Introgression of resistance to Columbia and Northern root-knot nematodes fromSolanum bulbocastanum into cultivated potato

Summary Resistance toMeliodogyne chitwoodi races 1 (MC1) and 2 (MC2) andM. hapla (MH) derived fromSolanum bulbocastanum was introduced into the cultivated potato gene pool through somatic fusion. The initial F₁ hybrids showed resistance to the three nematodes. Resistance to reproduction on roots by MC1 was accompanied by resistance to tuber damage in F₁ clones. Tuber damage sometimes occurred, however, in hybrids of BC₁ progeny resistant to reproduction on roots when MC2 and MH were the challenging nematodes. Resistance to reproduction was transferred into BC₁ individuals, but a greater proportion of BC₁ progeny was resistant to MC1 than to MC2 or MH. Resistance to MC1 appears to be dominant and discretely inherited. F₁ and BC₁ progeny were pollen sterile, but seed were produced from crosses using cultivated tetraploid pollen sources. Approximately 11 and 33 per cent of pollinations produced berries on F₁ and BC₁ pistillate parents, respectively. Seed yield increased fourfold overall in crosses with F₁ compared to BC₁ individuals.Abbreviations MC1 Meloidogyne chitwoodi race 1 - MC2 Meloidogyne chitwoodi race 2 - MH Meloidogyne hapla - Rf Reproductive factor     

Screening and selection of eggplant and wild related species for resistance to <Emphasis Type="Italic">Leveillula taurica</Emphasis>

Screening for resistance to powdery mildew of Solanum melongena and wild related species was made in the field under natural infection conditions. A total of 172 accessions originating from several geographical parts of the world were tested. Single plant selection for resistance was carried out and open-pollination was used. Most S. melongena accessions were susceptible or highly susceptible to the disease. By S₀ to S₃ selection, an increase in the overall powdery mildew resistance level of S. melongena population was obtained and four S. melongena lines possessing a high level of resistance were obtained. Among the wild Solanum species, S. laciniatum and S. nigrum showed to be non-host plants of L. taurica. S. quinquangolare showed no symptoms of powdery mildew, S. linnaeanum, S. aculeatissimum, S. aviculare, S. pseudocapsicum were highly resistant, S. spinosissimum was resistant, S. gilo, S. capsicoides were susceptible or highly susceptible, and plants of S. sisymbriifolium showed a widely variable disease reaction. Four S. melongena resistant lines were obtained: PAVEG 10187 S₃, PAVEG 10196 S₃, P.I. 230279 S₃ and P.I. 419198 S₃. These S. melongena lines together with the resistant wild species could be used for genetic studies, classical breeding programs and biotechnological applications.     

Identification of somatic hybrids of dihaploid Solanum tuberosum lines and S. brevidens by species specific RAPD patterns and assessment of disease resistance of the hybrids

Summary Symmetric somatic hybrids were produced by electrofusion of protoplasts of two dihaploid tuber-bearing potato (Solanum tuberosum L.) lines and Solanum brevidens Phil., a diploid non-tuber-bearing wild potato species. A total of 985 plants was obtained. Verification of nuclear hybridity of putative hybrids was based on additive RAPD patterns, general morphological characteristics and chromosome counts. 53 (90%) calli regenerated into plants which were identified as somatic hybrids. Most of the hybrids were aneuploids at the tetraploid (4×) or hexaploid (6×) level. The 20 hybrids tested expressed a high level of resistance to potato virus Y (PVY ^N ) characteristic of the S. brevidens parent. Resistance to late blight (Phytophthora infestans (Mont.) de Bary) varied between hybrids, but was on average better than that of the fusion parents. Resistance of hybrids to bacterial stem rot (Erwinia carotovora subsp. atroseptica (van Hall) Dye) was not superior to that of commercial potato cultivars.     

Insect resistance in potatoes: sources,evolutionary relationships,morphological and chemical defenses,and ecogeographical associations

Summary The past 25 years, 1686 potato accessions, representing 100 species in the genus Solanum L., subgenus Potatoe, section Petota, were evaluated for field resistance to one or more of the following insect pests: green peach aphid, Myzus persicae (Sulzer); potato aphid, Macrosiphum euphorbiae (Thomas); Colorado potato beetle, Leptinotarsa decemlineata (Say); potato flea beetle, Epitrix cucumeris (Harris); and potato leafhopper, Empoasca fabae (Harris). Accessions highly resistant to green peach aphid were identified within 36 species, to potato aphid within 24 species, to Colorado potato beetle within 10 species, to potato flea beetle within 25 species, and to potato leafhopper within 39 species. Resistance levels were characteristic within Solanum species. Insect resistance appears to be a primitive trait in wild potatoes. Susceptibility was most common in the primitive and cultivated Tuberosa. Insect resistance was also characteristic of the most advanced species. The glycoalkaloid tomatine was associated with field resistance to Colorado potato beetle and potato leafhopper. Other glycoalkaloids were not associated with field resistance at the species level. Dense hairs were associated with resistance to green peach aphid, potato flea beetle, and potato leafhopper. Glandular trichomes were associated with field resistance to Colorado potato beetle, potato flea beetle, and potato leafhopper. Significant correlations between insect score and altitude of original collection were observed in six of thirteen species. Species from hot and arid areas were associated with resistance to Colorado potato beetle, potato flea beetle, and potato leafhopper. Species from cool or moist areas tended to be resistant to potato aphid.Abbreviations EBN Endosperm Balance Number     

New sources of resistance of cowpea (Vigna unguiculata) toStriga gesnerioides,a parasitic angiosperm

Summary Thirty-seven accessions of cowpea and yard-long bean were assessed for resistance toStriga gesnerioides. Cowpea plants were grown using anin vitro method, then inoculated with young seedlings ofS. gesnerioides produced from seed from three West African countries. Resistance was assessed by comparing the number and size ofS. gesnerioides tubercles on these accessions with those on a known susceptible cowpea, cv. Blackeye. Two cowpea landraces, APL-1 and 87-2, were completely resistant toS. gesnerioides from Burkina Faso, Mali and Cameroon and partially resistant toS. gesnerioides from Niger. Complete resistance was expressed either as a hypersensitive response of infected root tissues or as a severely retarded development of successful infections. All other accessions, including three samples of yard-long bean were susceptible toS. gesnerioides. The original 87-2 plants segregated for resistance and susceptibility. However, uniformly resistant progeny were obtained by producing seed from vegetatively propagated clones of single resistant 87-2 plants. Resistance of APL-1 and 87-2 toS. gesnerioides was confirmed in pot and field trials. Neither of these cowpeas were resistant toAlectra vogelii. Varieties APL-1 and 87-2 provide additional sources of resistance to most races ofS. gesnerioides, including a newly discovered virulent race from Benin.Abbreviations ICRISAT International Crops Research Institute for the Semi-Arid Tropics - IITA International Institute of Tropical Agriculture - SAFGRAD Semi-Arid Food Grain Research and Development     

Successful hybridization of non-tuberous Solanum etuberosum Lind. and tuberbearing S. pinnatisectum Dun.

The results of extensive crosses between the non-tuberous species Solanum brevidens and S. etuberosum on the one hand and ten tuber-bearing Solanum species on the other are presented. Three crosses gave rise to viable progeny. Two progenies consisted of diploid plants only of the strictly self-incompatible species of the mother parent. One cross, viz. S. etuberosum × S. pinnatisectum, produced highly vigorous but fully male sterile F₁ hybrids.It is suggested that this hybrid together with those between the tomato, Lycopersicon esculentum, and S, pennellii and S. lycopersicoides constitute piers of a bridge between tomato and potato species which in the future might enable gene transfer between these two crops via their wild relatives. However, such idea has to be treated with all proper reserve.The production of this new hybrid is the first step in making accessible to potato breeding the valuable genes which have been detected in S. brevidens and S. etuberosum, viz. the genes for high resistance to frost, leafroll and Y-virus.     

Evaluation of resistance to verticillium wilt in diploid,wild potato interspecific hybrids

Summary Verticillium wilt (V. albo-atrum Reinke & Berthold or V. dahliae Kleb) threatens potato (Solanum tuberosum L.) production in most growing areas of the world. Genetic resistance offers the most cost-effective and environmentally-sound control measure. However, there is a dearth of genetic and breeding information on resistance to verticillium wilt in potato, because of obscure parentage of some standard cultivars and the complex segregation at the tetraploid level. The wide range of genetic variability in wild relatives of potatoes can be potentially useful as a source of disease resistance, such as verticillium wilt resistance. Six diploid, wild, interspecific Solanum hybrids involving resistant x resistant and susceptible x resistant crosses, were assayed for verticillium wilt resistance under greenhouse conditions to evaluate their potential as sources of verticillium wilt resistance. The cross between S. gourlayi Oka. and S. chacoense Bitt. and its reciprocal had the most resistant progenies based on mean colony counts. No simple mode of inheritance can be proposed based on the observed segregation ratios. However, the continuous distributions observed on verticillium wilt disease response among hybrid families indicate that inheritance of resistance may be polygenic and complex. In addition, skewness of colony count distributions toward the resistance parents were characteristic of all resistant x susceptible crosses suggesting that resistance may be dominant. By contrast, the susceptible x susceptible cross showed a more normal distribution. Overall, the cross between S. gourlayi and S. chacoense showed the most potential as a source of verticillium wilt resistance.     

Bolivia potato germplasm collecting expeditions 1993, 1994: Taxonomy and new germplasm resources

Summary We conducted joint Bolivia/The Netherlands/United States wild potato (Solanum sect. Petota Dumort.) germplasm collecting expeditions in Bolivia from February 1-April 15, 1993, and January 1-February 26, 1994. The goals of the expeditions were to collect germplasm and gather data for continuing taxonomic studies of the approximately 43 taxa of Bolivian wild potatoes accepted by current taxonomists. We made 223 collections, 135 as true seed collections, 54 as tubers, 19 only as herbarium collections. Two recent taxonomic treatments of Bolivian wild and cultivated potatoes have clarified the taxonomy and distribution of these plants, but there are continuing disagreements between treatments regarding species boundaries and interrelationships. These disagreements, and the variability we observed in natural populations, present problems for identifications. We summarize the state of germplasm collections for Bolivia, provide our field data regarding the taxonomy of Bolivian wild potatoes, provide recommendations for future collecting, and provide new chromosome counts for S. hoopesii, S. ugentii, and S. yungasense.     

Reaction of tritordeum to Fusarium culmorum and Septoria nodorum

Summary Hordeum chilense is a wild barley extensively used in wide crosses in the Triticeae. It could be a valuable source of resistance to Fusarium culmorum and Septoria nodorum. Some H. chilense x Triticum spp. amphiploids, named tritordeums, were more resistant than the parental wheat line to these diseases, others were not. Average contents of ergosterol and deoxynivalenol (DON) suggested that resistance to colonization by Fusarium was the highest for Hordeum chilense, followed by tritordeum and wheat in decreasing order. In particular, the H. chilense genotypes H7 and H17 enhanced the wheat resistance to F. culmorum in its tritordeum offsprings. Resistance to S. nodorum in tritordeum was not associated with tall plant height. There is sufficient genetic variation for resistance to F. culmorum and S. nodorum among tritordeum to allow the breeding of lines combining short straw and resistance to both diseases.     

The breeding of the cultivated potato species solanum x juzepczukii and S. x curtilobum II. The resynthesis of S. x juzepczukii and S. x curtilobum

Summary The possibility of combining anew the genomes of wild and cultivated progenitors of triploid S. x juzepczukii and pentaploid S. x curtilobum by following the known evolutionary pathway of these species was investigated.The resynthesis of S. x juzepczukii was easy, and a wide range of synthetic forms was bred. Among these were forms with higher frost resistance (-5°C) than has been found in natural S. x juzepczukii. The total tuber glycoalkaloid content of several synthetic hybrids was lower than or as low as that of natural clones. Most synthetic hybrids were more vigorous than natural S. x juzepczukii and produced about the same types of tubers as are found in the natural range of variation. The best diploid parents were found in the species S. goniocalyx.The attempt to resynthesize pentaploid S. x curtilobum has not been successful but tetraploid plants were obtained in the process. An explanation for the occurrence of tetraploids resulting from triploid x tetraploid and/or diploid crosses is offered.The newly bred tetraploids contain at least one genome from S. acaule (possibly two) and hybridize easily with ssp. andigena. They thus provide a means for the transfer of S. acaule germ plasm into the tetraploid cultivated gene pool which would profit from the frost resistance of S. acaule.     

The sea beet source of resistance to multiple species of root-knot nematode

Development of commercially available host-plant resistance to Meloidogyne spp. is essential to sugarbeet (Beta vulgaris L.) root-knot nematode resistance breeding. Reactions of seedlings from resistant crosses and hybrid derivatives were evaluated against juvenile (J2) inoculations in the greenhouse. The noncultivated sea beet [B. vulgaris ssp. maritime (L.) Arcang] source of resistance is effective against the four economically important root-knot nematodes, i.e., M. incognita Races 1, 2 and 4 (Race 3 not tested), M. Javanica, M. arenaria Races 1 and 2, and M. hapla. In monoxenic culture, M. arenaria inoculations resulted in the most galling, and M. hapla, the least. Species combinations induced higher rates of infection. Different races of the same Meloidogyne species caused similar galling. Preliminary inoculation studies indicated that resistance was also effective to M. Chitwoodi and M. fallax. The trait of resistance to multiple Meloidogyne species may be valuable in developing sugarbeet, and possibly transgenic lines of other crops, resistant to root-knot nematode. This revised version was published online in July 2006 with corrections to the Cover Date.     

Interspecific hybrids between helianthus PetiolarisNutt. and H. Annuus L.: Effect of backcrossing on meiosis

Summary Interspecific substitutions of the nucleus of Helianthus annuus (2n=34) into the cytoplasm of H. petiolaris (2n=34) were obtained by successive backcrossing using cultivated sunflower, H. annuus, as the recurrent pollen parent.Meiosis in the F₁ was characterized by multivalents, suggesting that 10 of the 34 chromosomes were heterozygous for chromosomal interchanges. An additional pair of chromosomes also contained a paracentric inversion. Continued backcrossing resulted in rapid elimination of the meiotic aberrations evident in the F₁. In the BC₁, 1 of 11 plants had normal meiosis and by the BC₂, only 13 of 54 plants had meiotic aberrations similar to those of the F₁. However, trisomic progeny (2n=35) were found in 3 of the 11 BC₁ plants and 20 of the 54 BC₂ plants. No meiotic aberrations were observed in BC₃ or BC₄ plants. Plants with indehiscent anthers, and considered to be male sterile (M.S.), first occurred in the BC₁ and, by the BC₂, 51 of 54 plants were M.S. All 19 BC₃ and 16 BC₄ plants were M.S. Preliminary investigations suggest that the pollen from such plants is sterile and that the sterility is cytoplasmic rather than genetic.Disc-flower measurements were a useful technique for selecting samples at the correct stage of microsporogenesis, but could not be used to distinguish between successive backcrosses.     

Sources of resistance to diseases of sugar beet in related Beta germplasm: II. Soil-borne diseases

Between 580 and 700 accessions of related cultivated and wild species of the genus Beta were assessed for resistance to four soil-borne diseases of sugar beet: two seedling damping-off diseases caused by the fungi Aphanomyces cochlioides and Pythium ultimum and two diseases of more mature plants, Rhizoctonia root and crown rot, caused by the fungus R. solani, and Rhizomania, caused by Beet necrotic yellow vein virus (BNYVV), a furovirus transmitted by the plasmodiophorid Polymyxa betae. Analysis of resistance data (assessed on an international standardised 1–9 scale of Resistance Scores) indicated that the highest levels of resistance ({RS} 2) to A. cochlioides and P. ultimum were to be found amongst accessions of the more distantly related sections Corollinae (93% of accessions tested) and Procumbentes (10%), respectively; although useful levels could also be found in the more closely related, and sexually compatible, section Beta (1–6%). Resistance to Rhizoctonia was also found in section Beta (5–7%), depending on whether field or glasshouse tests were used, but there was little evidence of generally high levels of resistance to Rhizomania among accessions of this section. None of the accessions of sections Corollinae and Procumbentes exhibited any notable resistance to Rhizoctonia. However, all sections Procumbentes and some sections Corollinae (4%) accessions were highly resistant to Rhizomania. Individuals with high levels of resistance to Rhizomania were identified from within some section Beta and Corollinae accessions, in which there was evidence of segregation.     

The effect of chromosome doubling on fertility,meiotic behaviour and crossability of Solanum etuberosum × S. pinnatisectum

Summary Doubling the chromosome number of sterile F₁ hybrids of S. etuberosum × S. pinnatisectum resulted in fertile allotetraploid hybrids (code 4x-EP) with nearly normal chromosome pairing at meiosis. Many seeds were obtained from selfing and sibbing, but seed set varied considerably. The 4x-EP hybrids were successfully crosses as females with S. stoloniferum and S. polytrichon and as males with S. verrucosum. The crosses with S. stoloniferum and S. polytrichon were carried out reciprocally and unilateral incompatibility was detected. Crosses of 4x-EP hybrids as males onto S. phureja and S. tuberosum cv. Gineke produced parthenocarpic berries only. Nearly 1700 flowers of colchicine-doubled S. pinnatisectum × S. bulbocastanum and the trispecific hybrid (S. acaule × S. bulbocastanum) × S. phureja did not yield a single berry after pollination with a pollen mixture from 20 4x-EP plants.It is concluded that the use of the bridging species S. pinnatisectum and either S. stoloniferum, S. polytrichon or S. verrucosum may enable gene transfer from the non-tuberous Etuberosa species to potato cultivars.     

Brassilexin accumulation and resistance to Leptosphaeria maculans in Brassica spp. and progeny of an interspecific cross B. juncea × B. napus

Summary Resistance to Leptosphaeria maculans was assessed in Brassica napus, B. juncea, B. carinata, B. nigra and progeny issuing from an interspecific cross B. napus × B. juncea, using a cotyledon-inoculation test. In these individual plants, brassilexin accumulation was determined following an abiotic, non-specific, elicitation. All the tested B. napus cultivars were highly susceptible to the parasite and weakly accumulated brassilexin. In contrast, B. juncea, B. carinata, and B. nigra usually displayed a hypersensitive response to the inoculation and accumulated more brassilexin than B. napus. The same correlation between resistance to L. maculans and phytoalexin accumulation was observed in the interspecific hybrid progeny. The cotyledon-inoculation test allowed the discrimination of plants displaying a hypersensitive response to the inoculation from those highly sensitive to the parasite, but intermediate disease severity classes were not usually representative of resistance or susceptibility. In this respect, brassilexin determination allowed differentiation, within a set of plants presenting an intermediate response to the pathogen, of plants with a high (B. juncea-like), and with a weak (B. napus-like) ability to accumulate brassilexin.Abbreviations IHP interspecific hybrid progeny - JR B. juncea-type complete resistance to blackleg (Roy, 1984) - W&D test cotyledon-inoculation test as described by Williams & Delwiche (1979)     

Sources of resistance to diseases of sugar beet in related <Emphasis Type="Italic">Beta</Emphasis> germplasm: I. Foliar diseases

Resistance to four foliar diseases of sugar beet (Beta vulgaris ssp. vulgaris), virus yellows caused by Beet mild yellowing virus (BMYV) and Beet yellows virus (BYV), powdery mildew (Erysiphe betae) and Cercospora leaf spot (Cercospora beticola), was assessed in up to 600 accessions of closely related wild and cultivated Beta species. Most accessions were from the Section Beta, a taxon containing types most closely related to, and sexually compatible with, sugar beet and therefore most valuable for use in crop improvement. Between 1–12% of accessions were highly resistant (resistance scores of 2 on an international standardised resistance scale of 1–9) to these diseases. These levels, however, underestimate the potential number of resistant sources available from this section as some accessions with intermediate mean resistance scores contained a significant proportion of highly resistant plants within segregating populations. Variation in resistance to all diseases except BYV was observed within the Section Beta. Much higher levels of resistance were observed, and more frequently, in more distantly related sections of the genus Beta. Accessions of the Section Corollinae were highly resistant to both viruses (>62% of accessions tested), but less so to Cercospora (15%) and they were very susceptible to powdery mildew. Section Procumbentes accessions were highly resistant to BMYV and Cercospora (100%) but less so to powdery mildew (50%) and BYV (20%). However, sexual incompatibility between these sections and sugar beet make utilisation of these sources impractical using conventional breeding methods.     

Immunity to Clavibacter michiganensis subsp. sepedonicus: Screening of exotic Solanum species

Summary Accessions from exotic Solanum species, including diploid and tetraploid species, were screened for immunity to Clavibacter michiganensis subsp. sepedonicus, the causal agent of potato ring rot. The diploid species included S. infundibuliforme, S. lesteri, S. megistacrolobum, S. tuberosum Group Phureja, S. polyadenium, S. pinnatisectum, S. raphanifolium, S. sparsipilum, S. sanctae-rosae, S. tuberosum Group Stenotomum, S. toralapanum, and S. verrucosum. The tetraploid species included S. tuberosum Group Andigena, S. acaule, S. fendleri, S. hjertingii, S. oplocense, S. polytrichon, and S. stoloniferum. Apparent immunity was initially found in several diploid species, but was not present during subsequent retesting. Immunity was found in nine accessions of tetraploid S. acaule. These accessions maintained their immunity during testing over an eight-month period. S. acaule appears to be a good source of immunity for introgression studies.     

Breaking the crossability barriers between disomic tetraploid Solanum acaule and tetrasomic tetraploid S. tuberosum

Summary A combination of compatible second pollinations and embryo rescue was applied for systematic production of true tetraploid hybrids from crosses between disomic tetraploid Solanum acaule and tetrasomic tetraploid potato, S. tuberosum. Several genotypes of tetraploid potatoes were pollinated with S. acaule, and the compatible second pollinations were made on the following day, with a genotype of S. phureja, IvP 35 to promote fruit development. Embryo rescue was carried out in 21 families, 14 to 27 days after the first pollination. A total of eight plants were obtained from the embryo rescue and their chromosome numbers were counted in the root tips. Three of the eight plants were identified as tetraploid, and five others as diploid. Morphology, isozyme banding patterns, and pollen stainability, as well as potato spindle tuber viroid (PSTVd) resistance, indicated the hybrid nature of the three plants. This is the first report of successful tetraploid hybrid production between disomic tetraploid S. acaule (4x) and tetrasomic tetraploid potatoes. Seed set from the crosses between one of hybrids and diploid potatoes indicated workable levels of both male and female fertility for introgression of valuable genes from S. acaule into the cultivated potato gene pool. The methodology used may be applied to other disomic tetraploid tuber-bearing Solanum species and with some modifications also to distantly related solanaceous species and genera.     

Molecular characterization of the progeny of <Emphasis Type="Italic">Solanum etuberosum</Emphasis> identifies a genomic region associated with resistance to potato leafroll virus

Potato leafroll virus (PLRV; Genus Polerovirus; Family Luteoviridae) is one of the most important virus pathogens of potato worldwide and breeders are looking for new sources of resistance. Solanum etuberosum Lindl., a wild potato species native to Chile, was identified as having resistances to PLRV, potato virus Y, potato virus X, and green peach aphid. Barriers to sexual hybridization between S. etuberosum and cultivated potato were overcome through somatic hybridization. Resistance to PLRV has been identified in the BC₁, BC₂ and BC₃ progeny of the somatic hybrids of S. etuberosum (+) S. tuberosum haploid × S. berthaultii Hawkes. In this study, RFLP markers previously mapped in potato, tomato or populations derived from S. palustre (syn S. brevidens) × S. etuberosum and simple sequence repeat (SSR) markers developed from tomato and potato EST sequences were used to characterize S. etuberosum genomic regions associated with resistance to PLRV. The RFLP marker TG443 from tomato linkage group 4 was found to segregate with PLRV resistance. This chromosome region has not previously been associated with PLRV resistance and therefore suggests a unique source of resistance. Synteny groups of molecular markers were constructed using information from published genetic linkage maps of potato, tomato and S. palustre (syn. S. brevidens) × S. etuberosum. Analysis of synteny group transmission over generations confirmed the sequential loss of S. etuberosum chromosomes with each backcross to potato. Marker analyses provided evidence of recombination between the potato and S. etuberosum genomes and/or fragmentation of the S. etuberosum chromosomes.     

Distribution,ecology and reproductive biology of wild tomatoes and related nightshades from the Atacama Desert region of northern Chile

Over the past 20 years, several expeditions were made to northern Chile to collect populations of wild tomatoes (Solanum chilense, S. peruvianum) and allied nightshades (S. lycopersicoides, S. sitiens), and obtain information about their geographic distribution, ecology and reproductive biology. Restricted mainly to drainages of the Andean and the coastal cordillera, populations are geographically fragmented. The two nightshade species are rare and threatened by human activities. Adaptation to extreme aridity and soil salinity are evident in S. chilense and S. sitiens (the latter exhibits several xerophytic traits not seen in the tomatoes) and to low temperatures in S. lycopersicoides and S. chilense. All tested accessions are self-incompatible, with the exception of one S. peruvianum population collected at the southern limit of its distribution. Several distinguishing reproductive traits—anther color, attachment, and dehiscence, pollen size, and flower scent—suggest S. sitiens and S. lycopersicoides attract different pollinators than S. chilense and S. peruvianum. The four Solanum spp. native or endemic to Chile provide a variety of novel traits which, through hybridization and introgression with cultivated tomato, could facilitate development of improved varieties, as well as research on a variety of basic topics, including plant-pollinator interactions, abiotic stress responses, and evolution of reproductive barriers.