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Analysis on Genetic Diversity Classification and Heterosis in Rice of Indica-Japonica Cross

Author: YangWangXing
Tutor: QiJianMin；XuXuMing
School: Fujian Agriculture and Forestry University
Course: Biological Engineering
Keywords: Rice Subspecific Indica and japonica rice germplasm Strain Diversity Indica and japonica Category Heterosis
CLC: S511.2
Type: Master's thesis
Year: 2010
Downloads: 97
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Abstract

Rice indica and japonica subspecies of genetic distance larger hybrids have a larger variation and significant Hpb take full advantage of heterosis between different ecotypes or subspecies subspecies has become today's breeding One of the main ways. Indica and japonica subspecies of rice diversity and heterosis analysis and research on the rational use of subspecies heterosis has important theoretical and practical significance. 39 derived lines of indica and japonica and 17 indica and japonica pro this material, using phenotypic traits and SSR molecular marker two cluster analysis methods, test material groups divided, comparative studies and genetic diversity analysis to explore genetic diversity of rice indica and japonica subspecies indica and japonica classification attributes. At the same time, select one of the 12 representative indica and japonica rice material with 8 widely used in the production of two-line, three-line sterile line with the group, using SSR markers between parental genetic diversity and phylogenetic relationship, calculate the combinations The genetic distance between the parental and then analyzed the correlation between genetic distance and its heterosis performance. Selection of breeding parents in order to reduce the blindness of the distribution group, to improve the effectiveness of the indica and japonica rice heterosis utilization and to improve the efficiency of hybrid rice breeding to provide a reference. The main findings are as follows: 1, phenotypic cluster analysis results show that the clustering does not accurately reflect the genetic relationship between all materials, but can accurately reveal differences in morphology between the parent material and more accurate dominant groups together an important reference value for the study of heterosis with groups of different materials. Found in the test, the phenotype clustering groups of the dominant group, Emphatic and extensive distribution group and its subsets Indica and partial the indica parent material, they are generally better with selection sterile line with group able to produce the combination of advantages; its 2 subsets indica and japonica intermediate material has both general indica characteristics, there are some japonica characteristics, good specific combining ability selection tillering ability, strains The type is shorter the better affinity Indica, Japonica CMS Line with the group, the more prone to strong heterosis. SSR molecular marker clustering analysis results show that the clustering classification results with phenotypic clustering results more consistent access to the test materials pedigree, comparative molecular clustering results, it can be seen to can be reflected from the molecular level all varieties the differences between, and a more accurate understanding of the genetic relationship of the tested materials, and SSR molecular clustering can be used for the unknown materials phylogenetic relationship as well as the division of the dominant groups. 3, SSR molecular marker genetic diversity analysis showed that the Nei genetic diversity index, Shannon diversity index and polymorphic information content (PIC), the maximum indica and japonica rice strains were greater than the parental Nei gene diversity index the maximum is 0.819, the parents to 0.796; indica and japonica rice strains Shannon diversity index maximum 185.6 parents 1.677; indica and japonica rice strains polymorphic information content (PIC) maximum of 0.796 parent 0.766; shows that, after years of generations replacement of select strains of indica and japonica rice is richer than the parent allelic variation. 4, this study proposes two DNA level indica and japonica classification criteria for the classification: ① The 85% classification criteria: japonica (85% -100%), japonica (50% -85%), partial Indica (15% -50%) , Indica (0% -15%). ② 70% classification criteria: japonica (70% -100%), japonica (30% -70%), partial Indica (15% -30%), Indica (0% -15%). Can be seen from the experimental analysis, the correlation of the two molecular markers classification method and program classification showed significant classification criteria of 85% and he was admitted to the morphological index classification extremely significantly related (r = 0.96 **), 70% of classification criteria program morphological index classification significantly correlated (r = 0.89 *), two molecular markers classification method can effectively divided the varieties of indica and japonica classification, with respect to the latter, the former is more suitable. Analyzed from the perspective of parents and the indica and japonica rice strains, 85% of the classification criteria in the classification of the parents and the indica and japonica rice strains were less than 70% of the classification criteria (compared to the classification and morphology index), parental inconsistency were 5.88%, 11.76% indica and japonica rice strains inconsistencies were 20.51%, 25.64%. It can be seen that the morphological classification of indica and japonica rice strains with DNA classification inconsistency was significantly higher than the parental; indica and japonica rice strain the morphological index integral japonica gene frequency degree of correlation (r = 0.65 **) compared with the parent The morphological index total score japonica gene frequency degree of correlation (r = 0.89 **), has once again proven to judge the complexity of the indica and japonica rice strains classified description of indica and japonica rice strains of indica and japonica status is more difficult to determine, most of them for the middle type, range between indica and japonica rice, and its Chief has the characteristics of indica and japonica rice. Therefore, I think, should be based on the morphology index classification-based classification of indica and japonica rice strains, molecular markers classified supplemented; indica or japonica classification, classification should be based on molecular markers mainly supplemented by morphological index of classification. Indica and japonica rice strains with group heterosis analysis showed the the Minghui series indica and japonica rice lines have the following characteristics: plant height significantly positive heterosis minor variation, only a combination of 96 portfolio performance is negative to advantage; ear length performance forward Hpb, minor variation; Grains forward pro advantage is not large, the magnitude of variation; grains per panicle and seed setting rate showed strong positive advantage of the low seed subspecific hybrids problem has been largely overcome, but its amplitude is relatively large, obviously there are still some differences in performance recovery Series indica and japonica rice strains progenies; effective panicles showed negative advantage to the pro, indica and japonica rice strain F1 Hybrids in tillering relatively weak and needs to be improved. As can be seen, although the the Minghui series indica and japonica rice strains hybrids F, effective panicles, grains per panicle and grain weight relative performance unbalanced individual yield traits elements positive heterosis is not obvious, but because with group of parents complementary traits between the parents, so that the selected combination also showed strong yield advantage. 6, molecular genetic distance and heterosis analysis showed that 96 combinations within the range of 0.2547-0.5660 genetic distance and genetic distance of F1 seed setting rate, grain weight heterosis little effect is negligible, the effective panicles of heterosis have a certain influence, did not reach a significant level the little correlation coefficient (r = 011, r = 0.14), but in the height, ear length, per panicle, grains per panicle, grain yield per plant. plant height in pro advantage the Hpb genetic distance showed very significantly related (r = 0.44 **, r = 0.45 **), ear length pro advantage the Hpb genetic distance was a significant positive correlation (r = 0.39 **, r = 0.29 **), per panicle pro advantage the Hpb genetic distance was a significant positive correlation (r = 0.30 **, r = 0.32 **), each panicle grain number in the parent heterosis and genetic distance was significant with related (r = 0.23 *), Hpb with genetic extremely significant with positive correlation (r = 0.37 **), yield per plant pro advantage with genetic distance was a significant correlation (r = 0.23 *), Hpb genetic highly significant positive correlation (r = 0.34 **). This was evidence in range of 0.2547-0.5660 genetic, genetic distance reflects the size of the yield per plant, and Rebellion effective panicles seed from low temperatures or harsh conditions affect the next, you can take advantage of the parental genetic SSR markers distance heterosis prediction.

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