Quantitative trait loci associated with soybean tolerance to low phosphorus stress based on flower and pod abscission

Abstract

With 2 figures and 5 tables AbstractLow phosphorus (P) stress limits soybean production. A population of 152 recombinant inbred lines (RILs) derived from a cross between ‘Bogao’ (P sensitive variety) and ‘Nannong 94‐156’ (P tolerant variety) and 248 markers were used to map quantitative trait loci (QTLs) for low‐P tolerance. Two pot culture trials were conducted and low‐P tolerance evaluated using flower and pod abscission rate under low P and normal P. Conditional QTLs and epistasis for tolerance to low P were also analysed. A conditional QTL (near Satt274) on linkage group D1b+W was identified which conferred low‐P tolerance epistatic effects and coincided with previously discovered QTLs. An additive QTL, qFARLPG‐07, for flower abscission rate under low P was detected with a LOD score of 7.79 and explained 32.3% of phenotypic variation. It was detected at the same interval of the corresponding QTL for other traits across years. This region coincided with two conditional QTLs (cqFARLPG‐07 and cqPARLPG‐07), from the P‐tolerant parent ‘Nannong 94‐156’ related to low‐P tolerance. These results will provide a basis for further fine mapping and eventual cloning of the P‐efficiency genes in soybean.