一个水稻白化转绿突变体的遗传及光合生理特性分析

Analyses of Genetic and Photosynthetic Physiological Characteristics of a Green Revertible Albino Rice Mutant

从大田育种材料中发现一份水稻（Oryzn sativa）苗期白化转绿突变体，该突变体2～4叶从边缘部分向内白化，2、3叶白化严重，第4叶转绿，以后叶色均趋于正常，前面白化3叶也逐渐转绿，以后生长基本与野生型相同。遗传分析表明．该基因由1对隐性核基因控制。在人工控温条件下研究表明．突变体为温度敏感性．其白化临界温度为24℃。在大田种植条件下对苗期、分蘖盛期及孕穗期的叶片叶绿素含量和光合速率进行测定。结果表明．3叶期突变体叶绿素含量仅为野生型的36％；分蘖盛期和孕穗期叶绿素含量与野生型相当；转绿后（5叶期）至孕穗期两者在净光合速率、蒸腾系数、胞间CO2浓度、气孔导度等光合特性参数方面相差无几。该突变体仅在苗期表现且易于识别．转绿后对农艺性状及产量影响不大，为理想的标记性状。

A green revertible albino （gra） mutant was found from the rice breeding matierals. The mutant turned albino from edge to inter of leaf in 2-4 leaf stage. The 2nd and 3rd leaves were albino seriously. The 4th leaf turned green and the following leaves were normal green. At the same time the initial three leaves gradually convert to green, then the mutant plant is similar to the wild type. Genetic analysis showed that the trait was controlled by one nuclear recessive gene. The mutant was cultured under different tempretures, which revealed that the mutant was sensitive to low temperature and the albino leaves appearred below 24 ℃. In field condition the chlorophyll contents of mutant were 36% compared with the wild type at 3th leaf stage and then was similar to wild type from the 5th leaf stage to booting. The photosynthetic physiological traits of the mutant and the wild type including net photosynthetic rate （Pn）,transpiration rate （Tr）,stomatal conductance （Gs） and intercellular CO2 concentration （Ci）, had no difference from 5th leaf stage to booting. The mutant was albino at seedling stage. The phenotypic trait was easy to he identified. It had no harmful effect on final grain yield after turning green. It will be an ideal marker in rice breeding.