Genetic Analysis And Gene Mapping Of A Rice Dwarf Mutant With Yellow Leaf

Rice height characters are one of the most important agronomic traits of rice. Over higher plant would easily result in plant lodging and output reducing. The utilization of the semi-dwarf gene sd-1 had led the green revolution of rice breeding. Researching to the dwarfism makes for increasing the variety of using of dwarf fountain, avoiding oneness of the dwarfism breed genetics, and also creating condition for the break through of rice breeding production. Dwarf breeding had made a great breakthrough in the rice breeding, so it is very important to unearth new dwarfism, investigate their dwarf genes, and finally make use of these genes.In this study, a yellow and dwarf material Gao Huang Ai was crossed with different height materials, after their height and separation frequency were analyzed, that the configuration characters and the genetic rules of Gao Huang Ai were researched. And also the dy(t) gene ofHuang Ai was farther orientated by SSR markers. The main results of this paper are summarized as follows:1. The height of Gao Huang Ai was about 76cm, 26cm lower than the semi-dwarf wild type's height, but 38cm higher than the mutant Hangai' s height. The Gao Huang Ai' leaves behaved normal green color in the seeding stage, but leaves of the mutant started to appear yellow on the top of the last second after about a month growth, and along with growing, the last third leaf stated searing and dilapidating. Except the lengths of three upper internodes, other characters are lower than its wide type.2. The material Gao Huang Ai was sensitively to the hormone GA₃ and BR, GA₃ had the affection of increasing the height; BR had the affection of restraining the height, but more violence than restraining its semi-dwarf wild type's height.3. The mutant in the seeding stage were separately treated with gibberellins acid The chlorophyll content in the leaf Gao Huang Ai was lower than that of its semi-dwarf wild type, and also the ratio of its chlorophyll content and caro content was still lower than that of its semi-dwarf wild type. The ultra structure of the material Gao Huang Ai was detected that the number of grana and matrix degenerated along with the present of its yellow leaves, meanwhile there were many big vesicles in the chloroplast, and large numbers of faecula grains were abounded in the big vesicles. On the other hand, the roots energy of Gao Huang Ai was higher than that of Huang Ai and its semi-dwarf wild type.4. After crossed with different height materials, the genetic analysis indicated that the dwarf character of Gao Huang Ai was controlled by a pair of recessive gene, and this gene was not allelic to the locus sdl, sdn and sdg. Except that the gene was not only the hosts affect gene controlling height, but also the gene resulted in yellow leaves, it behaved one gene much effect.5. According to the result of genetic amylase, the F2 population of Huang Ai and 9311 was used for the map population. The gene was mapped on rice chromosome 9 by utilizing the method of SSR markers binding with populations analyzing. The gene was linked with the SSR makers RM7481, RM444, the genetic distances from the target gene to markers RM7481 and RM444 were 4.4cM and 2.5cM. Based on the represent, genetic analysis result and gene mapping result, the gene could confirmed to be a new gene, was temporarily named to be Sdy (t).