Marie-Christine Daunay'

Jean Winoc Hennarr'

Sylvia Sa

Jacques Dintinger'

Eggplant resistance to bacterial wilt and to Fusarium wilt: Is there a link?

INRA URI 052 maintains a germplasm collection of S. melongena and related species. The accessions of this collection that are described in the literature as resistant to Ralstonia solanacearum, agent responsible ofbacterial wilt, were screened at plantlet stage against Fusarium oxysporum f.sp. melongenae on the basis of the number ofleaves wilted and vessels browning. Results show that the panel of accessions tested display phenotypes ranging from fully resistant to fully susceptible to Fusarium wilt, with ail intermediate resistance levels. Results are discussed on the basis ofthe complexity ofresistance evaluation and of what is known in tomato about a link between resistances to both vascular diseases.

Introduction

Eggplant,Solanum melongena L., is susceptible to several vascular diseases of soil born origin, mainly Verticillium dahliae in cool temperate conditions, Fusarium oxysporum f.sp. melongenae in warm temperate conditions (sandy soils), and Ralstonia solanacearum in tropical and equatorial conditions. Resistances to each of these disease exist within the intraspecific and interspecific eggplant germplasm, although their genetic characteristics are variable. Fragmented experimental and literature information suggests the existence of sorne link(s) between resistances of eggplant, as weIl as of tomato, to these or other vascular diseases. By focusing on two pathosystems, eggplant on one side, Fusarium and bacterial wilt on the other side, our purpose is to investigate the possible relationship between eggplant resistances to both diseases. The first part is a literature based overview of the knowledge about the pathogens and eggplant resistances. Second part presents results obtained by testing with F. o. f. sp. melongenae a collection of eggplant genetic resources, chosen because described in the literature as resistant to bacterial wiIt (BW). Results are then discussed in light of the genetic and functional information available for eggplant, and to a lesser extent, tomato.

Eggplant and wilts pathosystems

Eggplant -Fusarium wilt pathosystem

Resistance to Fusarium wilt is available in S. melongena germplasm [START_REF] Kh | Resistance of eggp/ant to Fusarium wi/t. Se/ektsiya i Semenovodstvo[END_REF][START_REF] Mandare | Varietal screening and efJicacy of fungicides against Fusarium wilt ofbrinjal[END_REF][START_REF] Sakata | Evaluation of resistance to bacterial wilt and Verticillium wilt in eggplants (Solanum melongena L) collected in Malaysia[END_REF]. A monogenic dominant control was identified in eggplant accessions -LSI74, LS1934 and LS2436- [START_REF] Sakata | Evaluation of resistance to bacterial wilt and Verticillium wilt in eggplants (Solanum melongena L) collected in Malaysia[END_REF][START_REF] Mochizuki | Eggplant parental line 1, and eggplant breeding line resistant to Fusarium wilt[END_REF][START_REF] Mutlu | Development of SRAP, SRAP-RGA, RAPD and SCAR markers linked with a Fusarium wilt resistance gene in eggplant[END_REF][START_REF] Boyaci | Genetic analysis of resistance to wilt caused by Fusarium (Fusarium oxysporum f.sp. melongenae) in eggplant (Solanum melongena)[END_REF]. [START_REF] Miyatake | Detailed mapping of a resistance locus against Fusarium wilt in cultivated eggplant (Solanum melongena)[END_REF] 99 positionned at the end of chromosome 2 the locus (FMI) two allelic fonns of which were identified in LS174 (FmI") and LS1934 (FmI L ). Two closely linked SRAP and SRAP-RGA markers, mapped 1.2 cM from the LS2436 resistance gene were developed by MutIu et al. (2008) for marker assisted selection. The locus responsible of the resistance of S. melongena LS2436 was mapped on the middle of eggplant chromosome 4, syntenic to tomato chrA [START_REF] Miyatake | Detailed mapping of a resistance locus against Fusarium wilt in cultivated eggplant (Solanum melongena)[END_REF]).

Resistance to Fusarium wilt was also found in several Solanum species related to eggplant such as S. torvum, S. sisymbriifolium, S. aethiopicum, S. violaceum and others [START_REF] Yamakawa | Nature and inheritance of Fusarium wilt resistance in eggplant cultivars and related Solanum species[END_REF][START_REF] Cappelli | Sources of resistance among Solanum spp. to an Italian iso/ate of Fusarium oxysporum jsp[END_REF][START_REF] Cappelli | Sources of resistance among Solanum spp. to an Italian iso/ate of Fusarium oxysporum jsp[END_REF][START_REF] Monma | Evaluation ofresistance to bacterial, Fusarium and Verticillium wilt in eggplant and eggplant-related species collected in Ghana[END_REF][START_REF] Gousset | Solanum torvum, as a useful source of resistance against bacterial and fungal diseases for improvement of eggplant (S melongena L.)[END_REF][START_REF] Boyaci | Screening for resistance to Fusarium wilt of some cu/tivated eggplants and wild Solanum accessions[END_REF]. The genetic control of the resistance of two S. aethiopicum accessions belonging to cultigroups Aculeatum and Gilo, was shown as monogenic dominant, [START_REF] Rizza | Androgenic dihaploids from somatic hybrids between Solanum melongena and S aethiopicum group Gilo as a source of resistance to Fusarium oxysporumfsp[END_REF][START_REF] Toppino | Inheritance of Fusarium wilt resistance introgressed from Solanum aethiopicum Gilo and Aculeatum groups into cultivated eggplant (S melongena) and development of associated PCR-based markers[END_REF]. Progenies derived from anther culture and interspecific somatic hybrids 's. melongena X S. aethiopicum' [START_REF] Rotino | Current status in production and utilization of dihaploids from somatic hybrids between eggplant (Solanum melongena L.) and its wild relatives[END_REF] allowed [START_REF] Toppino | Inheritance of Fusarium wilt resistance introgressed from Solanum aethiopicum Gilo and Aculeatum groups into cultivated eggplant (S melongena) and development of associated PCR-based markers[END_REF] (i) to identify the locus Rfo-saI which controls the resistance of S. aethiopicum to Fusarium wilt, as well as (ii) its two allelic fonns, respectively specifie to groups Aculeatum and Gilo. Rfo-saI was positioned later on the eggplant Linkage Group 1 of [START_REF] Barchi | Segregation distortion and linkage analysis in eggplant (Solanum melongena L.)[END_REF]. [START_REF] Miyatake | Detailed mapping of a resistance locus against Fusarium wilt in cultivated eggplant (Solanum melongena)[END_REF] mapped Rfo-sal very close to FMI. AlI in aIl, three loci controlling Fusarium wilt resistance are identified today, two on S. melongena chromosome 2 (FMI and Rfo-saI, with two allelic forms each) and one on chromosome 4 [START_REF] Miyatake | Detailed mapping of a resistance locus against Fusarium wilt in cultivated eggplant (Solanum melongena)[END_REF]. So far, no interaction has been described between these loci and Fusarium strains, unlike monogenic resistances based on different mechanisms and controlling three Fusarium races in tomato (Gonzalez-Cendales, 2016). Further, in tomato polygenic tolerance has also been described [START_REF] Crill | Controlling Fusarium wilt of tomato with resistant varieties[END_REF].

Eggplant -bacterial wilt pathosystem

Resistance to BW, as in the case of Fusarium wilt, has been found in S. melongena germplasm. The resistances found in different accessions are described as dominant or recessive, monogenic or polygenic, depending on the accessions (compiled in [START_REF] Daunay | Eggplant[END_REF]. A first single dominant gene of resistance identified in the Chinese accession E-31, was marked with a SCAR marker distant from 3.33 cM [START_REF] Cao | Inheritance and identification of SCAR marker linked to bacterial wilt-resistance in eggplant[END_REF]. ln this accession, the function of a putative BW resistance gene (the same ?), named RE-bw, was characterized, including its interaction with the bacterial Popp2 avirulence factor [START_REF] Xi 'ou | Functional characterization of a putative bacterial wilt resistance gene (RE-bw) in eggplant[END_REF]. Another major dominant gene, ErsI, probably positionned on chromosome 9 controls the resistance of the INRA accession AG91-25 [START_REF] Lebeau | Genetic mapping of a major dominant gene of resistance to Ralstonia solanacearum in eggplant[END_REF]; its interactions with Ralstonia type ID effectors are under CUITentresearch (Peeters et al., pers. comm.). Ers-I is escorted by a few QTLs, the efficiency ofwhich depends on the bacterial strains used.

Resistances to BW have also been found in several Solanum species related to eggplant [START_REF] Hébert | Résistance comparée de 9 espèces du genre Solanum au flétrissement bactérien (pseudomonas solanacearum) et au nématode Meloidogyne incognita. Intérêt pour l'amélioration de l'aubergine (Solanum melongena l.) en zone tropicale humide[END_REF][START_REF] Clain | RAPD genetic homogeneity and higb levels of bacterial wilt tolerance in Solanum torvum Sw. (Solanaceae) accessions from Reunion island[END_REF][START_REF] Gousset | Solanum torvum, as a useful source of resistance against bacterial and fungal diseases for improvement of eggplant (S melongena L.)[END_REF][START_REF] Daunay | Eggplant[END_REF], in particular in S. torvum , S. aethiopicum, S. sisymbriifolium, and S. violaceum, sorne ofwhich are used as rootstocks for eggplant. This does not mean that aU accessions of each of these species are resistant to aIl strains. For instance susceptibility or partial susceptibility of sorne accessions of S. torvum [START_REF] Saito | Development of Solanum melongena breeding fines as resistant rootstocks to Verticillium, Bacterial and Fusarium wilts[END_REF][START_REF] Gousset | Solanum torvum, as a useful source of resistance against bacterial and fungal diseases for improvement of eggplant (S melongena L.)[END_REF] and S. aethiopicum [START_REF] Hébert | Résistance comparée de 9 espèces du genre Solanum au flétrissement bactérien (pseudomonas solanacearum) et au nématode Meloidogyne incognita. Intérêt pour l'amélioration de l'aubergine (Solanum melongena l.) en zone tropicale humide[END_REF] is mentionned. Further, bacteria can be isolated from rootsor lower stem of symptomless S. torvum [START_REF] Clain | RAPD genetic homogeneity and higb levels of bacterial wilt tolerance in Solanum torvum Sw. (Solanaceae) accessions from Reunion island[END_REF][START_REF] Gousset | Solanum torvum, as a useful source of resistance against bacterial and fungal diseases for improvement of eggplant (S melongena L.)[END_REF] which means that the resistance of this species, as in eggplant and tomato (Grimault & PriOT, 1994), is an ability to limit the upward spread ofthe bacteria within xylem vessels.

The resistance of S. aethiopicum was transferred into S. melongena by sexual interspecific crossing [START_REF] Ano | A new source of resistance to bacterial wilt of eggplants obtained from a cross Solanum aethiopicum x Solanum melongena[END_REF] as well as by proto pIast fusion (Collonnier et al., 2001b). Somatic hybrids between S. melongena on one hand, and S. torvum (Collonnier et al., 2003b) or S. sisymbriifolium on the other (Collonnier et al., 2003a), as weLl as somatic hybrids between S. integrifolium (= S. aethiopicum) and S. violaceum [START_REF] Tamura | A somatic hybrid between Solanum integrifolium and Solanum violaceum that is resistant to bacterial witt caused by Ralstonia solanacearum[END_REF] are as resistant or less than their resistant parent.

The major trouble the breeders face for creating resistant material to BW is the unstability accross locations of the resistances they use, whatever the solanaceous crop they work with [START_REF] Huet | Breedingfor resistances to Ralstonia solanacearum[END_REF], because of biotic (complexity of the pathogenic process, interactions of the resistances with local bacterial strains, synergy with root knot nematodes), as welI as abiotic reasons (influence ofsoil type and moisture, temperature and light intensity) [START_REF] Hayward | Biology and epidemiology ofbacterial wilt caused by Pseudomonas solanacearum[END_REF]. ln eggplant, as in tomato, the resistance is an ability to limit the spread of the bacteria within the stemxylem vessels [START_REF] Grimault | Invasiveness of Pseudomonas solanacearum in tomato, eggplant and pepper: a comparative study[END_REF]. This means that wilt is not a sufficient criteria for assessing resistance, and must be completed with a colonization index, as did [START_REF] Lebeau | Bacterial WiltResistance in Tomato, Pepper, andEggplant: Genetic Resources Respond to Diverse Strains in the Ralstonia solanacearum Species Complex[END_REF] who revealed the existence of compatible or incompatible interactions among a set of resistant accessions of both species. The wide genetic diversity of the thousands strains of Ralstonia solanacearum is another major impediment, The classification of the BW complex, initially based on host range (races), then on rnetabolic properties (biovars), has strongly evolved with the availability of molecular techniques, from which Sequevars, Clades, Phylotypes [START_REF] Fegan | How complex is the "Ralstonia solanacearum species complex[END_REF] were defined. The numerous pathogenicity components of the bacteria have been reviewed by [START_REF] Peeters | Ralstonia solanacearum, a widespread bacterial plant pathogen in the post-genomic era[END_REF]. New species have been defined recently within this complex (prior et al., 2016). On the whole, ail this méans that research on resistance spectrum, genetic determinism and/or functional characterization needs intimate genetic knowledge of the bacterial strains used, as was shown in [START_REF] Lebeau | Bacterial WiltResistance in Tomato, Pepper, andEggplant: Genetic Resources Respond to Diverse Strains in the Ralstonia solanacearum Species Complex[END_REF]. These authors exemplified the complexity of the interactions between a range ofbacterial strains representative of the diversity of the bacteria, and a core collection of resistant genitors of three solanaceous crops (eggplant, tomato and pepper).

Resistance to several vascular diseases

Resistance to both Fusarium and bacterial wilts is mentionned in the literature for some eggplant accessions, such as LS1934 and LS 2436 (e.g. [START_REF] Sakata | Evaluation of resistance to bacterial wilt and Verticillium wilt in eggplants (Solanum melongena L) collected in Malaysia[END_REF] as well as for several eggplant relatives such as S. aethiopicum Aculeatum and Gilo Groups, S. torvum, S. sisymbriifolium and S. violaceum (e.g. [START_REF] Narikawa | Collection of solanaceous plants in Malaysia and screening for disease resistance[END_REF]Collonnier et al., 2001a;[START_REF] Gousset | Solanum torvum, as a useful source of resistance against bacterial and fungal diseases for improvement of eggplant (S melongena L.)[END_REF][START_REF] Daunay | Eggplant[END_REF]. However, the available data are limited in terms (i) of number of accessions tested for each Solanum species and (ii) fungal or bacterial strains used, although interactions between accessions and Ralstonia solanacearum strains exist. Such interactions could explain why some results even refute the link between both resistances, such as those of [START_REF] Monma | Evaluation ofresistance to bacterial, Fusarium and Verticillium wilt in eggplant and eggplant-related species collected in Ghana[END_REF] who found al! their 53 S. aethiopicum accessions resistant to Fusarium wilt, being susceptible to BW.

Additional resistance to Verticillium wilt is described in the eggplant accession LS2436 [START_REF] Sakata | Evaluation of resistance to bacterial wilt and Verticillium wilt in eggplants (Solanum melongena L) collected in Malaysia[END_REF][START_REF] Saito | Development of Solanum melongena breeding fines as resistant rootstocks to Verticillium, Bacterial and Fusarium wilts[END_REF], as well as in some S. torvum accessions [START_REF] Narikawa | Collection of solanaceous plants in Malaysia and screening for disease resistance[END_REF], which resist to the three vascular diseases. lnterestingly in tomato, association within single genotypes (such as the famous Hawaii 7996) of resistance to three vascular diseases, bacterial wilt, bacterial canker and Fusarium wilt race 2 (in the absence of gene 1-2), has been noticed by Laterrot et al. (1978) and [START_REF] Laterrot | Resistance to Corynebacterium michiganense oflines bredfor resistance to pseudomonas solanacearum[END_REF].

Literature testifies that these «coincidences » (i.e. the resistance to two or three vascular diseases within a single gentotype) are not systematic, since they are found in a number of accessions only, and not in all accessions resistant to the one or the other of these disease resistance examples.

The summing up presented above explains why, intrigued by these occasional (but frequent enough to stick curiosity) association of resistances to two or more vascular diseases, within single genotypes in eggplant, related Solanum species as well as tomato, we further tested the hypothesis of a putative link between the resistance 1:0 bacterial and Fusarium wilt, on a range of eggplant germplasm. The synteny between the genomes of eggplant and tomato., and the growing knowledge of the genetic factors involved in the resistance to each ofthese diseases in both crops, provides a good background for unravelling in the future the possible genetic and functional similarities which could explain the presence in sorne accessions, of resistance to these two (or more) vascular diseases.

Screening of genetic resources

Material and methods

The INRA germplasm database was sorted out for identifying a sampling of S. melongena and related Solanum spp. accessions recorded as resistant to BW (Table 1). The behaviour « resistant » is a very « rough data », given bacterial wilt resistance is quantitative and depends on the bacterial strains tested. The information for resistance to BW originates either from INRA results obtained in the French West Indies, or from accessions donor, or from literature.

This material was tested to Fusarium oxysporum f. sp. melongenae. Susceptible controls were S. melongena Banaras Giant (MM 608) and Violette de Barbentane (LF3-24); Resistant controls were S. aethiopicum Aculeatum Group (MM 134) and S. sisymbriifolium (MM 284).The inoculation method is close to that used at INRA for tomato [START_REF] Moretti | Tests de résistance à 9 agents pathogènes chez la tomate[END_REF]. Inoculum was prepared by cultivating a Japanese Fusarium strain (TF 161), obtained , from Takii France, on an agitated synthetic culture medium, 8 days at 10 hours day/14h night and 18/23°C. At the time of inoculation, the solution was grinded and filtered. Two dilutions were used, one 1/5 1h in distilled water and 1/10 1h • Dilution 1/5!h matches 10 6 conidies/ml.

After sowing in pans, plantlets 18-21 days old were removed, roots are rinsed, partially eut, dipped into the inoculum for 5 mn and transplanted in new pans filled 2/3 compost, 1/3 sand (four accessions and one control -susceptible or resistant-per pan). Pans were then settled in a climatic chamber, regulated 12h/12h, 28°C constant. Twenty plants per genotype and per inoculum dilution were tested, given enough plantlets were available. Two weeks afer inoculation, symptoms were recorded on each plant as: resistant: no wilting, no vessels browing (or browning limited to hypocotyl), susceptible: wilting or no wilting, vessels browning present in the stem, further up cotyledons insertion.

Percentage of resistant plants was calculated as: 100 * [nurnber of resistant plants 1 20].

The test was repeated by Vilmorin in 2003, with two repeats of7 seven plants per accession. The percentage of resistant plants was calculated on the basis of two measurements, foliar wilting and vessels browing (scales n~t shown).

Results

The inoculurn dilution (l/5 th or l/loth), used in INRA screening test, did not affect the response of susceptible and resistant controls but sorne sligbt up or down variation of the proportion of susceptible and resistant plants was recorded for the .accessions tested (data not shown). For the sake of clarity, we present the INRA results ofboth clilutions merged together. Further, as there was a close link between the two measurernents used by Vilmorin -foliar wilting and vessels browing -(data not shown), we present only Vilrnorin results on the basis ofthe percentage ofresistant plants calculated from the vessels browning. Results are presented for the material subdivided into three categories. Figure 1 Resistant and susceptible controls behaved as expected, with almost 100% of plants respectiveley healthy or dead, for both series oftests. However, Vilmorin test was more stringent than INRA test, sin ce for all but a few accessions, the percentage of resistant plants is almost systematically lower (Figures 1,2,3).

The material bred at INRA for BW resistance (Figure 1), displays a variable behaviour towards Fusarium wilt, from fully susceptible (e.g. AG91-17, AG91-21, AG91-31) to a high levei ofresistance in INRA test (AG91-07, AG91-16), with all intermediate levels ofresistance between the extremes for the other accessions. For cases of resistance, resistance level is less than that of the resistant controls. For one accession only (AG91-15) the resistant behaviour is similar in both INRA and Vilmorin tests. ''''''

'1 . . 1 11 • • • •••• •••• "' " ""' ''* OK
The set of S. melongena accessions described as resistant to BW, is overall susceptible to Fusarium wilt, although MM 152 and MM 165 are moderately susceptible with sorne 50% plants resistant (Figure 2). -.-Interestingly, all S. aethiopicum tested and as weU as S. stramonifolium and one accession of S. violaceum (MM 497) are as resistant to Fusarium wilt as both resistant controls, S. sisymbriifolium and S. aethiopicum Aculeatum group. The few other accessions are moderately or slightly resistant (Figure 3).

Discussion and conclusion

Our experiments, carried out in 2002, suffer two limitations. First, they involve a material chosen on the basis of the (solely) rough/global information related to bacterial witt resistance, although resistance to BW is complex in terms of (i) interactions between resistance progenitors and bacterial strains [START_REF] Lebeau | Bacterial WiltResistance in Tomato, Pepper, andEggplant: Genetic Resources Respond to Diverse Strains in the Ralstonia solanacearum Species Complex[END_REF], (ii) of genetic controls (so far unravelled only for a very limited number of genotypes) as described in section 2, and (iii) of symptoms (unwilted plants can be severely colonized by the bacteria and environment changes can provoke their __ unexpected sudden wilting), Second, for the screening tests towards Fusarium wilt, we did not expect an heterogeneous behaviour within accessions, from one plant to another. This led to 'quantitative resistance levels (ranging between 0 and 100% resistant plants). Because of funding shortage, we could not check whether this heterogeneity was a matter of heterozygozity or of inoculum pressure.

Despite these limitations, our Fusarium wilt resistance screening tests of S melongena accessions and Solanum spp. accessions bred for resistance to BW, or described as resistant, indicate, in sorne cases, the existence of a genotype-dependant association between the resistances to both wilts. The cIoser association is found in accessions of S aethiopicum (Figure 3) as indicated by our results (9 accessions, described as resistant to BW, almost 100% resistant to Fusarium wilt) This association is found in the three cultigroups tested, Aculeatum (syn. S integrifolium), Gilo and Kumba. However, these results contradict those ofMonma et al. (1996) who found 100% of their 53 S aethiopicum accessions resistant to Fusarium witt, but susceptible to BW. These facts are cIues that (i) resistance to Fusarium wilt is Frequent in S 107 aethiopicum and (ii) that the resistant or susceptible behaviour of this species to BW depends on the bacterial strains used. Further, the Fusarium wilt results of [START_REF] Cappelli | Sources of resistance among Solanum spp. to an Italian iso/ate of Fusarium oxysporum jsp[END_REF], who found a 27 to 47% disease incidence in three accessions of S. aethiopicum, suggest that the resistance to Fusarium wilt of this species might be of a variable level, depending on the accessions. Interestingly, S. anguivi, the closest wild relative of S. aethiopicum, tested by [START_REF] Monma | Evaluation ofresistance to bacterial, Fusarium and Verticillium wilt in eggplant and eggplant-related species collected in Ghana[END_REF] (7 accessions), is also resistant to Fusarium wilt.. S. violaeeum, described as resistant to BW, is also almost 100% resistant to Fusarium wilt, but for one accession only (MM 497) out of the two tested. For the wild eggplant (MM 498) and S. virginianum (MM 265), both described as resistant to BW, the percentage of Fusarium resistant plants varies from almost 30% up to 60%.

The incidence of Fusarium wilt on S. melongena accessions known as BW resistant (Figure 2) is important, since they are either susceptible (most accessions) or of limited resistance for the best one (50% of resistant plants in MM 165, Sinampiro). Unfortunately, but because of unavailability, we did not test S. melongena LS2436 which is the sole S. melongena accession described in the literature as resistant to both wilts. This suggests that simultaneous resistance to both diseases might be rare within S. melongena germplasm.

The INRA AG-xx accessions (Figure 1), issued from complex crosses involving many progenitors including, for most ofthem, S. aethiopicum Aculeatum Group (MM 134), display a variable percentage of Fusarium wilt resistant plants, from null to higher than 90%. The available data do not allow to speculate far further from the hypothesis that the breeding program carried out at INRA Guadeloupe for BW resistance, has somehow, and more or less, « diluted » the Fusarium wilt resistance( s) of S. aethiopicum and/or of the possible Fusarium wilt resistance of the other BW resistant progenitors.

Our results do not invalidate but do not validate either the starting hypothesis ofthis paper, about a possible link between resistances to Fusarium and bacterial wilts. This link, if existing, at least in sorne genotypes of eggplant and relatives as well as in tomato, couid involve plant genes or QTLs involved in both resistances, or involve distinct genes inducing similar physiological reactions, or both. The existing synteny between both Solanaceous species, and the increasing knowledge of their genome provide tools for running cross search of the generalist ou pathogens-specific genes and mechanisms involved in controlling vascular diseases. Both diseases are vascular and induce the same kind of plant disorders, hence non specifie plant defenses Iirniting these disorders probably exist. The root system and what happens at the cotyledons insertion point seem to play a key role in limiting the development and upward spread of the vascular pathogens, once entered within the roots xylem vessels. Hence, given (i) the developping knowledge of the genetic controls to both diseases, and of the structure and expression of Fusarium (e.g. [START_REF] Barbierato | Phenotype and gene expression analyses of the Rfo-sa1 resistant aubergine interaction with Fusarium oxysporum j sp. melongenae and Verticillium dahliae[END_REF] and BW resistance genes (e.g. [START_REF] Reddya | Isolation, characterization and evolution of NBS-LRR encoding disease-resistance gene analogs in eggplant against bacterial will[END_REF], as well as (ii) the ongoing better management of Ralstonia solanaeearum strains (genotypes) used in resistance tests, prornising studies are expected in a near future, aiming at a better understanding of the specifie and/or common physiological and genetic mechanisms controlling the resistance to vascular wilts, including Fusarium and bacterial wilts.

Authors are thanliful to Dr Ph. Prior (INRA-CIRAD, La Réunion) for reviewing this paper .

.

Figure 1 .

 1 Figure 1. Percentage of plants resistant ta Fusarlum wilt (mate rial bred at INRA Guadeloupe for bacterlal wilt resistance)

Figure 2 .

 2 Figure 2. Percentage of plants resistant to Fusarium wilt (5. melongena accessions described as resistant to bacterial wilt)

Figure 3 .

 3 Figure 3. Percentageof plants reslstantto Fusarlum wllt (Solanum spp. accessions descrlbed as resistant to baderlal wilt)

Table 1 :

 1 is focused on AG-xx accessions, issued from BW breeding prograrns carried out at INRA Guadeloupe. Figure2is focused on accessions .of INRA S melongena collection described as resistant to BW. Figure3displays the results for a set of Solanum spp. also described as resistant to BW. AU histograms display tbe results for both INRA and Vilmorin tests. For each accession tested, the left, dark grey, bar illustrates INRA results, and the right one, light grey, Vilmorin results. List of the eggplant germplasm resistant ta bacterial wilt, tested for Fusarium witt

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