Genetic Analysis And Gene Mapping On A Novel Yellowing Mutant In Rice

Chlorophyll is the important pigment involved in photosynthesis in plant chloroplasts. Biosynthesis of chlorophyll is a very complicated process. Chlorophyll metabolism is influenced when certain location of plant genome occur aberrance, which lead to change of leaf color. Chlorophyll-deficit mutants of rice not only play an important role in researching photosynthesis of higher plants, biosynthesis of chlorophyll, genetic differentiation and development of chloroplast, but also serve as a marker character in utilization of rice heterosis. Therefore, the exploitation, research and utilization of chlorophyll-deficit mutant gene of rice have been highlighted.In this paper, a yellowing mutant, designated as" 824ys", was identified from rice line 824B. The morphological characters, agricultural traits, physiological characteristics and chloroplast ultrastructure of this yellowing mutant were studied. Genetic action of the yellowing character was analyzed by using the F₁ and F₂2 progenies from 824ys crossed with normal green original parent 824B and other line II-32B and 495R. Furthermore, this mutant gene was mapped preliminarily with microsatellite marker. The results are as follows:1 . The phenotype character of yellowing mutant 824ys is that leaf color is yellow-green. Furthermore, plant becomes short, the number of tiller reduces and growth stage prolongs. The whole plant of this mutant embodies yellowing character from the start of seedling. This mutant can't grow into strong seedling because it is in a disadvantageous place in competing sunlight under mixed sowing with normal green plants, which result in competitive death phenomenon in population.2. The photosynthetic pigment content of 824ys decreased significantly at three different growth stages, i.e.seedling, tillering and heading stage, compared with that of 824B. The chlorophyll content decreased by 58.10-66.66%. The carotenoid content...