Physiological and biochemical analysis and identification of a short season cotton virescent mutant | 一个短季棉芽黄基因型的鉴定及生理生化分析

Chinese. 目的鉴定新的早熟棉花芽黄突变体，为揭示航天诱变机理和芽黄突变体的利用提供理论基础。方法以中棉所58芽黄突变体为材料与野生型、棉花中期库17份芽黄材料进行正、反交，通过遗传学分析、叶绿体的超微结构观察和抗氧化系统酶活性测定，比较中棉所58芽黄突变体Vsp与野生型的各性状差异。结果中棉所58芽黄突变体Vsp和野生型中棉所58正、反交F2叶色表现符合绿叶s黄叶为3s1的分离结果，说明该突变体的芽黄性状由隐性核基因控制，中棉所58芽黄突变体Vsp和其它17份芽黄材料正、反交，虽有材料杂交后代有极个别表现芽黄表型，但绝大部分（95%以上）都表现为正常绿色，说明控制中棉所58芽黄突变体Vsp芽黄性状的基因和其它17份已经鉴定的芽黄材料控制该性状的基因不等位。叶绿体的超微结构表明，芽黄突变体叶绿体发育存在一定的缺陷，发育比较滞后，基粒类囊体和基质类囊体垛叠数较少，排列比较混乱，但随着叶片的不断发育，之后逐渐达到野生型的发育水平。芽黄材料的株高、果枝数、大铃、小铃、产量和纤维品质显著低于对照，芽黄突变体的SOD和CAT活性低于对照，POD活性高于对照，说明其抗氧化能力远低于对照。结论利用航天诱变技术，经过多代连续自交，获得芽黄性状稳定遗传且不同于棉花中期库17份已有芽黄材料的芽黄突变体中棉所58Vsp，该芽黄性状受一对隐性核基因控制；该芽黄突体的抗氧化系统酶活性、色素含量、叶绿素合成前提物质及叶绿体的超微结构均受到一定的影响。

English. Objective The purpose of this project was to identify a new early cotton virescent mutant for explanation of the mechanism of the space mutagenesis and application of virescent mutant. Method Reciprocal crosses were made between the virescent mutant and wild type and 17 virescent materials came from the medium term warehouse of cotton germplasm resource in China. The characters were compared between the virescent mutant and wild type by genetic analysis, chloroplast ultrastructure, and antioxidation enzymes. Result Leaves color proportion of F2 progeny was 3:1 between green and yellow. The results of reciprocal crosses were same between the virescent mutant and wild type. Therefor, the virescent trait was controlled by a recessive genes. Leaves color of F1 progeny was green between the virescent mutant and 17 virescent materials except several yellow plants. These were proved that genes of the virescent trait was nonallelic with 17 virescent materials. The results of chloroplast ultrastructure showed that chloroplast development of the virescent mutant was deficiency and slowly, less grana and stroma and chaos. Chloroplast structure was gradually recovered to normal level as leaves development. Plant height, branch fruit numbers, bolls, little bolls, yield and fiber quality of the virescent mutant were significantly lower than wild type. SOD and CAT activities of the virescent mutant were lower than wild type, but tha activity of POD was higher. Conclusion The new stable genetic virescent mutant was identified which is controlled by a recessive allele and different with 17 virescent materials by space. Many characters of the virescent mutant, such as the activity of antioxidation enzymes, pigment content, the materials of chloroplast synthesis and chloroplast ultrastructure, were affected, by space mutagenesis.