Identification And Genetic Analysis Of A New Dwarf Mutant Gene In Maize

The practice of breeding has proved that every breakthrough of breeding can not get away from the discoveries and use of favorable genes. In terms of the breeding of rice, the dwarf breeding of the 1960s based on the discovery and use of dwarf gene sd, and the breakthrough of crossing breeding rice can not independent from the founding of pollen abortion plant of wild rice and the Three are forming a complete set from three branches of the 1970s. With the continuous discoveries of new dwarf materials, the identification of new dwarf genes and the study on the relationships between different dwarf genes and the values of use of different genes are becoming more and more urgent.This study was made on dwaf gene Dt of dwarf mutant derived from the offsprings of maize hybrids CL1077 based on the understanding that the dwarf gene is controlled by a pair of dominant gene in nuclue. To prove gene Dt as a new maize dwarf gene, we conduct the following work: identification of the sensitivity of gene Dt to gibberellic, comparison and allelic analysis of gene Dt with dominant dwarf gene D8 (Mpl1) and D9, and analysis of gene Dt based on ISSR Markers .And the study shows:1. If gene Dt is allele, it may only be an allelic gene of D8 or gene D9, and may not be and allelic gene of br of other recessive gene. The Dt dwarf mutant was sensitive to gibberellin while materials that contain D8 and D9 were insensitive to gibberellin. The Dt gene was a dominant dwarf gene and it was mapped on chromosome the long arm of 10 in maize. It was reported that there were only two dominant dwarf genes- Dwarf8 (Mpl1) and Dwarf9, which was located on chromosome1long arm and chromosome 5 short arm, respectively. Moreover, allelic analysis between Dt and D8 or D9 indicated that Dt was a non-allele gene of D8 or D9. The result showed that Dt gene was a new dominant dwarf gene in maize ulteriorly.2. Sifting 6 attracting things that can produce steady different areas out from 112 ISSR molecular markers.The target straps of UBC825﹑UBC836 and UBC878 ISSR probses of these 6 are stronger than others especially.Amplification production and dwarf gene are linked together, and their exchange rate are as follows:4.84%,8.06% and 9.67%.These results revealed the relationship between, the hereditary mechanism of gene Dt and other dwarf genes of maize provided a theory base for the use of the gene. The research also made a first step analysis on dwarf genes at the molecular level.