摘要
Seed size and composition are important traits in food crops and can be affected by nutrient availability in the soil. Phosphorus （P） is a non-renewable, essential macronutrient, and P deficiency limits soybean （G1ycine max） yield and quality. To investigate the associations of seed traits in low- and high-P environ- ments, soybean recombinant inbred lines （RILs） from a cross of cultivars Fiskeby III and Mandarin （Ottawa） were grown under contrasting P availability environments. Traits including individual seed weight, seed number, and intact mature pod weight were significantly affected by soil P levels and showed transgressive segregation among the RILs. Surprisingly, P treatments did not affect seed composition or weight, suggesting that soybeanmaintains sufficient P in seeds even in Iow-P soil. Quantitative trait loci （QTLs） were detected for seed weight, intact pods, seed volume, and seed protein, with five significant QTLs identified in Iow-P environments and one significant QTL found in the optimaI-P environment. Broad-sense heritability estimates were 0.78 （individual seed weight）, o.go （seed protein）, 0.34 （seed oil）, and 0.98 （seed number）. The QTLs identified under low P point to genetic regions that may be useful to improve soybean performance under limiting P conditions.
Seed size and composition are important traits in food crops and can be affected by nutrient availability in the soil. Phosphorus （P） is a non-renewable, essential macronutrient, and P deficiency limits soybean （G1ycine max） yield and quality. To investigate the associations of seed traits in low- and high-P environ- ments, soybean recombinant inbred lines （RILs） from a cross of cultivars Fiskeby III and Mandarin （Ottawa） were grown under contrasting P availability environments. Traits including individual seed weight, seed number, and intact mature pod weight were significantly affected by soil P levels and showed transgressive segregation among the RILs. Surprisingly, P treatments did not affect seed composition or weight, suggesting that soybeanmaintains sufficient P in seeds even in Iow-P soil. Quantitative trait loci （QTLs） were detected for seed weight, intact pods, seed volume, and seed protein, with five significant QTLs identified in Iow-P environments and one significant QTL found in the optimaI-P environment. Broad-sense heritability estimates were 0.78 （individual seed weight）, o.go （seed protein）, 0.34 （seed oil）, and 0.98 （seed number）. The QTLs identified under low P point to genetic regions that may be useful to improve soybean performance under limiting P conditions.
基金
supported by the National Science Foundation grants IOS-1031416 and IOS-1444456
sabbatical leave funding from the Florida Agricultural and Mechanical University
