Genetic Analysis About Mutants Of Maize Obtained By Space Mutagenesis

Maize Research Institute of Sichuan Agricultural University (MRI, SAU) sent three excellent maize seeds which came from inbred lines 08-641,18-599 and RP125 for China's seed-breeding satellite, Shijian-8, in 2006. They were planted in Duoying Farm in Maize Research Institute of Sichuan Agricultural University at Ya'an of Sichuan Province in spring of 2007. The observed and contrasted plant which returned satellite seeds and seeds in ground, inbred with each generation and harvested the inbred seeds, the generation was wrote SP1, SP2, SP3 and so on. In order to find out the function of space environment in maize, genomic DNA was isolated from a bulk sample individual plants by space mutagenesis to analysis genetic diversity using simple sequence repeats method; the grain color variation mutant and sweet grain mutant was found in SP2 of three excellent maize inbred lines by space mutagenesis in 2008, the primary research indicated that the grain color and sweet grain traits was governed by a single homozygous recessive gene; three male sterile mutant was collected among three excellent maize materials, in order to determine the cytological mechanism of male sterile material induce by space flight, the male sterile material were used as experiment objects, the researches include several aspects:the sterility performance in field, the effect of restoration and the PCR identification. The main results concluded as follows:1. Genomic DNA was isolated from a bulk sample individual, plants by space mutagenesis, using 54 SSR loci distributed on ten chromosomes of maize, a total of seven primers with polymorphism were detected in the bulked DNA sample from inbred lines 18-599 by space mutagenesis, and five primers with polymorphism were detected in inbred lines RP125, indicated that DNA sequence structure changes by space mutagenesis.2. Respectively survey the seed germination rate of three maize inbred lines, the seeds by space mutagenesis treatment were lower than that of the control group of seed germination rate, space mutation processing of maize seed cause certain physical damage and reduce the seed germination rate, with the offspring of physical damage also generation continuity. In addition, different germination rate of inbred lines itself exists certain, space environment of physical damage degree is not the same.3. Through the space mutation processing, the nine grains with color vibration were collected, grain color variation is characterized with two kinds of different grain, the yellow color with white and purple, planting to observe its offspring. After x2 test, preliminary inferred by a variation of grain and yellow, purple and yellow alleles control characterized with the genetic variation rule generation is relatively complex, may be more interaction of genetic control. Analysis by simple sequence repeats diversity through the offspring of grain color variation of sample, we found that the genetic differences in different variation.4. Fourteen sweet maize grains was found when harvested seed of SP2, sweet maize endosperm mutations are two types including sweet maize and super-sweet maize, two kinds of the endosperm mutations clusters by sweet maize kernels and nor-sweet maize kernels, planting to and observe its offspring. After x2 test, sweet maize endosperm mutations that by a pair alleles gene control, sweet maize kernels performance is recessive, and nor-sweet maize grain is dominant. Based on sweet maize endosperm mutation materials by genetic diversity with simple sequence repeats, we found that the genetic differences between the sweet maize endosperm mutant lines.5. The three male sterile mutants was found in offspring of maize inbred lines 08-641, 18-599 and RP125 by space mutagenesis, male sterile materials respectively c8396, c8782 and c8613. According to the inbred of fertile plants and test-crossing of sterile plants test results that the three sterile material belong to the variation of cytoplasmic male sterility genetic types, and then to restore special effect and PCR cytoplasmic classification and identification, deduce three male sterility variation of C cytoplasmic male sterility genetic types. But there are some differences between three male sterile material, performance the different maintainer line. Amount of male sterility plant were be appeared in SP3 from inbred lines 08-641,18-599 and RP125 by mutantion processing, planting for and identification of genetic characteristics are analyzed.