水稻亲本籼粳分化程度与杂种优势的相关性

Correlation between the indica-japonica differentiation of rice parents and heterosis

[目的]分析水稻亲本籼粳分化程度与杂种优势的相关性,为研究双亲籼粳分化最佳配比及组配籼粳交强优势组合提供理论参考。[方法]采用ILP分子标记和程氏形态指数法对51份水稻亲本材料进行籼粳分化程度检测,基于23个ILP分子标记进行系统聚类分析,分析两种方法的相关性。按籼/籼、偏籼/偏籼、籼/偏籼、籼/偏粳、偏籼/偏粳和偏粳/偏粳6种类型配制150个杂交组合,综合分析亲本籼粳分化程度与杂种优势的相关性。[结果]采用程氏形态指数法从51份水稻亲本材料共检测出籼型20份、偏籼型19份、偏粳型6份和粳型6份;利用23对扩增结果稳定、条带清晰且只有两种等位基因的ILP引物从51份供试亲本材料中共检测出籼型14份、偏籼型20份、偏粳型11份和粳型6份,不存在100%纯籼或纯粳类型。ILP分子标记法与程氏形态指数法的籼粳分类结果均与系统聚类分析结果具有较高的吻合度,但仍在差异。51份供试亲本的粳稻成分指数与穗轴第1~2节长和抽穗时稃色呈显著正相关(P<0.05),与谷粒长宽比、酚反应和程氏指数总分呈极显著正相关(P<0.01),其中与程氏指数总分的相关系数最高,为0.81。随着组配双亲粳稻成分的增加,6种组配类型杂交组合的生育期、株高和每穗总粒数总体呈增加趋势,但单株有效穗数、结实率和千粒重总体呈下降趋势,单株重则呈先增加再下降的变化趋势。[结论]利用ILP分子标记可有效区分亲本的籼粳属性,是一种有效的水稻籼粳分类工具。采用籼/偏籼方式配组较易筛选到强优组合;虽然采用籼/偏粳方式配组获得高产组合的概率较低,但有机会获得极高产组合,在育种中亦可大胆尝试。

【Objective】The correlation between indica-japonica differentiation and heterosis was studied to provide theoretical reference for the optimum ratio of indica-japonica differentiation in parents of indica-japonica rice and intersubspecific hybrid rice combinations.【Method】ILP molecular marker and Cheng’s morphology index were used to detect indica-japonica differentiation level of 51 rice parents. And the correlation between the two methods was clustered by 23 ILP molecular markers. A total of 150 hybrid combinations were set based on indica/indica,partial indica/partial indica, indica/partial indica,indica/partial japonica,partial indica/partial japonica and partial japonica/partial japonica,and correlation between indica-japonica differentiation and heterosis was analyzed.【Result】There were 20 indica types,19 partial indica types,6 partial japonica types and 6 japonica types were detected from the 51 tested parents based on Cheng’s morphology index. Twenty-three pairs of ILP primers which had stable amplification products,clear bands and two alleles were used to detect 14 indica types,20 partial indica types,11 partial japonica types and 6 japonica types out of 51 tested parents. There was no 100% pure indica or japonica types. The indica-japonica differentiation results by ILP molecular marker and Cheng’s morphology index were highly consistent with clustering analysis but still different. Indica-japonica component index of 51 test parents was significantly positively correlated with length of the first and second rachis internode and glume color at heading stage(P<0.05),and was extremely positively correlated with length-width ratio of grain,phenol reaction and Cheng’s index total score(P<0.01). The correlation with Cheng’s index total score was the highest(0.81).With the increase of parental japonica rice composition,the six types combinations all showed an overall in creasing trend in growth period,plant height and total grain per panicle. But effective panicles per plant,seed-setting rate and 1000-grain weight decreased. The variation trend of single plant weight was firstly increased and then decreased.【Conclusion 】ILP molecular marker can be used to accurately detect the proportion of indica/japonica content in rice parent. It is an easy tool to classify indica and japonica rice. Fine combinations can be easily obtained through indica / partial indica combination. It is possible to obtain extremely high-yield combinations through indica/partial japonica,although the probability of obtaining high-yield combinations is low. It is worth trying in breeding.