海拔和籼粳细胞质背景对水稻F2代群体杂种优势和自交衰退的影响

Influence of altitude and indica-japonica rice cytoplasmic background on heterosis and inbreeding depression of rice F2 generation populations

  • 摘要: 【目的】分析海拔引起的环境温度变化对籼粳稻细胞质背景下的F1代配子基因型的选择效应及其对后代分离群体优势和衰退的影响,为水稻育种及全球气温变化对水稻遗传变异的效应研究提供理论参考。【方法】以具有籼稻细胞质背景的改良粳稻品种南34与耐冷性极强的粳稻老品种小麻谷为亲本,将正反交F1代种植在3个海拔条件下产生6个F2代群体,对其11个生物学性状的杂种优势及自交衰退进行分析。【结果】株高、剑叶长、剑叶宽、有效穗数、主穗长、穗颈长、实粒数和结实率8个性状的自交衰退在6个F2代群体中均达显著(P<0.05,下同)或极显著(P<0.01,下同)水平,播始历期、1~2穗节长和着粒密度等3个性状的自交衰退在部分F2代群体中达显著或极显著水平。正反交组合F2代群体中播始历期、株高、剑叶宽、有效穗数、实粒数和结实率6个性状的杂种优势和自交衰退均随海拔的升高而减小,剑叶长、主穗长、1~2穗节长、穗颈长和着粒密度5个性状的杂种优势和自交衰退在正反交组合中具有明显的差异。F2代群体生物学性状的中亲优势率、超亲优势率和自交衰退率明显受到产生F2群体的海拔和细胞质背景的影响。【结论】海拔和细胞质背景对水稻F2代群体杂种优势及自交衰退产生的效应,分别是由于海拔导致的环境温度变化对杂种F1代的雄配子选择以及不同细胞质背景下由雄配子和雌配子共同选择造成。此外,海拔对F2代群体当代的孢子体同样具有非常明显的效应。

     

    Abstract: 【Objective】 To study influence of environmental temperature changes due to different altitudes on selection effect of F 1 generation gamete genotype under indica-japonica rice cytoplasmic background and advantage and depression of progeny separation population,in order to provide theoretical reference for rice breeding and study on effects of global temperature change on rice genetic variation.【Method】 N34,an improved japonica variety with indica-japonica cytoplasmic background,and XMG,an old typical japonica rice variety of strong cold tolerance,were taken as parents. Six F2 populations were generated from reciprocal hybrid of F1 generations at 3 different altitudes, and 11 biological traits of heterosis and inbreeding depression were analyzed.【Result】Inbreeding depression of 8 traits such as plant height, flag-leaf length, flag-leaf width, effective panicle number, main panicle length, panicle neck length, filled grain number and seed setting rate were significant(P<0.05,the same below)or extremely significant(P<0.01,the same below)in 6 F2 populations. Inbreeding depression of 3 traits such as duration from sowing to heading,1st-2nd panicle node length and grain density were significant or extremely significant in some F2 populations. In reciprocal hybrid combinations of F2 populations, heterosis rates and inbreeding depression of 6 traits in F2 population, such as duration from sowing to heading, plant height, flag-leaf width, effective panicle number, filled grain number and seed setting rate, decreased as altitude of F2 population generation increased. Variation trend of heterosis performance and inbreeding depression rate of other 5 traits including flag-leaf length, main panicle length, 1th-2nd panicle node length, panicle neck length and grain density with altitude were greatly different in reciprocal hybrid combinations. Among biological traits of the F2 population,mid-parent heterosis rate, super-parent heterosis rate and inbreeding depression were greatly affected by altitude and cytoplasmic background of F2 population.【Conclusion】Effects of altitude and cytoplasmic background on heterosis and inbreeding depression of F 2 population in rice are caused by hybrid F1 male gamete selection due to environmental temperature change at different altitudes, and co-selection of male and female gametes under different cytoplasmic backgrounds, respectively. In addition, altitude also greatly affects contemporary sporophytes of F2 population.

     

/

返回文章
返回