玉米白化突变体As-81647的鉴定及基因定位

白化突变体As-81647是在自交系81647的自交后代中发现的自然突变体。光合色素含量测定表明，白化突变体叶绿素a、叶绿素b、叶绿素总量分别为正常植株的0．6％、5．8％和1．6％，推测光合色素含量的减少导致突变体光合作用强度减弱，无法利用光能进行营养生长，进而造成突变体产生白化表型，三叶期左右萎蔫死亡。组织细胞染色实验证实H2O2的积累可能是造成突变体细胞死亡的直接原因之一。本研究构建了As-81647杂合突变体与蒙自2的杂交F2分离群体，遗传分析表明该白化性状由一对隐性核基因控制，暂时命名为As-81647（Albino seeding一81647）。利用已公布的SSR分子标记和本实验室开发的分子标记，将该基因定位在玉米第3染色体umc1052和ume1641之间，遗传距离分别为0．7cM和2．8cM且与分子标记as47共分离。

Identification and Molecular Mapping of an Albino Mutant Gene As -81647 in Maize （Zea mays L. ）

The albino mutant As -81647 was found from the offspring of maize inbred line 81647. Its chla, chlb and total chlorophyll contents were only 0.6%, 5.8% and 1.6% of those of normal plants, respectively. The deficient of the photosynthetic pigment led to the weakened photosynthesis, so the mutant could not utilize light energy, and then became albinism and died gradually before the three - leaf stage. The histochemical and cell staining study showed that the cell death of albino mutant was caused directly by excessive accumulation of H202. The F2 population was built between Mengzi 2 and hybrid mutant 81647 for genetic analysis, and the results indicated that this albino character was controlled by a pair of recessive genes, which was named as As -81647 （Albino seeding -81647）. The gene was mapped on the long arm of chromosome 3 （Bin3.09） with SSR markers; the distance between As -81647 and markers umc1052, asd7, umc1641 was 0.7 cM , 0 cM and 2.8 cM , respectively.