大豆根系性状和磷效率的遗传规律研究

GENETIC ANALYSIS OF ROOT CHARACTRS AND THEIR RELATION TO PHOSPHORUS EFFLCIENCY IN SOYBEAN

选用两个磷效率差异明显的大豆品种,在营养液(磷浓度为0,50μM KH2PO4)和田间(土壤有效磷含量26 mg/kg)进行根系性状的遗传研究。结果表明:两个基因型的根系性状存在显著差异,F1代的总根长和磷效率都表现出明显的超亲优势,其超亲优势率分别为68%和56%;这些性状F2代的为连续变异,表现出多基因控制的特征,且都存在明显的超亲分离个体。遗传模型分析结果表明,这些性状一般都为两对主基因加多个微效基因控制,而且除根平均直径外(水培中无主基因存在),总根长和根体积的遗传模型在大田和短期营养液条件下基本一致。产量及生物产量与总根长、总表面积、平均直径、根体积和磷效率都呈极显著正相关,表明通过这两个性状也可以对根系和磷效率进行间接选择。大田试验各根系性状和磷吸收效率的遗传力都较高,因此在育种过程中对这些性状进行早代选择是可行的。

In this study, two contrasting soybean genotypes BD2 and BX10 from Guangdong and Brazil were used and a cross between them was made to produce F1, F2 progenies. The inheritance of soybean root traits and relationship between the root and other traits were investigate by the experiments of nutrient solution and soil cultivation. The results showed that there were significant differences in most root traits between the two genotypes. Both of the total root length and P efficiency of F1 showed significant over-parent heterosis and the value was 68% and 56% respectively. The distribution of these traits in F2 were all continuous and seemed to controlled by multi-genes. Moreover, over-parent segregates were observed for the traits. Further study indicated that most of the traits were controlled by two pair of major genes together with other multi-genes. Except average root diameter （ absent of major gene in solution culture）, the genetic model of the total root length, surface area and volume in soil cultivation were coincident with those in solution culture. Correlation analysis reveals that indirect are possible for root traits and P efficiency due to positive correlation between root traits and yield and biomass. Furthermore, because the heritabilities of most root traits is high in soil cultivation so it is feasible to carry out progeny selection in breeding programs.