Nodulation and SSR markers to evaluate the BNF potential of Argentinean Cultivars of Soybean (Glycine max L. Merr)

PEDRO ALBERTO BALATTI, DARIO SALVUCCI, MONICA AULICINO, MARIANGELA HUNGRIA

Christopher S. Bond Life Sciences Center University of Missouri- Columbia, MO USA

Conferencia; The 21st North American Symbiotic Nitrogen Fixation Conference; 2010

Soybean is a crop that has high demands of N, part of it can be provided by biological nitrogen fixation. The purpose of this research was to evaluate the nodulation capacity of Argentinean soybean cultivars and the presence, in their genomes, of SSR linked to nodulation. Fifteen commercial cultivars (Nidera Semillas) were inoculated with Bradyrhizobium japonicum SEMIA-5079 and SEMIA-5080 and grown under controlled conditions for 35 days. Nodule number (NN), nodule dry weight (NDW) and shoot dry weight (SDW) was measured. 11 SSR primers (Cregan et al, 1999) were used to amplify microsatellites (Nicolás et al.,1999) from the 15 Argentinean cultivars. The cultivars proved to differ in their nodulation capacity, three clear phenotypic classes were identified high, medium and low nodulation ones. Two matrices: an allele frequency x phenotypic classes one and a presence absence of SSR alleles per cultivar were used to perform a Correspondence Analysis (CA) and a Cluster Analysis, respectively. A phenogram was built with simple matching coefficient and the unweighted pair group method.The phenogram grouped cultivars in five clusters with a similarity genetic value lower than 67%. CA confirmed the association between some SSR alleles and nodulation phenotypes, which allowed us to select the parental genotypes to make crosses for further evaluation of QTLs associated with nodulation capacity