大豆苗期耐低磷性及其QTL定位

利用来自波高和南农94-156（耐低磷种质）的重组自交系群体NJ(SP)BN（151个家系）通过盆栽试验研究与耐低磷有关的性状，并进行耐低磷性状的QTL定位。初步结果表明，不施磷处理的总干重主要由单株P吸收量决定，而与磷利用效率无关；而单株P吸收量与根干重、根效率均极显著正相关，单株P吸收量变异的76.2%由根效率决定。不施磷处理的根冠比（R/S）显著增加主要是茎干重无显著变化而根干重显著增加所致。在D1b+W、F、G、N和O等5个连锁群上共检测到7个QTL与耐低磷有关。分别可解释所对应性状表型变异的4.8%~17.0%，其中5个QTL的增效基因来自亲本波高，2个QTL的增效基因来自亲本南农94-156。

QTL Mapping of Phosphorus Deficiency Tolerance in Soybean (Glycine max L.) during Seedling Stage

Phosphorus(P) deficiency is a major abiotic stress that limits productivity of crops such as soybean throughout the world.In the present investigation,151 recombinant inbred line(RIL) families derived from a cross between Bogao and Nannong 94-156(low phosphorus tolerant germplasm) and their genetic maps were used to detect quantitative trait locus(QTL) associated with P deficiency tolerance by pot culture of soybean seedlings with two treatments of minus-P and plus-P.After six weeks of seeding,the relative total dry weight(RTDW),relative phosphorus uptake per plant(RPU),relative phosphorus use efficiency(RPUE),and relative root to shoot ratio(RR/S) were measured as indices for tolerance to phosphorus deficiency.The primary results showed that total dry weight under P-minus condition was determined by phosphorus uptake per plant,and no correlation between phosphorus use efficiency and total dry weight.Phosphorus uptake per plant was significantly and positively correlated with root dry weight and root efficiency(P uptake per unit weight of root),and 76.2% of variance of phosphorus uptake per plant came from root efficiency.Root/shoot ratio under P-minus condition was increased significantly because of no significant change of shoot dry weight and significant increase of root dry weight.Seven QTLs associated with phosphorus deficiency tolerance were detected and mapped on the linkage groups of D1b W,F,G,N,and O.Each QTL explained 4.8%-17.0% of phenotypic variance,positive alleles of five QTLs among them were from female parent 'Bogao',and those of the other QTLs from male parent 'Nannong 94-156'.Three of seven QTLs were mapped!on linkage group G,among them one major QTL for RTDW explained more than 10% of the phenotypic variance was detected between sat-203 and sat-185 on LG-G by using CIM and MIM methods.