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Wild relatives of crops have the potential to improve food crops, especially in terms of improving abiotic stress tolerance. Two closely related wild species of the traditional East Asian legume crops, Azuki bean (Vigna angularis), V. riukiuensis "Tojinbaka" and V. nakashimae "Ukushima" were shown to have much higher levels of salt tolerance than azuki beans. To identify the genomic regions responsible for salt tolerance in "Tojinbaka" and "Ukushima", three interspecific hybrids were developed: (A) azuki bean cultivar "Kyoto Dainagon" × "Tojinbaka", (B) "Kyoto Dainagon" × "Ukushima" and (C) "Ukushima" × "Tojinbaka". Linkage maps were developed using SSR or restriction-site-associated DNA markers. There were three QTLs for "percentage of wilt leaves" in populations A, B and C, while populations A and B had three QTLs and population C had two QTLs for "days to wilt". In population C, four QTLs were detected for Na+ concentration in the primary leaf. Among the F2 individuals in population C, 24% showed higher salt tolerance than both wild parents, suggesting that the salt tolerance of azuki beans can be further improved by combining the QTL alleles of the two wild relatives. The marker information would facilitate the transfer of salt tolerance alleles from "Tojinbaka" and "Ukushima" to azuki beans. [ABSTRACT FROM AUTHOR]

In this study, genetic diversity and structure of 474 cultivated and 19 wild lablab (Lablab purpureus) accessions. were determined using 15 nuclear and 6 chloroplast SSR markers. The overall gene diversity was relatively low (0.3441). Gene diversity in the wild accessions (0.6059) was about two-folds greater than that in the cultivated accessions. In the wild accessions, gene diversity was greatest in the southern Africa, followed by East Africa. In the cultivated accessions, gene diversity was highest in the eastern Africa. The results suggested that South Africa is the center of origin and East Africa is the center of domestication of lablab. Different cluster analyses showed that 2-seeded-pod cultivated accessions (ssp. uncinatus) were clustered with wild accessions and that 4–(6)-seeded-pod cultivated accessions (ssp. purpureus and bengalensis) were intermingled. UPGMA tree suggested that ssp. purpureus and bengalensis were domesticated from 4-seeded-pod wild accessions of southern Africa. Haplotype network analysis based on nuclear SSRs revealed two domestication routes; the ssp. uncinatus is domesticated from 2-seeded-pod wild lablab (wild spp. uncinatus) from East Africa (Ethiopia), while the ssp. purpureus and bengalensis are domesticated from 4-seeded-pod wild lablab from Central Africa (Rwanda). These results are useful for understanding domestication and revising classification of lablab. [ABSTRACT FROM AUTHOR]

Introduction Yardlong bean (Vigna unguiculata (L.) Walp. subsp. unguiculata Sesquipedalis Group) (2n = 2x = 22) is one of the most important vegetable legumes of Southeast and East Asia. It [...], Yardlong bean (Vigna unguiculata (L.) Walp. subsp. unguiculata Sesquipedalis Group) (2n = 2x = 22) is one of the most important vegetable legumes of Asia. The objectives of this study were to develop a genetic linkage map of yardlong bean using SSR makers from related Vigna species and to identify QTLs for pod length. The map was constructed from 226 simple sequence repeat (SSR) markers from cowpea (Vigna unguiculata (L.) Walp. subsp. unguiculata Unguiculata Group), azuki bean (Vigna angularis (Willd.) Ohwi & Ohashi), and mungbean (Vigna radiata (L.) Wilczek) in a [BC.sub.1][F.sub.1] ((JP81610 x TVnu457) x JP81610) population derived from the cross between yardlong bean accession JP81610 and wild cowpea (Vigna unguiculata subsp. unguiculata var. spontanea) accession TVnu457. The markers were clustered into 11 linkage groups (LGs) spanning 852.4 cM in total length with a mean distance between adjacent markers of 3.96 cM. All markers on LG11 showed segregation distortion towards the homozygous yardlong bean JP81610 genotype. The markers on LG11 were also distorted in the rice bean (Vigna umbellata (Thunb.) Ohwi & Ohashi) map, suggesting the presence of common segregation distortion factors in Vigna species on this LG. One major and six minor QTLs were identified for pod length variation between yardlong bean and wild cowpea. Using flanking markers, six of the seven QTLs were confirmed in an [F.sub.2] population of JP81610 x TVnu457. The molecular linkage map developed and markers linked to pod length QTLs would be potentially useful for yardlong bean and cowpea breeding. Key words: cowpea, linkage map, microsatellite markers, Vigna unguiculata, yardlong bean. La dolique asperge (Vigna unguiculata (L.) Walp. subsp. unguiculata Sesquipedalis Group) (2n = 2x = 22) est l'une des legumineuses potageres les plus importantes en Asie. Les objectifs de ce travail etaient de developper une carte genetique de la dolique asperge en employant des marqueurs SSR provenant d'especes apparentees du genre Vigna et d'identifier des QTL pour la longueur de la gousse. La carte produite compte 226 marqueurs SSR provenant du niebe (Vigna unguiculata (L.) Walp. subsp. unguiculata Unguiculata Group), du haricot azuki (Vigna angularis (Willd.) Ohwi & Ohashi) et du haricot mungo (Vigna radiata (L.) Wilczek) au sein d'une population BC1F1 ((JP81610 x TVnu457) x JP81610) derivee d'un croisement entre l'accession JP81610 de la dolique asperge et l'accession TVnu457 du niebe sauvage (Vigna unguiculata subsp. unguiculata var. spontanea). Les marqueurs ont forme 11 groupes de liaison (LG) s'etendant sur 852,4 cM, pour une distance moyenne entre les marqueurs de 3,96 cM. Tous les marqueurs sur le LG11 presentaient un biais de segregation en faveur du genotype de la dolique asperge JP81610. Les marqueurs du LG11 presentaient egalement un biais au sein de la carte genetique du haricot riz (Vigna umbellata (Thunb.) Ohwi & Ohashi), ce qui suggere la presence partagee de facteurs causant la distorsion genetique chez les especes du genre Vigna sur ce groupe de liaison. Un QTL majeur et six QTL mineurs ont ete identifies pour expliquer la variation pour la longueur des gousses entre la dolique asperge et le niebe sauvage. A l'aide de marqueurs voisins, six des sept QTL ont ete confirmes au sein d'une population [F.sub.2] JP81610 x TVnu457. La carte genetique produite et les marqueurs lies a des QTL pour la longueur des gousses seront potentiellement utiles en amelioration genetique de la dolique asperge et du niebe. Mots-cles : niebe, carte genetique, marqueurs microsatellites, Vigna unguiculata, dolique asperge. [Traduit par la Redaction]