哈密瓜叶色黄绿突变体Cmygl-1的高光合生理特性分析

叶色突变体是研究植物光合系统的结构和功能、叶绿素生物合成及其调控机制的理想材料.为了探究哈密瓜叶色黄绿突变体Cmygl-1的光合生理特性,以突变体、野生型近等基因系及F2遗传群体为试材,对叶色表型、农艺性状指标分别进行调查统计,并采用分光光度计法和试剂盒法分别测定叶绿素含量和酶活性,利用LI-6400光合仪和透射电镜分...

Photosynthetic and Physiological Characteristics Analysis of a New Yellow Green Leaf Mutant in Hami melon(Cmygl-1)

Leaf colo r mutants are ideal materials for the study of the structure and function of photosynthetic system,chlorophyll biosynthesis and its regulation mechanism.In order to investigate the photosynthetic characteristics of cmygl-1,the yellow-green leaf mutants of Hami melon,the wild-type near isogenic lines and F2 genetic group were used as the test materials.The genetic rule of mutant character was analyzed by F2 genetic segregation population,and the agronomic traits were investigated and analyzed.The chlorophyll content and enzyme activity were measured by spectrophotometer and kit respectively.And the photosynthetic characteristics and chloroplast structure were measured by li-6400 photosynthetic apparatus and transmission electron microscope respectively.The results show that the yellow green leaf character of the mutants could be inherited stably and was controlled by a pair of recessive allele;The content of photosynthetic pigment in the mutant leaves was significantly reduced,and the chloroplast membrane was fuzzy,the number of thylakoid lamellae was reduced,and the arrangement was loose;The net photosynthetic rate(Pn),gas pore conductance(Gs)of the mutant were significantly increased,the intercellular CO2 concentration(Ci)and transpiration rate(Tr)were not significant differences compared to the wild type,indicating that the high net photosynthetic rate of the mutant was non stomatal factor;In the low CO2 concentration environment,the net photosynthetic rate was significantly higher than that of the wild type,indicating that the mutant had strong CO2 fixation ability;The content of MDA and H2 O2 in the mutants increased significantly,indicating that the mutant suffered from membrane lipid peroxidation damage;The activity of POD and APX,GSH/GSSG were significantly higher than that of wild type,indicating that the mutant could activate its antioxidant system and scavenge excessive active oxygen substances in vivo;The activities of key photosynthetic carbon assimilation enzymes,such as PPDK,PEPC,1,5-diphosphate carboxylase/Rubisco were significantly higher than that of wild type,which might be the reason for the increase of net photosynthetic rate in mutants.It lays a foundation for the study of molecular regulation mechanism of high photosynthesis efficiency of mutants.