Comparative genome analysis of mungbean (Vigna radiata L. Wilczek) and cowpea (V. unguiculata L. Walpers) using RFLP mapping data

Abstract

Genome relationships between mungbean (Vigna tradiata) and cowpea (V. Unguiculata) based on the linkage arrangement of random genomic restriction fragment length polymorphism (RFLP) markers have been investigated. A common set of probes derived from cowpea, common bean (Phaseolus vulgaris), mungbean, and soybean (Glycine max) PstI genomic libraries were used to construct the genetic linkage maps. In both species, a single F2 population from a cross between an improved cultivar and a putative wild progenitor species was used to follow the segregation of the RFLP markers. Approximately 90% of the probes hybridized to both mungbean and cowpea DNA, indicating a high degree of similarity in the nucleotide sequences among these species. A higher level of polymorphism was detected in the mungbean population (75.7%) than in the cowpea population (41.2%). Loci exhibiting duplications, null phenotypes, and distorted segregation ratios were detected in both populations. Random genomic DNA RFLP loci account for about 89% of the currently mapped markers with a few cDNA and RAPD markers added. The current mungbean map is comprised of 171 loci/loci clusters distributed in 14 linkage groups spanning a total of 1570cM. On the other hand, 97 markers covered 684 cM and defined 10 linkage groups in the current cowpea map. The mungbean and cowpea genomes were compared on the basis of the copy number and linkage arrangement of 53 markers mapped in common between the two species. Results indicate that nucleotide sequences are conserved, but variation in copy number were detected and several rearrangements in linkage orders appeared to have occurred since the divergence of the two species. Entire linkage groups were not conserved, but several large linkage blocks were maintained in both genomes.

Role of Genomic tools for Mungbean [Vigna radiata (L.) Wilczek] improvement

“…Marker orders and LGs were similar in both taxa with syntenic association appeared on 10 genomic regions although duplication and rearrangement exist (Menancio et al, 1993). Mungbean and azuki bean linkage maps share several conserved genome segments without or with some rearrangement (Kaga et al, 2000;Isemura et al, 2007) and showed that LG 1, 2, 3, 4, 8 and 11 of mungbean map (Menancio et al, 1993) correspond respectively to LG (1,4,10, 8, 2 and 9) of azuki bean map (Han et al, 2005). Genome conservation between mungbean and common bean appears to be higher than between mungbean and cowpea (Boutin et al, 1995) or azuki bean (Kaga et al, 2000).…”

“…trait loci, map-based cloning, and physical map construction. Now, F 2 or recombinant inbred lines (RILs populations) based six molecular linkage maps for mungbean have been published (Menancio et al, 1993;Boutin et al, 1995;Lambrides et al, 2000;Humphry et al, 2002). A Linkage map form mungbean population developed from inter subspecific crosses of VC 3980, cultivated x TC1966, wild from Madagascar and Berken, cultivated x ACC41, wild from Australia have been published using RFLP and RAPD markers.…”

Tagging and mapping of genes and QTL and molecular marker-assisted selection for traits of economic importance in bean and cowpea

“…Genetic maps of cowpea have been established by Fatokun et al (1992Fatokun et al ( , 1993, Menancio-Hautea et al (1993), Menéndez et al (1997), Ubi et al (2000) and Ouédraogo et al (2002). Of these, the latter, building on the earlier version developed by Menéndez et al (1997), is the most current and complete map and will be discussed in this article (http://pubs.nrc-cnrc.gc.ca/ cgi-bin/rp/rp2_abst_f?gen_g01-102_45_ns_nf_gen1-02).…”

Syntenic Relationships between Medicago truncatulaand Arabidopsis Reveal Extensive Divergence of Genome Organization,

“…The bestdocumented cases of genome conservation are from the grass family (Poaceae), where rice (Oryza sativa) with its small genome has been selected as a nodal species to study the economically important cereal crops including corn (Zea mays), sorghum (Sorghum bicolor), wheat (Triticum aestivum), and barley (Hordeum vulgare; Devos and Gale, 2000). Extensive macrosynteny has also been observed within the Solanaceae (Tanksley et al, 1992), the Brassicaceae (Kowalski et al, 1994;Lagercrantz and Lydiate, 1996;Lagercrantz, 1998;O'Neill and Bancroft, 2000;Acarkan et al, 2000), and the Fabaceae (Weeden et al, 1992;Menacio-Hautea et al, 1993;Torres et al, 1993;H.-K. Choi and D.R. Cook, unpublished data).…”