水稻卷叶突变体rl28的特性与基因定位

叶片是光合作用的主要器官,适度卷曲有利于改善群体光照,提高光能利用率,因此,发掘和研究叶片发育相关基因是改良株型和植物生长发育研究的重要基础工作。本研究报道了一个新的水稻稳定遗传卷叶突变体rolled leaf 28(rl28),与野生型相比,rl28从拔节期起叶片开始沿中轴脉向内侧卷曲,叶片的卷曲度均极显著高于野生型,且叶夹角也不同程度小于野生型。扫描电镜及石蜡切片观察表明,rl28叶片单位面积气孔数、气孔导度显著高于野生型,蒸腾速率极显著高于野生型,rl28中脉增大及临近的2个泡状细胞数量减少。遗传分析表明该突变性状受1对隐性核基因控制,RL28基因被定位在第5染色体标记5-43和5-34之间,物理距离为90 kb。本研究将为RL28基因的图位克隆及功能研究奠定基础。

Characterization and Gene Mapping of Rolled Leaf Mutant 28 (rl28) in Rice (Oryza sativa L.)

Leaves play a very important role in plant development for their function of photosynthesis. Moderate rolling leaves can facilitate the improvement of plant’s population structure and enhance light-use efficiency, which is very important in ideotype breeding. Therefore, the rolled leaf genes which regulate morphology in rice are important for exploring plant type and improving basic research in molecular biology. This study reported a new gene rolled leaf 28 (rl28), which was derived from EMS-treated restorer line Jinhui10. The mutational trait inherited steadily after several generations’ self-crossing. Compared with the wild-type, the leaves of rl28 began to curl along ?the vasculan bundle in medial axis from booting stage, leaf rolling index was significantly higher than that of the wild-type, and leaf angles were less than those of wild-type. Scanning electron microscopy and morphological analysis showed stoma number per 10-5 m2 and stomatal conductance were significantly higher than those of the wild-type, transpiration rate was significantly higher than that of wild-type. Compared with the wild-type, midrib of rl28 was much larger, and the number of the two adjacent vesicular cells decreased. Genetic analysis showed that the mutational trait was controlled by a single recessive nuclear gene. RL28 was finally mapped on chromosome 5 between SSR markers 5-43 and 5-34 with an interval of 90 kb. These results provide a foundation for cloning and function analysis of RL28.