the former travel more for work and spend more time on professional trips. Single mothers' daily life is conditioned by family constraints and professional activities, which tends to complicate their mobility patterns.

There are however, many limitations in the analysis for the understanding of single mothers' daily life and the role mobility plays. I have only considered sex and conjugal status, but previous research asserts that "low income single mothers, and those from ethnic minorities, may face additional problems" [START_REF] Rosenbloom | Understanding Women's and Men's Travel Patterns: The Research Challenge[END_REF]. It could be also interesting to explore the influence of children's age and number. Furthermore, even if I concentrated on an urban area, I have not explored possible differences between parents living in the dense center areas and parents living on the outskirts, as shown previously for other groups [START_REF] Farber | A time-use investigation of shopping participation in three Canadian cities: is there evidence of social exclusion?[END_REF].

Other limitations are related to the survey and quantitative methods. I could not analyze the way single parents manage their daily life and their mobility decisions. How do single mothers handle various tasks? Do they see travel time as a constraint? If single fathers are in the same family situation, why do they have fewer drop off/pick up trips? Are they receiving help from others (friend or family)? On the next steps of my PhD research, I will try to answer these questions using qualitative methods.

FIGURE 3 .

 3 FIGURE 3. Parents' drop off/pick up trips by hour

TABLE 1 . Trips of parents per purpose

 1

	Purpose	Drop off /pick up	Shopping	Care activities	Professional
	Indicator	%* Mean**	%*	Mean**	%*	Mean**	%*	Mean**
	Mothers in couple 54.78	1.15 53.65	0.48 70.00	1.73 52.33	0.82
	Fathers in couple	40.96	0.69 46.35	0.34 56.61	1.13 73.42	1.31
	Single Mothers	46.49	0.95 34.36	0.45 69.41	1.60 59.71	0.96
	Single Fathers	45.49	0.82 36.46	0.48 68.51	1.41 72.11	1.21
	Source: EGT 2010-STIF-OMNIL-DRIEA, Gonçal Cerdà Beneito.

* Percentage of parents who have made at least a trip for the purpose the day before the survey. ** Average number of trips per purpose.

TABLE 2 . Average daily travel time-budget per purpose (minutes)

 2

	Purpose	Drop off/pick up	Shopping	Care activities	Professional	All
	Mothers in couple	14′23″	7′28″	23′53″	24′28″	94′08″
	Fathers in couple	10′00″	5′37″	17′41″	44′41″	120′59″
	Single mothers	14′55″	7′32″	28′10″	28′45″	113′49″
	Single fathers	14′19″	6′33″	23′26″	37′06″	118′53″
	Source: EGT 2010-STIF-OMNIL-DRIEA, Gonçal Cerdà Beneito.


Pridgeon R M Bateman

M W Chase

Chromosome numbers and metaphase plates are given for

1928. Dactylorhiza maculata (L.) Soó -2n = 40 (Fig. 1c).

BH: Katranica, Muške Vode, Kladanj, serpentine, 44° 14' 11,64'' N, 18° 34' 17,87'' E, 825 m a.s.l., 06 May 2008, private herbarium of F.P.

Dactylorhiza maculata (L.) Soó is a herbaceous perennial plant, native to Europe, but also found in Algeria, Morocco, western Siberia and Canada.

Different chromosome numbers (2n = 40, 40-41, 60, 78 and 80) are given in the literature for this species [START_REF] Ipcn | Index to plant chromosome numbers[END_REF][START_REF] Bertolini | Karyological and biometrical studies on some species of the genus Dactylorhiza Necker ex Nevski sec. Dactylorhiza (Orchidaceae) of Central-nothern Italy[END_REF][START_REF] Aagaard | A secondary hybrid zone between diploid Dactylorhiza incarnata ssp. cruenta and allotetraploid D. lapponica (Orchidaceae)[END_REF][START_REF] Siljak-Yakovlev | Towards a genome size and chromosome number database of Balkan flora: C-values in 343 taxa with novel values for 242[END_REF], and our count of 2n = 40 is in accordance with previous reports for diploids. [START_REF] Siljak-Yakovlev | Towards a genome size and chromosome number database of Balkan flora: C-values in 343 taxa with novel values for 242[END_REF] estimated the genome size for diploids (2C = 6.80 pg) and [START_REF] Aagaard | A secondary hybrid zone between diploid Dactylorhiza incarnata ssp. cruenta and allotetraploid D. lapponica (Orchidaceae)[END_REF] for tetraploids (2C = 11.32 pg). .

Digitalis grandiflora

BH Papratnica,Žepče,serpentine,44° 26' 13,33'' N,17° 58' 39,33'' E,333 m a.s.l.,29 Jun 2008, private herbarium of F.P.

Digitalis grandiflora Mill. is a herbaceous biennial or perennial plant, native to southern Europe and Asia.

The diploid chromosome number 2n = 56 is stable for the species and coincides with data obtained by different authors [START_REF] Fedorov | Chromosome numbers of flowering plants[END_REF][START_REF] Ipcn | Index to plant chromosome numbers[END_REF][START_REF] Vidic | Selective significance of genome size in a plant community with heavy metal pollution[END_REF][START_REF] Temsch | Heavy metal pollution, selection, and genome size: The species of the Žerjav study revisited with flow cytometry[END_REF][START_REF] Pustahija | Small genomes dominate in plants growing on serpentine soils in West Balkans, an exhaustive study of 8 habitats covering 308 taxa[END_REF]. Estimated genome sizes for the species are 2C = 2.30 pg [START_REF] Temsch | Heavy metal pollution, selection, and genome size: The species of the Žerjav study revisited with flow cytometry[END_REF], 2.56 pg [START_REF] Pustahija | Small genomes dominate in plants growing on serpentine soils in West Balkans, an exhaustive study of 8 habitats covering 308 taxa[END_REF]) and 2.60 pg [START_REF] Vidic | Selective significance of genome size in a plant community with heavy metal pollution[END_REF].

1930. Narcissus obsoletus (Haw.) Spach -2n = 30 (Fig. 2a).

Ct: Lovište, Pelješac Peninsula, limestones, 43° 02' 47,32'' N, 17° 00' 10,33'' E, 12 m a.s.l., 19 Oct 2008, private herbarium of E.M.Š.

Narcissus obsoletus (Haw.) Spach is a bulbous herbaceous perennial plant, native to the Mediterranean littoral with geographical distribution from northern Africa and the Iberian Peninsula to Israel on east. This is the first finding of this species for the Croatian flora identified also thanks to count of chromosome number 2n = 30 and analysis of chromosome complement, which is in Narcissus poeticus L. is a bulbous herbaceous perennial plant, native to central and southern Europe and cultivated, as a horticultural species, throughout the world.

The diploid chromosome number 2n = 14+0-2Bs is reported by several authors [START_REF] Fedorov | Chromosome numbers of flowering plants[END_REF][START_REF] Ipcn | Index to plant chromosome numbers[END_REF][START_REF] Zonneveld | The systematic value of nuclear DNA content for all species of Narcissus L. (Amaryllidaceae)[END_REF][START_REF] Siljak-Yakovlev | Towards a genome size and chromosome number database of Balkan flora: C-values in 343 taxa with novel values for 242[END_REF][START_REF] Pustahija | Small genomes dominate in plants growing on serpentine soils in West Balkans, an exhaustive study of 8 habitats covering 308 taxa[END_REF] as well as triploid chromosome number 2n = 21 [START_REF] Fedorov | Chromosome numbers of flowering plants[END_REF][START_REF] Ipcn | Index to plant chromosome numbers[END_REF] [START_REF] Brandham | The chromosomes of species, hybrids and cultivars of Narcissus L. (Amaryllidaceae)[END_REF][START_REF] Siljak-Yakovlev | Towards a genome size and chromosome number database of Balkan flora: C-values in 343 taxa with novel values for 242[END_REF]). Here we confirm chromosome numbers of diploids 2n = 14 + 0-2Bs and triploids 2n = 21 + 0-3Bs. Genome sizes of diploids were 24.33 (Siljak-Yakovlev & al. 2010), 26.00 [START_REF] Zonneveld | The systematic value of nuclear DNA content for all species of Narcissus L. (Amaryllidaceae)[END_REF], 27.50 pg [START_REF] Olszewska | Relationship between 2C DNA content, life-cycle, systematic position & level of DNA endoreplication in parenchyma cell nuclei during root growth and differentiation in some monocots[END_REF], and for triploids 2C = 34.55 pg [START_REF] Siljak-Yakovlev | Towards a genome size and chromosome number database of Balkan flora: C-values in 343 taxa with novel values for 242[END_REF].

1932. Narcissus tazetta L. -2n = 18 (Fig. 2e).

Le: El Aleli, limestones, 30 m a.s.l., 13 Apr 2012, leg. M. Bou Dagher-Kharrat s.n.

Narcissus tazetta L. is a bulbous herbaceous perennial and ornamental plant, native to the Mediterranean region from Portugal to Turkey, but widespread all over the world.

In the literature, very diverse reports are present for this species in relation to its chromosome number: 2n = 14, 20, 21, 22, 24, 28, 30 and 32 (Fedorov 1969;[START_REF] Ipcn | Index to plant chromosome numbers[END_REF][START_REF] Brandham | The chromosomes of species, hybrids and cultivars of Narcissus L. (Amaryllidaceae)[END_REF][START_REF] Zonneveld | The systematic value of nuclear DNA content for all species of Narcissus L. (Amaryllidaceae)[END_REF][START_REF] Bennett | Angiosperm DNA C-values database (release 8.0[END_REF][START_REF] Boukhenane | Cytogenetic characterization of six populations of Narcissus tazetta L. (Amaryllidaceae) from western Mediterranean[END_REF]). Here we present, for the first time, the chromosome number 2n = 18 that we found in one Lebanon population. This finding merites to be deepened. Three different genome sizes are published for this species 2C = 25 pg [START_REF] Dagher-Kharrat | Nuclear DNA C-values for biodiversity screening: Case of the Lebanese flora[END_REF]), 2C = 30.30 [START_REF] Zonneveld | The systematic value of nuclear DNA content for all species of Narcissus L. (Amaryllidaceae)[END_REF], 39.54 pg [START_REF] Vesely | Genome size and DNA base composition of geophytes: the mirror of phenology and ecology?[END_REF].

1933.

Platanthera bifolia (L.) Rich. -2n = 42 (Fig. 1e).

BH: Katranica, Muške Vode, Kladanj, serpentine, 44° 14' 11,64'' N, 18° 34' 17,87'' E, 825 m a.s.l., 06 May 2008, private herbarium of F.P.

Platanthera bifolia (L.) Rich. is a tuberculous herbaceous perennial plant, native to Europe, Asia-Temperate, Algeria and Tunisia.

The diploid chromosome number 2n = 42 is in accordance with the most aviable literature data [START_REF] Fedorov | Chromosome numbers of flowering plants[END_REF][START_REF] Ipcn | Index to plant chromosome numbers[END_REF][START_REF] Siljak-Yakovlev | Towards a genome size and chromosome number database of Balkan flora: C-values in 343 taxa with novel values for 242[END_REF] but not with 2n = 16 and 40 [START_REF] Ipcn | Index to plant chromosome numbers[END_REF]. Estimated amounts of nuclear DNA were 2C = 13.74 and 19.89 pg by [START_REF] Siljak-Yakovlev | Towards a genome size and chromosome number database of Balkan flora: C-values in 343 taxa with novel values for 242[END_REF][START_REF] Vesely | Genome size and DNA base composition of geophytes: the mirror of phenology and ecology?[END_REF], respectively. 1934. Polygonatum odoratum (Mill.) Druce -2n = 20 (Fig. 1f).

BH: Katranica, Muške Vode, Kladanj, serpentine, 44° 14' 11,64'' N, 18° 34' 17,87'' E, 825 m a.s.l., 06 May 2008, private herbarium of F.P.

Polygonatum odoratum (Mill.) Druce is a rhizomatous herbaceous perennial plant, native to Europe, Caucasus, Siberia, Russian Far East, China, Mongolia, Korea and Japan.

A very diverse chromosome number for the species can be found in the literature 2n = 16, 18, 20, 20+0-2Bs, 22, 24, 30 and 40 (Fedorov 1969;[START_REF] Ipcn | Index to plant chromosome numbers[END_REF][START_REF] Siljak-Yakovlev | Towards a genome size and chromosome number database of Balkan flora: C-values in 343 taxa with novel values for 242[END_REF], where the 2n = 20 that we found is the most common. Measured genome sizes are

Fig. 1 .

 1 Fig. 1. Mitotic methaphase plates of: a, Anacamptis morio, 2n = 36; b, Asphodelus albus, 2n = 28; c, Dactylorhiza maculata, 2n = 40; d, Digitalis grandiflora, 2n = 56; e, Platanthera bifolia, 2n = 42; f, Polygonatum odoratum, 2n = 20. -Scale bars = 10 μm.

  agreement with data obtained by Díaz Lifante & al. (2009). Siljak-Yakovlev & al. (2010) published its genome size but as N. serotinus L. 2C = 43.85 pg. 1931. Narcissus poeticus L. -2n = 14, 14+1-2Bs & 21+0-3Bs (Figs 2b, c & d). BH: Katranica, Muške Vode, Kladanj, serpentine, 44° 14' 11,64'' N, 18° 34' 17,87'' E, 825 m a.s.l., 06 May 2008, private herbarium of F.P. -Donje Peulje, Bosansko Grahovo, limestone, 44° 08' 42,81'' N, 16° 27' 48,12'' E, 810 m a.s.l., 10 May 2008, private herbarium of F.P. -Avtovac, Gatačko Polje, Gacko, limestones, 43° 07' 49,40'' N, 18° 34' 01,46'' E, 949 m a.s.l., 13 May 2008, private herbarium of F.P.

Fig. 2 .

 2 Fig. 2. Mitotic methaphase plates of Narcissus: a, N. obsoletus, 2n = 30; b, N. poeticus, 2n = 14 (population Katranica); c, N. poeticus, 2n = 14+1B (population Donje Peulje); d, N. poeticus, 2n = 21+3Bs (population Avtovac); e, N. tazetta, 2n = 18. -Arrows indicate the B chromosomes. Scale bars = 10 μm.

Acknowledgments

The authors are grateful to M. Bou Dagher-Kharrat for collecting Narcissus tazetta bulbs.

 2C = 19.66 (Siljak-Yakovlev & al. 2010), 20.04 [START_REF] Vesely | Genome size and DNA base composition of geophytes: the mirror of phenology and ecology?[END_REF]) and 23.10 pg (Zonneveld & al. 2005).


C Haynaldiiformis Prodan

C Nitida

C Strobilacea

Seven Centaurea species from Croatia (C. alba, C. calcitrapa, C. cristata, C. rhenana, C. rupestris, C. salonitana and C. solstitialis) belonging to five sections were studied. Chromosome numbers and metaphase plates are presented. All species studied here were found to be either diploid or tetraploid with the exception of C. salonitana which presented both ploidy levels: one diploid and one tetraploid population were

It is biennial plant that belongs to the European-Mediterranean floral element. This species is found in ruderal anthropogenic habitats and it is native to south-eastern Europe and Asia Minor, but also naturalized in Western and Central Europe, Africa, West Asia up to NW India (Dostál 1976;[START_REF] Nikolić | Flora Croatica Database[END_REF].

According to relevant literature [START_REF] Fedorov | Chromosome numbers of flowering plants[END_REF][START_REF] Ipcn | Index to plant chromosome numbers[END_REF], this species has a stable chromosome number 2n = 20 that we also found. Bartl. -2n = 4x = 36 (Fig. 1C).

Centaurea cristata

Ct: Kaštela,Kozjak,Split,limestones,43° 33' 26,48'' N,16° 18' 13,86'' E,154 m a.s.l., 12 Jul 2016, FNST_DB_2016_CC_19. Dostál (The Plant List 2013)], which belongs to Arenariae (Hayek) Dostál section, is biennial Illyrian-Adriatic endemic knapweed. This species is making the sub-Mediterranean and epi-Mediterranean eastern Adriatic dry lawns along the coastal slopes of the Croatian Littoral from the island Krk to the Neretva river in the Mediterranean vegetation zone (Dostál 1976;[START_REF] Nks | Nacionalna klasifikacija staništa, Državni zavod za zaštitu prirode Republike Hrvatske[END_REF][START_REF] Nikolić | Flora Croatica Database[END_REF].

Centaurea cristata

The chromosome count for this taxon 2n = 36 confirms the data reported by Lovrić (1982).

Centaurea rhenana

Boreau -2n = 4x = 36 (Fig. 1D). Thell.], belongs to Maculosae Dostál section and is a biennial or perennial plant. Its distribution range is quite wide, across the lawns and rocks of Central and South-Eastern Europe to the central Russia (Dostál 1976;[START_REF] Nikolić | Flora Croatica Database[END_REF].

Ct

The tetraploid chromosome number 2n = 4x = 36, found in this study, confirms previous reports [START_REF] Fedorov | Chromosome numbers of flowering plants[END_REF][START_REF] Ipcn | Index to plant chromosome numbers[END_REF][START_REF] Bancheva | Genome size in Bulgarian Centaurea s.l. (Asteraceae)[END_REF], but diploid individuals are also recorded 2n = 18, 18+0-2Bs in available literature [START_REF] Ipcn | Index to plant chromosome numbers[END_REF][START_REF] Bancheva | Genome size in Bulgarian Centaurea s.l. (Asteraceae)[END_REF]. Different 2C values, corresponding to two ploidy levels, were measured for this species: 1.70, 1.76, 1.84, 3.10, 3.16, 3.20 and 3.30 pg [START_REF] Bennett | Angiosperm DNA C-values database (release 8.0[END_REF][START_REF] Gsad ; Garnatje | GSAD: a genome size database in the Asteraceae[END_REF]. In our study only tetraploid individuals were recorded.

1923. Centaurea rupestris L. -2n = 2x = 20 (Fig. 1E). (Dostál 1976;[START_REF] Zepigi | Centaurea rupestris L. -Fiordaliso giallo[END_REF][START_REF] Nikolić | Flora Croatica Database[END_REF].

Ct

The diploid chromosome number 2n = 20 has been reported by [START_REF] Siljak | [END_REF], [START_REF] Siljak-Yakovlev | Nuclear DNA content and chromosome number in some diploid and tetraploid Centaurea (Asteraceae: Cardueae) from the Dalmatia region[END_REF] and [START_REF] Van Loon | (ed.) IOPB chromosome number reports LXVIII[END_REF], but additionally the somatic number 2n = 24 was reported [START_REF] Fedorov | Chromosome numbers of flowering plants[END_REF][START_REF] Van Loon | (ed.) IOPB chromosome number reports LXVIII[END_REF]). Here we confirm 2n = 20 chromosomes. Siljak-Yakovlev & al. (2010) reported genome sizes for the species 2C = 2.33 and 3.50 pg.

Centaurea salonitana

Vis. -2n = 2x = 20 (Fig. 1F) and 2n = 4x = 40.

Ct: Kijevo, Mt. Dinara, limestones, 43° 59' 38,44'' N, 16° 24' 07,49'' E, 447 m a.s.l., 17 Jun 2016, FNST_DB_2016_CS_7. -2n = 2x = 20. -Žnjan, Split, limestones, 43° 30' 29,24'' N, 16° 29' 36,03'' E, 72 m a.s.l., 16 (Dostál 1976;[START_REF] Nikolić | Flora Croatica Database[END_REF]).

We found one diploid (2n = 20) and one tetraploid (2n = 4x = 40) population. The diploid chromosome number confirms previous reports [START_REF] Fedorov | Chromosome numbers of flowering plants[END_REF]Siljak-Yakovlev & Gorenflot 1977;[START_REF] Ipcn | Index to plant chromosome numbers[END_REF], as well as the tetraploid number that confirms findings of Siljak-Yakovlev & Gorenflot (1977) and [START_REF] Ipcn | Index to plant chromosome numbers[END_REF].

  Centaurea calcitrapa L. [Syn.: Calcitrapa calcitrapa (L.) Hill, C. hybrida Sweet, C. hypophaestum Gaertn., C. lanceolata Lam., C. myacantha Cass., C. phoenicea Sweet, C. stellaris Hill, C. stellata Lam., C. vulgaris Bernh., Centaurea adulterina Moretti ex DC., C. calcitrapoides L., C. carduifolia Salisb., C. devauxii Nyman, C. horrida Ten., C. hybrida Chaix, C. macroacantha Guss., C. myacantha DC., C. penicillata Delile, C. trichacantha Willd. ex Spreng. (The Plant List 2013)], belongs to Dumulosae (Hayek) Dostál section.

Fig. 1 .

 1 Fig. 1. Mitotic methaphase plates of Centaurea: A, C. alba, 2n = 14; B, C. calcitrapa, 2n = 20; C, C. cristata, 2n = 36; D, C. rhenana, 2n = 30; E, C. rupestris, 2n = 20; F, C. salonitana, 2n = 20; G, C. solstitialis, 2n = 16. -Scale bar = 10 μm.

  Bartl. [Syn.: Acosta cristata (Bartl.) Holub, C. acutiloba DC., C. cristata subsp. rabenhorstiana (Sch. Bip.) Nyman, C. karschiana Auersw. ex Nyman, C. rabenhorstiana Sch. Bip. ex Nyman, C. scopolii Vest, C. spinosociliata subsp. cristata (Bartl.)

  Acrolophus rhenanus (Boreau) A. Löve & D. Löve, Centaurea maculosa Lam. subsp. rhenana (Boreau) Gugler, C. paniculata var. rhenana (Boreau) Rouy, C. stoebe L., C. stoebe L. subsp. stoebe, C. stoebe subsp. maculosa (Lam.) Hayek, C. stoebe subsp. rhenana (Boreau) Schinz &

	: Pasjača, Konavoske Stijene, Konavli, limestones, 42° 34' 52,81'' N, 18° 14' 59,97''
	E, 163 m a.s.l., 25 Jun 2016, FNST_DB_2016_CR_17.

Centaurea rhenana Boreau [Syn.: Acosta rhenana (Boreau) Soják,

  Centaurea rupestris L. [Syn.: Acrocentron tenuifolium Cass., Calcitrapa rupestris (L.) Sweet, Centaurea adonidifolia Rchb., C. rupestris subsp. aculeata Arcang., C. saxatilis Bertol. ex Nyman, C. variabilis Bartl. ex Steud., Colymbada rupestris (L.) Holub) (The Plant List 2013)], belongs to section Acrocentron (Cass.) DC. It is a biennial plant, present on the two shores of the Adriatic and South East Europe, above all in the Carpathian-Danubian region, in the Epi-Mediterranean vegetation zone

	: Pustinja Blaca, Klis, Split, limestones, 43° 34' 15,17'' N, 16° 28' 38,51'' E, 435 m
	a.s.l., 12 Jul 2016, FNST_DB_2016_CR_16.

  Centaurea salonitana Vis. [Syn.: Acrocentron salonitanum (Vis.) Á. Löve & D. Löve, Centaurea centauroides M. Bieb., C. collina var. macracantha DC., C. latifolia Pers., C. latisquama DC., C. latisquama subsp. salonitana (Vis.) Nyman, C. liliniea Velen., C. neglecta Besser, C. reflexa subsp. salonitana (Vis.) Mikheev, C. salonitana var. macracantha (DC.) Boiss. & Heldr., C. salonitana var. macracantha DC., C. salonitana var. subinermis Boiss., C. stribrnyi Velen., C. tatarica Pall., Colymbada salonitana (Vis.) Holub, Crepula centauroides (L.) Hill) (The Plant List 2013)], belongs to section Acrocentron (Cass.) DC., is a perennial plant, widespread on the lawn sand rocky meadows of South East and Central Europe

	Jun
	2016, FNST_DB_2016_CS_12. -2n = 4x = 40.

Acknowledgments

This work has been supported by Croatian Science Foundation under the project IP-2014-09-6897.

1925. Centaurea solstitialis L. -2n = 2x = 16 (Fig. 1G).

Ct: Marjan,Split,limestones,43° 30' 31,37'' N,16° 25' 59,18'' E,64 m a.s.l.,12 (Dostál 1976;[START_REF] Nikolić | Flora Croatica Database[END_REF].

Different authors [START_REF] Fedorov | Chromosome numbers of flowering plants[END_REF][START_REF] Ipcn | Index to plant chromosome numbers[END_REF][START_REF] Bennett | Angiosperm DNA C-values database (release 8.0[END_REF] counted the same chromosome number (2n = 16), but also 2n = 18 can be found in the literature [START_REF] Ipcn | Index to plant chromosome numbers[END_REF]. [START_REF] Bancheva | Genome size in Bulgarian Centaurea s.l. (Asteraceae)[END_REF] estimated genome size for C. solstitialis 2C = 1.74 pg and [START_REF] Carev | Phytochemical and cytogenetic characterization of Centaurea solstitialis (Asteraceae) from Croatia[END_REF] reported higher value of 2C = 1.95 pg.


Joan Vallès
email: joanvalles@ub.edu

Sadia Malik

Mario Gomez

Sonja Siljak-Yakovlev
email: sonia.yakovlev@u-psud.fr

Contribution to knowledge about nuclear DNA amounts in the family Asteraceae: first assessments in one genus and 12 species, with chromosome counts for three taxa

Keywords: 2C-value, Asteraceae, Compositae, flow cytometry, nuclear DNA amount, vascular plants

We present in this paper the first assessments, made by means of flow cytometry, of nuclear DNA amounts in one genus, 11 species, and one variety (including the first data from wild material in the case of one of the species), all of them from the family Asteraceae. Chromosome numbers are provided for three of these taxa, the presented material including new data for one species. These data complement existing information on plant genome size in the largest plant family.

INTRODUCTION

Genome size, i.e., the amount of nuclear DNA in living organisms, is a fundamental biological character [START_REF] Leitch | Evolution of DNA amounts across land plants (embryophyta)[END_REF]. When [START_REF] Swift | The constancy of desoxyribose nucleic acid in plant nuclei[END_REF] proposed the term C-value to define the DNA content of the unreplicated gametic chromosome set of an individual, it was considered characteristic and invariable (the C standing for constant) for every taxon. Since then, genuine intraspecific genome size variation has often been detected (Gregory 2005;Leitch et al. 2013 and references therein), and several terms have been coined to represent different concepts in this field [START_REF] Greilhuber | The origin, evolution and proposed stabilization of the terms 'Genome size' and 'C-value' to describe nuclear DNA contents[END_REF]. Nuclear DNA content is correlated with many biotic and abiotic characters [START_REF] Leitch | Evolution of DNA amounts across land plants (embryophyta)[END_REF]. Flow cytometry has shown itself to be the easiest and most productive method for assessment of nuclear DNA amounts, although other techniques, such as Feulgen microdensitometry, have been employed as well (Doležel et al. 2007 and references therein). Despite its relevance and the efforts of investigators to increase knowledge of this parameter by one method or another, genome size is currently known for only about 2% of angiosperms (Bennett & Leitch 2011).

The chromosome number is one of the most basic karyological and cytogenetic characters, constituting information relevant for plant systematic and evolutionary assessments [START_REF] Stuessy | Plant taxonomy. The systematic evaluation of comparative data[END_REF][START_REF] Stuessy | Multiple sources of comparative data for creative monography[END_REF]. It is a parameter that is obviously correlated with genome size, especially in polyploid taxa [START_REF] Leitch | Evolution of DNA amounts across land plants (embryophyta)[END_REF]. Despite the ease of its determination, the chromosome number has been reported for only slightly more than 25% of angiosperm taxa [START_REF] Stuessy | Plant taxonomy. The systematic evaluation of comparative data[END_REF] or for only 20% according to [START_REF] Rice | The Chromosome Counts Database (CCDB) -a community resource of plant chromosome numbers[END_REF].

The family Asteraceae Martinov or Compositae Giseke is the largest of plant families in terms of species number. It comprises many economically important plants, including some crops, and is one of the most cosmopolitan plant families, being abundantly present in all parts of the world except in Antarctic lands (Kadereit & Jeffrey 2007;Funk et al. 2009). In this family, which has been highly studied from many viewpoints, the number of species with available information about genome size information is greater than in angiosperms in general, but still only approaches 5% [START_REF] Garcia | Recent updates and developments to plant genome size databases[END_REF]. In Artemisia L., the Asteraceae genus with the most species studied from this viewpoint [START_REF] Garcia | Recent updates and developments to plant genome size databases[END_REF], roughly 25% of the taxa have genome size records to date, while chromosome numbers have been reported for almost 62% of the taxa [START_REF] Vallès | Biology, genome evolution, biotechnological issues, and research including applied perspectives in Artemisia (Asteraceae)[END_REF].

Research on angiosperm genome size has often been encouraged (Bennett & Leitch 2011;[START_REF] Galbraith | The genomes of all angiosperms: a call for a coordinated global census[END_REF], and work on angiosperm chromosome numbers has also been seen as necessary [START_REF] Stuessy | Plant taxonomy. The systematic evaluation of comparative data[END_REF][START_REF] Stuessy | Multiple sources of comparative data for creative monography[END_REF]. With precise figures, Bennett & Leitch (2011) proposed a target of DNA amount assessment in 2,500 angiosperm species in the period 2012-2016, whereas [START_REF] Garcia | Recent updates and developments to plant genome size databases[END_REF] envisaged research on 1,200 species of the family Astereaceae in the period 2014-2018.

Following these recommendations and centring on the family Asteraceae, in this paper we set out 1) to obtain novel information about plant nuclear DNA amounts in some taxa of this family; and 2) to complement, in some cases, these genome size estimates with determination of the chromosome number in the same populations. Consistent with this, only plants with unreported nuclear DNA content (in one case, with unknown genome size in wild populations) were taken into account in the study. Chromosome counts were performed whenever possible, paying special attention to taxa in which such data are The total nuclear DNA amount was assessed by flow cytometry according to [START_REF] Marie | A cytometric exercise in plant DNA histograms, with 2C values for 70 species[END_REF]. Young leaves or cotyledons of the analysed individuals and the internal standards were chopped together using a razor blade in a plastic Petri dish with 1200 μl of LB01 isolation buffer [START_REF] Doležel | Analysis of nuclear DNA content in plant cells by flow cytometry[END_REF]Barcelona) or 1 ml of Gif nuclei-isolation buffer, which is slightly modified Galbraith's buffer [START_REF] Galbraith | Rapid flow cytometric analysis of the cell cycle in intact plant tissues[END_REF]): 45 mM MgCl 2 , 30 mM sodium citrate, 60 mM MOPS (4-morpholine propane sulphonate, pH 7), and 1% (w/v) polyvinylpyrrolidone 10000, pH 7.2) containing 0.1% (w/v) Triton X-100, supplemented with 5 mM sodium metabisulphite and RNase (2.5 U/ml) (Gif). Barcelona's buffer was also supplemented with 100 μg/ ml of ribonuclease A (RNase A, Roche, France). The suspension was filtered through 70 (Barcelona) or 50 (Gif)-μm nylon mesh. The nuclei were stained with 60 (Barcelona) or 50 (Gif) μg/ml propidium iodide, a specific DNA intercalating fluorochrome dye, and kept at least 5 min at 4°C. Between 5000 and 10000 stained nuclei were measured for each sample using either a flow cytometer with a 488-nm 15 mW laser (Epics XL, Beckman Coulter, Brea, CA, USA; Barcelona) or one with a 532-nm 30 mW laser (CyFlow SL3, Partec, Munster, Germany; Gif). The total holoploid nuclear DNA content (2C) was calculated using the linear relationship between the fluorescent signals from stained nuclei of the investigated species and the internal standard. The mean 2C-value as well as the standard deviation of the mean and its coefficient of variation (%) were calculated from measurements of samples comprising two to five individuals (one individual -in two replicates in one case, i.e., that of a second, complementary population of one taxon) according to the samples.

Chromosome number determination.

Achenes were germinated on wet filter paper in Petri dishes at room temperature. Young plants were grown in pots in greenhouse conditions. Root tips obtained from the seedlings or from the potted plants were pretreated with 0.05% aqueous colchicine at room temperature for from 1 h 30 min to 2 h 45 min and then fixed in absolute ethanol and glacial acetic acid (3:1) for at least 12 hours at 4°C. Root tips were hydrolysed in 1 M HCl for 1-5 minutes at 60°C, washed in distilled water at room temperature, and stained in 1% orcein in 45% acetic acid for 0.5-12 hours at room temperature. Root tip meristems were squashed in a droplet of 45% acetic acid and glycerol (9:1) and observed in Zeiss Axioplan (Barcelona) or Zeiss Axiophot (Orsay) microscopes, where the best metaphase plates were photographed using an Axiocam HRm camera (Zeiss, Oberkochen, Germany; Barcelona) or a CCD camera (RETIGA 2000R; Princeton Instruments, Evry, France; Orsay).

RESULTS AND DISCUSSION

Data on nuclear DNA content (mean 2C-values per taxon studied) of the 14 populations (12 taxa) studied, including standard deviations and coefficients of variation, are presented in Table 2. The coefficients of variation range from 0.57 to 3.56% (mean value, 1.65), indicating reliable and reproducible estimates, and uniform populations.

According to the sources mentioned in the Materials and Methods section, the obtained values are the first genome size data for all the taxa considered, in most cases at the specific level and in one case, Artemisia sericea Weber ex Stechm. var. nitens (Steven ex Besser) Steven ex Krasch., at the varietal level. For Artemisia vallesiaca All., this is the first determination in a wild population, the results (2C = 9.82 pg) being close to previous reports on plants cultivated in a botanical garden (2C = 9.81, 9.13 pg; [START_REF] Garcia | Genome size variation in the Artemisia arborescens complex (Asteraceae, Anthemideae) and its cultivars[END_REF][START_REF] Pellicer | Genome size dynamics in Artemisia L. (Asteraceae): following the track of polyploidy[END_REF]. The nuclear DNA content found in Artemisia sericea var. nitens (2C = 23.68 pg) is not very different from that previously reported for the species (without subspecies indication; 2C = 23.33, 23.95, and 24.71 pg;[START_REF] Pellicer | Genome size dynamics in Artemisia L. (Asteraceae): following the track of polyploidy[END_REF]. Finally, the nuclear DNA amount is here estimated for the first time in one genus, Psiadia Jacq. ex Willd.

The chromosome number is provided for the first time for Artemisia densiflora Viv. This number (2n = 18), indicating a diploid level, coincides with that of A. caerulescens L. [START_REF] Vallès | Étude biosystématique du groupe d'Artemisia caerulescens dans la Péninsule Ibérique et les Îles Baléares[END_REF], under which this taxon has been combined [A. caerulescens subsp. densiflora (Viv.) Gamisans ex Kerguélen & Lambinon], although molecular data do not support a close relationship between the two species [START_REF] Malik | Phylogeny and biogeography of Artemisia subgenus Seriphidium (Asteraceae: Anthemideae)[END_REF]. For Bidens alba (L.) DC. and Urospermum picroides (L.) Scop. ex F.W.Schmidt, numbers of 2n = 48 and 10, respectively, have now been confirmed [START_REF] Queirós | Contribuição para o conhecimento citotaxonomico das Spermatophyta de Portugal. II. Compositae, supl. I[END_REF][START_REF] Tereza | Chromosomal studies of three species of Bidens L. (Asteraceae)[END_REF]. Metaphase plates of our counts are presented in Fig. 1.

The nuclear DNA amounts here recorded are rather small or medium-sized. According to the categories established by [START_REF] Leitch | Evolution of DNA amounts across land plants (embryophyta)[END_REF], one out of the 12 (8.3%) genome sizes estimated here falls within the category of very small (2C < 2.8 pg), whereas most of them [eight (66.7%)] are small (2.8 ≤ 2C < 7), three (25%) are intermediate (7 ≤ 2C < 28), and none is large (28 ≤ 2C ≤ 75) or very large (2C > 75). As for the ploidy level, diploids dominate, complemented by the presence of a few polyploids (three tetraploids and one decaploid).

The 2C values here assessed vary from 1.37 to 23.68 pg, values falling within the range of the family, viz., from 0.72 to 142.0 pg (http://www.asteraceaegenomesize.com, updated December 31, 2016, accessed January 25, 2017). All reports are first estimates; one and two asterisks (*) indicate a genome size report obtained for the first time from wild materials (in a species for which genome size had been previously assessed only from botanical garden materials) and a report new for a genus, respectively.

2 1 pg = 978 Mbp [START_REF] Doležel | Nuclear DNA content and genome size of trout and human[END_REF]).

3 See the Materials and Methods section for details. 4 One and two plus signs (+) indicate, respectively, our own counts in this paper and data from K. Watanabe's Index to chromosome numbers in Asteraceae (http://www.lib.kobe-u.ac.jp/infolib/meta_pub/engG0000003asteraceae, accessed January 25, 2017). Three plus signs indicate that the chromosome numbers are provided for the species without varietal identification.

At the species level, according to the same database, most of our values also fall within the range of variation known for their respective genera, with two exceptions.

Figure 1 .

 1 Figure 1. Metaphase plates of Artemisia densiflora, population 1, 2n = 18 (A); Bidens alba, 2n = 48 (B); and Urospermum picroides, population 1, 2n = 10 (C). Scale bars = 10 μm.

Taxon 1 (tribe) Population and collection data (herbarium voucher) Life cycle

		1. Italy: Sardinia, Maddalena archipelago, Caprera island: Stagnali gulf, near Stagnali
	Artemisia densiflora Viv. (Anthemideae)	town. J. Vallès, 17/11/2015 (BCN 126584) 2. Italy: Sardinia, Maddalena archipelago, Maddalena island: Baia Trinità. J. Vallès,	Perennial
		17/11/2015 (BCN 126585)
	Artemisia integrifolia Richards. (Anthemideae)	Russia, Chitin oblast, Kyra, A.A. Korobkov MV19, 26/8/2005 (BCN 136548)	Perennial
	Artemisia kurramensis Qazilb. (Anthemideae)	Pakistan, Parachinar: Kurram Agency, Federally Administered Tribal Areas. Sh. Bibi, 5/2014 (ISL QAU26860)	Perennial
	Artemisia rutifolia Stephan ex Spreng. (Anthemideae)	Russia, Chitin oblast, Khapcharang, A.A. Korobkov MV4, 9/9/2005 (BCN 136546)	Perennial
	Artemisia sericea Weber ex Stechm.
	var. nitens (Steven ex Besser) Steven	Russia, Krasnoyarsk. N.V. Stepanov MV26, 14/10/2005 (BCN 136547)	Perennial
	ex Krasch. (Anthemideae)
	Artemisia vallesiaca All. (Anthemideae)	Switzerland, Valais: Sion, pathway to Montorge. J. Vallès & A. Vehí, 24/8/2014 (BCN 114077)	Perennial
	Baccharis halimifolia L. (Astereae)	France: Orsay, Université de Paris-Sud XI garden (001100), from eastern North America. S. Siljak-Yakovlev & J. Vallès, 7/1/2016 (BCN 127893)	Perennial
	Bidens alba (L.) DC. (Heliantheae)	France, Guadeloupe island, Guadeloupe Basse-Terre, Bouillante. S. Siljak-Yakovlev, 23/5/2014 (BCN 136549)	Annual
	Inula ensifolia L. (Inuleae)	Croatia: Biokovo mountain. S. Siljak-Yakovlev, 8/7/2016 (BCN)	Perennial
	Psiadia retusa DC. (Astereae)	France, Réunion island, cultivated in the Botanical garden from a wild population. S.

Siljak-Yakovlev, 8/3/2012 (BCN) Perennial Serratula radiata (Waldst. & Kit.) M.Bieb. (Cardueae) Croatia: Biokovo mountain. S. Siljak-Yakovlev, 8/7/2016 (BCN) Perennial Urospermum picroides (L.) Scop. ex F.W.Schmidt (Cichorieae) 1. Croatia, Dubrovnik, S. Siljak-Yakovlev, 8/6/2013 (BCN-S 2077) 2. Croatia, Makarska (Blato), S. Siljak-Yakovlev, 15/7/2015 (BCN-S 2078) Annual

Table 1 .

 1 Provenance and life cycle of the taxa studied.not yet available. To establish the status of novelty, we used four comprehensive and updated genome size and chromosome number databases, all of them accessed on January 25, 2017: the Kew plant DNA C-values database (http://data.kew.org/cvalues); FLOWer, a flow cytometrycreated plant DNA database (http://botany.natur.cuni.cz/ flower/index.php); GSAD, an Asteraceae genome size database (http://www.etnobiofic.cat/gsad); and the Index to chromosome numbers in Asteraceae (http://www.lib. kobe-u.ac.jp/infolib/meta_pub/engG0000003asteraceae).

	MATERIALS AND METHODS
	Materials. Fresh leaf material of the investigated taxa was
	collected for genome size measurements from adult plants
	or from seedlings. For adult plants, it was preserved in
	slightly humidified tissue paper and kept in a refrigerator
	until processing on the cytometer, less than one week
	after collection. For seedlings, the cotyledons were
	processed directly. Root tips from either plants living in
	pots or germinated seedlings were for chromosome
	counts. In addition, material for herbarium vouchers was
	collected, pressed, and deposited in one of two herbaria,

BCN (Centre de Documentació de Biodiversitat Vegetal, Universitat de Barcelona) or ISL (Biological Sciences Department, Quaid-I-Azam University, Islamabad). Data on plant origin and collection are provided in Table

1

, together with information about the life cycle type of the studied taxa.

Flow cytometry. Genome size was assessed either at the Centres Científics i Tecnològics, Universitat de Barcelona (hereafter Barcelona; Artemisia) or at the Institut des Sciences du Végétal, CNRS, Gif-sur-Yvette (hereafter Gif; other taxa), using in both cases the following three of five internal standards of the latter institution in order to cover the range of DNA contents: Solanum lycopersicum L. 'Montfavet 63-5' (2C = 1.99 pg,

[START_REF] Lepers-Andrzejewski | Diversity and dynamics of plant genome size: an example of polysomaty from a cytogenetic study of Tahitian vanilla (Vanilla x tahitensis, Orchidaceae)[END_REF]

; and Petunia hybrida Vilm. 'PxPc6' and Pisum sativum L. 'Long Express' (2C = 2.85 pg and 8.37 pg, respectively,

[START_REF] Marie | A cytometric exercise in plant DNA histograms, with 2C values for 70 species[END_REF]

.

Table 2 .

 2 Nuclear DNA content and chromosome numbers of the taxa studied.

	Taxon (tribe)	Number of individuals studied	2C in pg (standard deviation) 1	Coefficient of variation for this mean (%)	1C in Mbp 2	Internal standard 3	Chromosome number (2n) 4
	Artemisia densiflora Viv., population 1 (Anthemideae)	5	6.39 (0.08)	2.84	3125	Pisum	18 +
	Artemisia densiflora Viv., population 2 (Anthemideae)	1	6.37 (0.10)	2.75	3115	Pisum	18 +
	Artemisia integrifolia Richards. (Anthemideae)	5	5.22 (0.24)	2.50	2553	Pisum	18, 36 ++
	Artemisia kurramensis Qazilb. (Anthemideae)	5	5.58 (0.07)	2.50	2729	Petunia	18 ++
	Artemisia rutifolia Stephan ex Spreng. (Anthemideae)	5	5.56 (0.13)	0.85	2719	Petunia	18 ++
	Artemisia sericea Weber ex Stechm. var. nitens (Steven ex Besser) Steven ex Krasch. (Anthemideae)	5	23.68 (0,78)	0.59	11580	Pisum 18, 36, 90 ++,+++
	Artemisia vallesiaca All. (Anthemideae)	5	9.82 (0.09)*	3.56	4802	Pisum	36 ++
	Baccharis halimifolia L. (Astereae)	2	4.41 (0.08)	1.92	2156	Petunia	18 ++
	Bidens alba (L.) DC. (Heliantheae)	5	4.19 (0.03)	0.74	2049	Petunia	48 +
	Inula ensifolia L. (Inuleae)	3	3.62 (0.03)	0.73	1770	Solanum	16, 24 ++
	Psiadia retusa DC. (Astereae)	3	7.68 (0.04)**	0.57	3756	Petunia	?
	Serratula radiata (Waldst. & Kit.) M.Bieb. (Cardueae)	5	3.67 (0.02)	0.61	1795	Solanum	30, 60 ++
	Urospermum picroides (L.) Scop. ex F.W.Schmidt (Cichorieae), population 1	5	1.37 (0.02)	1.56	670	Solanum	10 +
	Urospermum picroides (L.) Scop. ex F.W.Schmidt, population 2	5	1.38 (0.01)	0.94	675	Solanum	10 +
	1

  Acknowledgements -The authors are grateful for the support received from the Centre National de la Recherche Scientifique (CNRS, France), the Agència per a la Gestió d'Ajuts Universitaris i de Recerca (AGAUR, Catalan government, project 2014SGR514), the Dirección General de Investigación (Spanish government, CGL2013-49097-C2-2-P), and the Higher Education Commission, Pakistan (International Research Support Initiative Program, 1-8/ HEC/HRD/2013/2794). In addition, we are indebted to the Conservatoire Botanique National de Mascarin, Saint Leu, La Réunion, and A.A. Korobkov (Botanical Institute, St. Petersburg) for providing us with material of some plant species, and Chari González (Centres Científics i Tecnològics, Universitat de Barcelona) is thanked for her assistance during flow cytometric work. Cytometry for some species was performed at the Imagerie-Gif core facility (http://www.i2bc.paris-saclay.fr).

	CONCLUDING REMARKS
	With just 1% of the 1,200 species that Garcia et al. (2014)
	proposed for study in the period 2014-2018, the present
	paper adds only a small amount of data to the knowledge
	of genome size in the family Asteraceae. Moreover, with
	three out of the 12 taxa (four out of the 14 populations)
	coming from Croatia (Inula ensifolia, Serratula radiata,
	and Urospermum picroides), it contributes nuclear DNA
	content information on plants from the Balkan region,
	where already ca. 15% of the flora has genome size data
	available (Vallès et al. 2014), thus modestly expanding
	the Balkan flora genome size database (Siljak-Yakovlev
	et al. 2010). Although the current dataset for genome
	size and chromosome numbers is numerically minor,
	we think that any new contribution to knowledge
	of those fundamental biological parameters should
	be considered valuable and ought to be encouraged.

The present recorded value for Baccharis hamilifolia (2C = 4.41 pg) represents the lowest value to date in the genus, the previous ones ranging from 4.78 to 6.72 pg. Serratula radiata (Waldst. & Kit.) M.Bieb. (Cardueae) has a genome size (2C = 3.67 pg) more than double that of the only other species of the genus for which such a parameter is available (S. pusilla Dittrich, 2C = 1.50 pg; Bou Dagher-Kharrat et al. 2013), which might indicate a higher ploidy level in the genus. Such contributions expand existing knowledge in the karyological/cytogenetic field and provide more data suitable for resolving many kinds of systematic and evolutionary issues related to different species or genera, including taxonomic aspects (Stuessy 2011). They are also valuable for meta-analytical work on larger groups, such as families or all angiosperms (Bennett & Leitch 2011; Garcia et al. 2014). REFERENCES Bennett MD & Leitch IJ. 2005. Nuclear DNA amounts in angiosperms -progress, problems and prospects. Annals of Botany 95: 45-90. Bennett MD & Leitch IJ. 2011. Nuclear DNA amounts in angiosperms: targets, trends and tomorrow. Annals of Botany 107: 467-590.

J. Vallès et al: DNA amounts in Asteraceae

U ovom radu su predstavljene prve procene, tečnom citometrijom, količine jedarne DNK za jedan rod, 11 vrsta i 1 varijetet (uključujući prve podatke za material iz prirode jedne od vrsta), svih iz familije Asteraceae. Broj hromozoma je prikazan za tri vrste, uklučujući nove podatke za jednu vrstu. Ovi podaci dopunjuju postojeće informacije o veličini genoma u najvećoj familiji biljaka.

Ključne reči: 2C-vrednost, Asteraceae, Compositae, tečna citometrija, količina jedarne DNK, vaskularne biljke.

Prilog poznavanju količine jedarne DNK u familiji

Asteraceae: prve procene za jedan rod i 12 vrsta, sa brojem hromozoma za tri vrste Joan Vallès, Sadia Malik, Mario Gomez i Sonja Siljak-Yakovlev REzIME