Mutantion Induction And Genetic Pattern Analysis Of Sesame(Sesamum Indicum L.)Yellow Leaf Mutants

Chlorophyll deficiency is resulted from the specific gene mutation on the normal synthesis pathway of chlorophyll, as the chlorophyll content increased or decreased accordingly. The yellow leaf mutant, which is common in higher plants, contain a lower chlorophyll content than the normal plants. Leaf color mutants are worthy to be used in the studies of chloroplast structure, controlling, cloning and understanding the interaction of nucleo-cytoplasmic gene, and could be applied in crop breeding. Therefore, new leaf color mutants had been continuously explored and utilized in the past few years.The materials used in our research were the yellow leaf mutants, which were precious germplasm materials, selected from Yuzhi11after EMS inducing. In our study, morphological characteristics, major agronomic character and genetic regularity were analyzed and the main results are shown as follows. This experiment will provide special materials for the studies on photosynthesis mechanism and biosynthetic pathway of chlorophyll in sesame.1. the results of phenotype and quality identification of the1313mutants induced by EMS (ethylmethane sulfonate) with Yuzhi11seeds during2009-2012showed7different types of mutants, such as in the aspect of plant type, stem type, leaf type, floral organ, capsule, seed, male sterility, quality and so on.2. three types of mutant were found in their seedling period, including cotyledons with green color, yellow color and yellow-green color. Among them, the seedlings materials with green cotyledons were developed normally. However, the yellow color mutant seedlings were premature death with the depletion of cotyledon energy up. The third mutant types, who with yellow-green color, their leaf color was lighter than cotyledons’. Furthermore, their stem and capsule also showed somewhat yellow-green color and its mature period is about7d later compared with others. though the mutants could be fruitive, the fructification ratio and seed weight had somewhat decrease.3. Continuous selfing, hybridization of many generations and the reciprocal crossing with Yuzhi11were carried out, the selfing results showed that the F2mutant population separated into three types:bright yellow, yellow-green intermediate and green seedlings, and with the rate of1:2:1; the hybridization results with Yuzhi11showed only two color types with a1:1rate of yellow-green intermediate and green seedlings. The above results indicated that the leaf mutants of sesame were controlled by a paired of incomplete dominant gene. The bright yellow seedings were homozygous death, though yellow-green intermediate type with heterozygote could develop normally.