低温种植下水稻F_2群体生物学性状的遗传分析

Genetic Analysis of Biological Characteristics in Rice F_2 Populations Planted at Low Temperature

以耐冷性极强的粳稻老品种小麻谷与具有籼稻细胞质背景的改良粳稻品种南34为亲本,将正反交杂合体在4个海拔产生的F2群体种植在2200m海拔点对其生物学性状进行遗传分析.结果表明,两亲本在低温下种植其生物学性状存在极为明显的差异,而正反交F1的差异则主要表现在穗长和结实率上;在不同海拔产生的正反交F2群体中生物学性状的变异系数、遗传率、遗传进度、偏度、蜂度等遗传参数的表现存在极为明显的差异.经次数分布的卡方检验表明,所有性状均显著或极显著偏离正态分布;其中,在所有F2群体中穗长和结实率均偏向小麻谷,然而有效穗数、1～2穗节长、穗颈长、总粒数和着粒密度均偏向南34;株高在F2群体中的偏向受细胞质背景和产生F2群体海拔的影响.此外,F2群体的形态多样性和遗传分化明显受到细胞质和海拔的影响.该研究结果对探讨环境温度对细胞质效应的影响具有重要的参考价值.

The genetic differences of biological characters were analyzed in F2 populations generated from reciprocal hybrids at four different altitudes planted at 2200 m elevation.The material parents were Xiaomagu（XMG）,Japonica rice landrace that had strong cold tolerance,and N34,an improved japonica variety that cytoplasm was donated by Indica rice.The results showed that the biological characters between parents had significant differences planted at low temperature,but the significant difference between reciprocal F1 ouly exists in panicle length and seed set.However,the variation coefficient,broad heritsbility,genetic advance,genetic skewness,and kurtosis of the biological characters in F2 populations had obvious difference.Thex2 test shooed that all observed biological characters were significantly distortel from the normal distribution （P ＜ 0.05 or P ＜ 0.01）.Among them,two characters of panicle length and seed set skewed toward XMG; however,five characters of effective panicles,panicle node length,neck length of spike,total grains per panicle and grain density skewed toward another parent N34 ; the deviation of plant height was influenced by F2-generated altitudes and cytoplasmic backgrounds.In addition,the morphological diversity and genetic differentiation were also affected by F2-generated altitudes and cytoplasmic backgrounds.The results could be reference for discussing the effects of environmental temperature on cytoplasmic effects.