水稻浆片颖壳化突变体(gll)的鉴定和精细定位

【目的】鉴定和克隆水稻花器官突变体新基因,对了解水稻花器官发育的分子遗传机理和分子信号调控途径有着重要的作用。【方法】采用田间种植鉴定、突变体和野生型的花器官对比、杂交后代的表型分离统计及基于图位克隆法的基因定位等方法,对自然突变产生的突变体gll的表现型、遗传和基因精细图位开展研究。【结果】表型鉴定认为gll突变体小穗上的颖花变异主要表现为浆片颖壳化和外颖增加。通过杂交F1、F2及F3的表型分离个体χ2测验结果表明,该突变体表型分离符合1对隐性核基因的比例。配制突变体和日本晴的杂交种及其F2分离群体,在F2和F3群体中获得gll表型株作为基因定位群体。利用均匀分布于水稻12条染色体上的156对多态性分子标记,检测gll定位群体中的408株突变体表型个体,将GLL定位于水稻第1染色体上SSR标记RM1068和RM3482之间,遗传距离分别为4.6和2.3 cM。随后检测了4个新的SSR标记,进一步将GLL定位在108 kb的物理距离之内。【结论】水稻gll突变体的性状由1对隐性核基因控制,该基因位于第1染色体长臂的近下端SSR标记RM6097和RM6827之间108 kb范围内。

Identification and Fine Mapping of a Glume-Like Lodicule Mutant in Rice (Oryza sativa L.)

【Objective】 The identification and cloning of novel mutant genes of floral organ in rice would play an important role in understanding the molecular genetic mechanisms and molecular signal pathways regulating floral organ development. 【Method】Field identification, comparison between mutant and wild-type floral organs, statistics of segregation of different phenotypes as well as gene mapping based on map-based cloning were used to describe the characteristics of floral organ, to determinate the inheritance of gll mutant and high-resolution mapping of GLL gene. 【Result】 It was shown that a wide variety of spikelet developmental defects exhibited from outer to inner floral organs in gll mutant, and the main mutant phenotypes were glume-like lodicule and the extra glume. The Chi-square test of F2 and F3 individuals derived from four crosses indicated that the segregation ratio of phenotypes was consistent with the inheritance of single recessive nuclear gene. The plants with gll phenotype were obtained from F2 or F3 generations from Nipponbare×gll for mapping GLL gene. One hundred and fifty-six polymorphic molecular markers, which evenly distributed on 12 chromosomes in rice, were used to test 408 individules with mutant phenotype. According to statistical analysis, the GLL gene was located on rice chromosome 1 between RM1068 and RM3482 with a genetic distance of 4.6 and 2.3 cM to gll locus, respectively. Then, four SSR markers were developed within this region, gll locus was finally mapped on a region of 108 kb physical distance. 【Conclusion】 The gll mutant is controlled by a recessive nuclear gene, which is located on the long arm of chromosome1, between RM6097 and RM6827 with 108 kb physical distance.