The Breeding And Identifying Methods Of Maize Haploid Induce By Stock6

Haploid breeding is a method of doubling the spontaneous or artifical haploid with colchicum, and selecting the super doubled lines. It could make the process of maize breeding faster, and the time of choosing a bred line shorter. Up to now, this kind of technique using Stock6 is one of the most efficient, common, and the fastest methods of selecting maize inbred lines. Genetic variability which is fundamental to succeed in crop breeding may be greatly increased through induced mutation. In this study, the Stock6 was used to research the different frequency of high haploid progeny, to compare the various methods of haploid identification, to investigate the natural fertility of haploid inflorescence, and to discuss the effective colchicum concentration of haploid doubling. The main results were as followed:1 Selection by selfing-cross was effective for Stock6. The percentage of ear lines, which were unable to induce haploid by selfing-cross, increased with the generation developing, i.e., the first generation had an average 30%, and this ratio became 88% through 5 selling selecting cycles, each cycle gained about 12% of enhancement. At the same time, the kernel Navajo marker was selected successfully. It was very clear in the sunshine, and easy to identify and separate the haploid seeds induced by Stock6 at the fifth generation. For the hybrid ears, more and more hybrid diploids / putative haploids were identified, and the proportion of actual haploid induced by stock6 was increased for 28.74%~49.64%. There was not significant selecting effect on the percentages of haploid from different maternal materials induced by Stock6, at shedding stage the percentages were between 1.19% and 1.93%.2 The methods of identifying maize haploid were studied preliminarily using the materials induced by Stock6. All methods via genes, such as kernel Navajo marker, plant height, the number of total leavies in growth stage, could be utilized for maize haploid identification. Among these characters, the kernel Navajo marker was able to eliminate about 98% hybrid diploids, which led to a laboursaving in haploid breeding. Distinctly, it was the most important method for identifying haploid. Based on the Navajo maker identification, plant height and the total leaf number in growth were the evidence to farther...