利用亲本间生物量、收获指数和产量有较大差异的南农1138-2和科丰1号杂交衍生的大豆重组自交家系(NJRIKY),研究始花期(R1)、始荚期(R3)、始粒期(R5)、收获期生物量以及表观收获指数和产量间的相关,并进行QTL定位,分析相关的遗传基础。结果表明,(1)生物量与产量显著相关,相关程度随生长进程逐渐增加,收获期生物量与产量相关最高,R^2=0.76。R1、R3、R5期生物量与产量的相关呈负指数曲线相关,生物量分别达到1000、2300和5500kghm^-2时,产量不再随生物量的增加而增加。收获期生物量与产量呈直线正相关,在试验范围内未发现高产的收获期生物量上限。表观收获指数与产量呈指数曲线相关,小于0.42时与产量具正变关系,大于0.42时与产量具负变关系。收获期生物量与表观收获指数呈指数曲线相关,表观收获指数增加生物量降低。(2)检测到产量、表观收获指数、收获期生物量有关的QTL分别为9、10和10个,其中两年稳定的QTL分别有2、3、3个。检测到R1、R3和R5期生物量有关的QTL分别有6、9和6个,其中3个时期在两年均能稳定表达的有2个。(3)在9个产量QTL中的6个区间,还同时检测到生物量和表观收获指数有关的QTL,该3性状有部分QTL共享同一连锁区间,表明有其共同的遗传基础,同时也解释了性状间相关的遗传原因。
Since soybean seed yield is the product of both biomass accumulation and harvest index, the objective of the present study was to measure the correlations of seed yield with the other two traits as well as with biomass accumulation at different seed development stages, to map their QTLs, and to reveal the QTL basis of the correlations. A RIL population, NJRIKY, derived from the cross between Nannong 1138-2 and Kefeng 1, quite diverse in biomass, harvest index and yield, was used to study the correlation among biomass accumulation, apparent harvest index and yield, to map the QTLs of the traits for revealing the genetic basis of the correlation among the traits. The results obtained were as follows: (1) Yield was closely and positively correlated with biomass accumulation and their correlation increased in the process of growth with the highest R^2=0.76 at harvest stage. There appeared some negative exponential correlation between yield and biomass at R1, R3, and R5, with the biomass of 1 000, 2 300, and 5 500 kg ha^-1 as the highest turning point, respectively. A linear correlation of yield with biomass at harvest stage [BM (H)] was detected, but without upper limit of the biomass found in the present experiment. There was an exponential correlation between yield and apparent harvest index, with 0.42 as the turning point, positive relationship as less than 0.42 and negative relationship as larger than 0.42. (2) 9, 10, and 10 QTLs for yield, apparent harvest index and BM (H) were detected in NJRIKY and 2, 3, and 3 QTLs of them respectively detected in both years. In addition, 6, 9, and 6 QTLs for biomass at R1, R3, and R5 were identified in the population, respectively, with 2 of them being detected across R1 through R5 in both years. (3) Among the 9 yield QTLs, 6 marker intervals were found to have QTLs conferring biomass and apparent harvest index, which implied a partially common genetic basis among the three traits.