水稻阶段性返白突变体的鉴定和候选基因分析

从粳稻品种中花11 的后代中发现了一个叶色突变体sgra, 该突变体幼苗期叶色正常, 而6~8 叶期以后新生叶白化, 随后白化叶转绿. 突变体的遗传分析表明, 该突变体表型受1 对隐性核基因控制. 利用籼粳杂交F2群体对突变位点进行了基因定位, 将其定位于水稻第11 染色体的2 个标记ID343-11 和PSM415 之间, 遗传距离分别为0.9 和1.0 cM. 随后, 利用已公布的水稻序列和SSR标记, 在两标记间发展了9 对新的标记, 进一步将SGRA基因定位在IDM-2 和RM26739 之间, 物理距离约为17.6 kb. 对野生型和突变体候选区段基因组DNA 测序分析表明, 候选基因编码一个ABC 转运蛋白.

Identification and candidate gene analysis of stage green-revertible albino mutant in rice (Oryza sativa L.)

A rice leaf color mutant was obtained from a japonica variety, Zhonghua 11. The mutant and Zhonghua 11 had very few differences in seedling leaf color at the 1- to 5-leaf stage. The mutant had albino leaves at the 6- to 8-leaf stage and then reverted to the normal green color. Genetic analysis showed that the mutant was controlled by a single recessive gene, designated as sgra (stage green-revertible albino). A genetic linkage map was constructed using a large F2 mapping population derived from a cross between the mutant and an indica variety, Huajinxian 74. The SGRA gene was mapped between the markers ID343-11 and PSM415. Fine mapping, conducted with nine newly developed molecular markers based on the sequence diversity around the region harboring SGRA in Nipponbare and 93-11, delimited SGRA to a 17.6-kb region between markers IDM-2 and RM26739. Genomic sequencing of the region between these two markers in Zhonghua 11 and the sgra mutant revealed that the candidate SGRA gene encodes an ABC transporter.