甘薯若干数量性状遗传参数和高淀粉高产育种策略研讨

根据4×6的NCⅡ交配设计，对甘薯淀粉产量、干物产量、淀粉率、干物率、鲜薯重等12个数量性状进行了配合力遗传效应分析，并对遗传力、亲子相关、回归和群体遗传变异系数等参数进行了估算。结果表明，所研究数量性状除结薯数外均以一般配合力遗传方差（Vgca）大于特殊配合力遗传方差（Vsca），但其在遗传总方差中的相对重要性因性状而颇有差异。亲子相关和回归系数的估值与广义遗传力在趋势上基本一致。淀粉率组合均值和F#-1高淀粉个体分布频率与中亲值密切正相关。由于育种群体中鲜薯重的遗传变异系数大于淀粉率并对淀粉产量具有更直接的正向线性效应，因此今后甘薯高淀粉高产育种应更有赖于对鲜薯重遗传潜力的开拓和利用。

GENETIC PARAMETERS OF QUANTITATIVE TRAITS AND BREEDING STRATEGY FOR HIGH STARCH CONTENT AND HIGH YIELD IN SWEET POTATO

Combining ability test employing NCII method was carried out in1985 when4 Chinese varieties were used as female and 6 foreign varieties as the male. Variance analysis of combining ability showed that the value of Vgca was greater than that of Vsca in 12 quantitative traits with the exception of no. roots in which Vsca was more superior than Vgca There were great differences among those traits on the Vgca % accounted of the total genetic variance. For example, no. root 14.76%,internode length 52.72%, fresh root wt. 57.62%, top wt. 57.65%, dry matter yield 60.56%. starch content 61.20%, per root wt.81.66%, no. of branches 97.34%.The heritability, coefficient of correlation and regression on Parent-offspring, and GCV in population for 12 traits were also estimated.The coefficient of genetic variation GCV for freshroot wt.(19.53%)was more larger than that of starch content (10.56%) with more significant positive effects on starch yield. Therefore, it was considered that to develop the breeding for high starch content and high yield of sweet pdtato we should pay more attention to creation and utilization of the genetic potentiality for fresh root wt. on the basis of certain starch content.