SSR and AFLP based genetic diversity of soybean germplasm differing in photoperiod sensitivity

Forty-four soybean genotypes with different photoperiod response were selected after screening of 1000 soybean accessions under artificial condition and were profiled using 40 SSR and 5 AFLP primer pairs. The average polymorphism information content (PIC) for SSR and AFLP marker systems was 0.507 and 0.120, respectively. Clustering of genotypes was done using UPGMA method for SSR and AFLP and correlation was 0.337 and 0.504, respectively. Mantel's correlation coefficients between Jaccard's similarity coefficient and the cophenetic values were fairly high in both the marker systems (SSR = 0.924; AFLP = 0.958) indicating very good fit for the clustering pattern. UPGMA based cluster analysis classified soybean genotypes into four major groups with fairly moderate bootstrap support. These major clusters corresponded with the photoperiod response and place of origin. The results indicate that the photoperiod insensitive genotypes, 11/2/1939 (EC 325097) and MACS 330 would be better choice for broadening the genetic base of soybean for this trait

AFLP analysis of the phenetic organization and genetic diversity existing in the Saccharum complex

Author for correspondence (e-mail: [email protected])International audienceAmplified fragment length polymorphism (AFLP) markers were evaluated for determining the phylogenetic relationships, and the diversity in the Saccharum complex using 30 clones belonging to S. oficinarum, S. robustum, S. spontaneum, S. barberi, S. sinense and the related genus Erianthus. The phenetic tree of the species clones based on AFLP data was consistent with the known taxonomical relationships. AFLP gave higher resolution of closely related species into discrete groups than that by RAPD and RFLP markers, reported earlier. The levels of diversity within the various Saccharum species were also found to be higher than those obtained previously with the same set of clones using RAPD markers. The intraspecies similarity in S. barberi and S. sinense was much higher than interspecies similarity suggesting a clear separation of the two, which are considered ‘horticultural species’. The genetic similarity matrix derived from a single primer combination highly correlated (r = 0.980) with that obtained from all the 12 primer combination used in the study, thus highlighting the efficiency of a single primer combination in delineating species relationships. All the primer combinations could identify markers that are specific to each of the species and the genus Erianthus. Among the species, specific markers were highest in S. spontaneum followed by S. robustum, S. barberi, S. oficinarum and S. sinense. Erianthus had a distinct profile with 30% of the total amplified fragments being specific to it. This ofiers great scope for identifying intergeneric hybrids, which has been very difficult using morphological traits and RAPD markers. High degree of correspondence between the results from the cluster analysis based on Jaccard’s similarity index, Neighbour Joining tree based on Sokal and Michener distance matrix and AFTD (Analyses Factorielle on Table of Distances) analysis clearly demonstrated that AFLP markers would be an appropriate tool in providing better information about the relationships among the species, estimation of diversity, and in revealing species and genus specific markers that could be directly applied in sugarcane breeding programme