水稻颖花持续开放突变体sostenuto floret opening(sfo1)的鉴定与基因定位

摘要

水稻颖花开放是其生殖发育一个关键生理过程,对受精和随后种子发育具有重要影响.本文报道了一个与水稻颖花开放相关的突变体,来源于籼稻保持系西农1B的EMS(ethyl methane sulfonate)诱变群体.该突变体表现为开颖后浆片失水萎缩过程缓慢,内外稃持续开裂不闭合,暂命名为水稻颖花持续开放sostenuto floret opening 1(sfo1)突变体.遗传分析表明sfo1性状受1对隐性单基因控制,利用群体分离分析法(bulked segregation analysis,BSA)将SFO1基因定位在第5染色体SSR标记RM1054和IN/DEL标记ZTQ51之间,物理距离113 kb,含注释基因15个.本研究结果为SFO1基因的图位克隆和功能研究奠定了基础.%Rice floret opening is one of the most critical physiological processes in its reproductive development, which has a significant influence on the fertilization and subsequent seed development. Rice floret opening and closing are promoted respec-tively by the lodicules' expansion and shrink. In recent years, many studies focused on the molecular mechanism of rice lodicule development. However, few studies focused on the molecular regulation mechanism in physiological process of lodicule opening and closing. In this paper, we reported a floret opening mutant, sostenuto floret opening 1 (sfo1), derived from EMS (ethyl meth-ane sulfonate) mutation groups of Xinong 1B. During the floret opening stage, the florets of sfo1 and wild type were observed directly by both the stereoscope and the scanning electron microscopy at about 1 h before opening, and 10 min, 1.5 h and 48 h after opening respecting. Compared with that in the wild type, the sfo1 floret showed a delay of lodicules dehydration after floret opening, resulting in its failing to close the lemma and palea. Significant differences were not found at 1 h before opening, show-ing closed hulls, flat lodicules and well-stacked lodicules surface cells. At 10 min after opening, there were also no obvious dif-ferences between wild type and mutants, showing opening hulls, inflated lodicules, and smooth and well-stacked surface cells. At 1.5 h after opening, sfo1 hulls were not closed so big as those in the wild type. And sfo1 lodicules still inflated, but not dehydrated and atrophied as those in the wild type. At 48 h after opening, sfo1 hulls were not closed yet, its lodicules began to dehydrate and atrophy, but were still very full compared with those in the wild type. The F1 and F2 of a cross with sterile lines 56S as female parent and the sfo1 as male parent were used in genetic analysis and gene mapping, indicating that the sfo1 trait was controlled by a nuclear recessive gene. Using bulked segregation analysis (BSA) method, the SFO1 was located between the SSR marker RM1054 and Insert/Delete marker ZTQ51 on the chromosome 5, with a physical distance of 113 kb and including 15 candidate genes in this region. LOC_Os05g50890 and LOC_Os05g50900 were preliminary selected as candidate genes for SFO1. These results laid a foundation for the SFO1 gene cloning and functional research.