粳型杂种稻米品质性状的遗传表达

应用莫惠栋等新近提出的P十ｑ＋2Ｐｑ交配设计及其分析方法，分析了模型杂种９个品质性状的遗传表达，试验材料P＝４，ｑ＝７。结果表明：（１）糙米率、精米率、整精米率、粒长、粒宽和垩白率６个性状的遗传受母株基因型控制，它们在Ｆ２米粒间（着生在Ｆ１植株上）没有发生遗传分离，而糊化温度、直链淀粉含量和胶稠度３个性状在民米粒间有显著的遗传分离，因此主要受胚乳基因型控制。（２）除直链淀粉含量外，其余８个性状的遗传变异均以加性方差为主。在直链淀粉含量、糊化温度和胶稠度３个性状中，种子性状分离方差都占有较高比例，进一步证明了Ｆ２种子的这３个性状的遗传主要是由胚乳自身的基因型决定的。（３）正反交测验的结果表明，９个品质性状均存在显著的细胞质效应，但细胞质遗传方差仅占遗传总方差的２．４９％（糊化温度）～２９．３％（精米率），多数性状集中在２％与５％之间，所以品质性状的细胞质遗传效应在总体上是不大的，但在性状间存在差异。

Genetic Expression for Quality Traits of Rice Grain in Japonica Hybrids

A statistical method recently proposed by Mo et al. for analysing the inheritance of seed trait in p q Zpqmating design was used to investigate the genetic expression of nine quality traits in japonica hybrid rice. The parents were p= 4 maintainers and q = 7 restorers. The results showed: (1)The expression of brown, milled, and head rice rates (BRR,MRR, HRR), grain length (GL), grain width (GW), and chalkiness score(CS) in hybrids was subject to the diploid maternal genotypes and no genetic segregation occurred among F2 grains born on F1 plant. However, very significant segregationwas found among F2 grains in gelatinization temperature (GT), amylose content (AC), and gel consistency (GC). This indicated that the inheritance of GT, AC, and GC was mainly controlled under the endosperm genotype. (2) The additive variation was principal component in all traits except AC. But the variance due to F, grain segregation had a considerable share intotal genetic variance in AC, GT, and GC traits. This suggested further that the three traits were mainly controlled bytriploid endosperm genotyps. (3) The result of reciprocals showed there was a significant cytoplasmic effect in all nine qualitytraits, but their shares were not large, only from 2. 49% (GT) to 29. 3% (MRR) and concentrating from 2% to 5%. Although variation was also observed among traits or crosses.