水稻籼爪交重组自交系穗部性状变异分析

Analysis on the panicle traits variation of recombinant inbred line derived from the hybridization of Indica and Javanica

为研究四川水稻高产理想株系穗部性状的遗传特性,并筛选出高产且综合农艺性状好的新材料,利用籼稻CG133R与爪哇稻22号构建的重组自交系(RIL)群体,对其单株有效穗、一次枝梗数、穗长、每穗着粒数和千粒重等9个性状的遗传变异进行考查和相关性分析;对其单株产量与各农艺性状进行逐步回归分析与通径分析;对单株产量位列前8名的优系分析其穗部性状表现,并根据单株产量高低分成2组深入进行性状间的相关分析。结果表明,RIL群体穗部性状上发生了极广泛的变异。逐步回归分析和通径分析发现,水稻单株产量的主要贡献因素为有效穗>实粒数>千粒重。经过对其优系分析,初步确立四川稻区高产理想株系穗部性状的指标为有效穗数7~9个、一次枝梗数18~20个、穗长27.0~30.0cm、着粒数>320粒、实粒数>290粒、着粒密度>120粒/10cm、结实率81%~92%、千粒重20.0~27.0g。进一步对RIL群体中单株产量位列前4名的株系分析发现,其有效穗数和着粒数呈显著正相关(P<0.001)。表明打破了有效穗数和着粒数间的不利连锁关系,出现了优良变异。这些优系可作为新种质进行深入分析和利用。

In order to study the genetic characteristics of panicle traits for rice high yield ideal lines in Sichuan,and to select excellent new materials with good comprehensive agronomic characters and high grain yield, a recombinant inbred line （RIL） was constructed,which derived from two parents hybridization of Indica CG133R and Javanica rice 22. Genetic variation of 9 panicle traits, such as effective panicle number per plant, primary branch number, panicle length, grains per panicle, 1 000-grain weight etc were studied and their correlation were analyzed. Relationship of grain yield per plant and other agronomic traits were analyzed by stepwise regression and path analysis. Panicle traits of excellent lines that had high grain yield per plant ranked top eight were studied. They were divided into 2 groups according to grain yield per plant and there were further correlation analysis among the panicle traits. Results showed panicle traits of RIL population took place extremely extensive variation. Main contribution factors of grain yield per plant were effective spike number ~ filled grain number ~ 1 000-grain weight by stepwise regression and path analysis. Based on analysis of excellent lines,main indicators of panicle traits for ideal line with high grain yield in Sichuan were initially established： effective spike number 7 - 9, primary branch number 18 - 20, panicle length 27 - 30 cm, grains per panicle 〉320,filled grains per panicle 〉290, grain density 〉 120/10 cm, seed setting rate 81% - 92% and 1 000- grain weight 20 - 27 g. The excellent lines with high grain yield ranked top four in RIL population were further analyzed and found that there was significant positive correlation （ P^O, 001 ） between effective spike number and grains per panicle. Their unfavorable linkage was broken and appeared good variation types. The excellent lines should be further used and analyzed as new gerrnplasm.