水稻不同穗型品种幼穗分化相关基因表达分析

Analysis of gene expression related to young panicle differentiation of rice varieties with different panicle types

试验选择与水稻幼穗分化相关基因和不同穗型粳稻品种,通过盆栽试验比较分析不同穗型品种间穗部性状及幼穗分化相关基因转录表达量遗传差异和相互间关系,旨在为解析水稻穗部性状形成转录调控机理和开发超高产栽培技术等提供理论依据。结果表明,根据每穗总粒数可将6个供试品种划分为多粒型、较多粒型和少粒型品种,3种不同穗型品种间每穗总粒数遗传差异显著;随幼穗生长,供试不同穗型品种幼穗OsCKX5、OsCKX9、OsRR2、OsRR5、OsLOGL2、OsLOGL3基因mRNA表达量均持续升高,上升幅度较大;不同穗型品种间幼穗生长不同时期幼穗上述6个基因mRNA表达量遗传差异较大;在幼穗生长过程中,上述6个基因mRNA表达量多粒型品种高于较多粒型和少粒型品种,较多粒型品种又高于少粒型品种;每穗总粒数、每穗二次枝梗数和每穗二次枝梗粒数与幼穗上述6个基因mRNA表达量均呈显著或极显著正相关,通过mRNA表达量正向调控每穗颖花分化和形成,基因表达量上调有利于增加每穗颖花数。

In this pot experiment,different panicle types of rice varieties and related genes were used to compare and analyze the genetic differences between the panicle traits and the transcriptional expression levels of six genes related to panicle differentiation as well as the relationship with each other,to provide a theoretical basis for elucidating the transcriptional regulation mechanism of rice panicle trait formation and developing super-high-yield cultivation techniques.The results showed that six rice varieties were categorized as multiple-grain variety,more-grain variety and fewer-grain variety by the total number of grains per panicle,thus the significant genetic variation was detected in the total number of grains per panicle in the above three types of rice varieties.In the process of young panicle differentiation,the gene expression level of OsCKX5,OsCKX9,OsRR2,OsRR5,OsLOGL2 and OsLOGL3 varied and were up-regulated significantly,which was in close relation to the total number of grains per panicle,and was significantly or extremely significantly positive correlation with the number of the secondary branches per panicle,the grain number of secondary branches per panicle and the total number of grains per panicle.Therefore,the above genes positively regulated the differentiation and formation of spikelets per panicle through mRNA expression,whose expression level was positively related with the spikelets per panicle.