Abstract

GILLI, Javier Ramón; VELLICCE, Gabriel Ricardo  and  BERNARDI, Clarisa Noelia. SSR markers linked to stem canker resistance in soybean (Glycine max). Rev. Fac. Cienc. Agrar., Univ. Nac. Cuyo [online]. 2020, vol.52, n.1, pp.26-39. ISSN 1853-8665.

This work studied 40 samples of Diaporthe phaseolorum var. meridionalis (Dpm), causal agent of stem canker in soybeans (SCS). In the susceptible genotype Golondrina65, the isolate RSF12 showed the highest percentage of dead plant index (DP = 85.7 %) and was used to characterize all known sources of resistance to Dpm. The soybean MJ19RR experimental line showed, the best behaviour against this isolate with a DP = 2.4 % and was used to develop a segregating population with the susceptible cultivar FT-2001. In the F2 generation, a chi-square test determined a 3:1 ratio of resistant plants against susceptible plants, as expected for a dominant gene. In order to advance in our study, we proposed as objective, to map the resistance to Diaporthe phaseolorum var. meridionalis. The Bulked Segregant Analyses and the genetic linkage study identified a region on chromosome 6 of the genetic map of soybean, located at 13.3 cM from the Satt433 locus associated with resistance to SCS. The soybean experimental line MJ19RR was selected as the best source of resistance, available in the active bank of soybean germplasm of INTA, for the genetic control of this disease. The results obtained in this work represent a first approximation for the understanding of the genetic basis of resistance to SCS.

Keywords : Diaporthe phaseolorum var. meridionalis; Molecular markers; Fungal resistance; Glycine max.

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