Study On Maintainer Lines Of Aromatic Rice And Analysis Of Aroma Genetic

Rice is one of the most important food crops in the world. Yield and grain quality are always the two major goals for rice breeding. Traditional aromatic rice was popular in most customers because of aroma and texture. It is necessary to improve the yield and adaptation of traditional aromatic rice in order to increasing their area and meeting the needs of market. In the past years, development and application of commercial F1 hybrid rice have increased yields. But grain quality of hybrid rice was not satisfied. The problem is becoming more and more serious at present because of continuously increasing of living standard. So to enhance productivity of aromatic rice and to improve grain quality of hybrid rice by using aromatic germplasm were two approaches for quality and high-yield breeding in rice.In this paper, major agronomic traits and grain quality traits affecting rice yield and grain quality were investigated in seven aromatic rice maintainer lines bred in Sichuan and one variety introduced from America. It was aimed at estimating the numbers of gene controlling aroma, the allelism of aroma genes, location of aroma gene(s) on the chromosome, and molecular tagging of aroma gene. The results were summarized as follows:1. Correlation analysis and principal component analysisThe relationships were complicated among agronomic traits and grain quality traits. We discovered that the factors of Length / Width and head rice ratio affecting rice grain quality were most important. And the factors of panicles per plant and main panicle length affecting rice yield were most important.2. Cluster analysisCluster analysis resulted from principal component and systems analysis resulted form SSR showed that the genetic diversity was small and the genetic background was narrow among those aromatic varieties.3. Genetic analysis of aromaLack of leaf aroma in all F1 plants of aromatic / non-aromatic crosses indicated therecessive nature of aroma. The segregation ratios (3 : 1, 1 : 1) of non-aromatic to aroma plants in F2 and BC1F1 populations from non-aromatic / aromatic maintainers crosses revealed that each of the seven aromatic maintainers contains a single recessive gene for aroma. But aroma genes of all seven maintainers are not allelic. The segregation ratio (13 : 3) of non-aromatic to aromatic plants in F2 population from Luxiang 90 / Feigai B cross revealed that it contain one inhibitor gene and one aroma gene.4. Molecular tagging of aroma gene in D-xiang 2 B and Luxiang 90 The BC1F1 populations, derived from D-xiang 2 B/ Feigai B// D-xiang 2 B and Luxiang 907 Feigai B// Luxiang 90, were used to screen molecular markers linked with aroma gene, subsequently, one aroma gene of D-xiang 2 B was mapped near to RM210 and RM515 on chromosome 8, with distances of 17.3 cM and 5.7 cM respectively. And one aroma gene of Luxiang 90 was also mapped near to RM515 on chromosome 8, with distances of 4.3 cM.