Comparative Study On Agronomic Traits And Genetic Analysis Of T-DNA Inserted Mutants

Rice is the staple food for more than one third of the world population. Because of its small genome size, relatively well developed genetic maps and easily to be transferred, rice is a model plant for functional genomics research. With the completion of sequencing of the rice genome, the post-genome era is coming. Namely, post-genome is functional genome and proteome. In order to research the functional genome of rice, researchers created a mass of rice mutants by various methods, and especially created many T-DNA inserted mutants, which contained the specific T-DNA as a tag of isolating the specific gene.In this study, we screened, identified and competed of the library of rice T-DNA inserted mutants, for ZH11 as receptor. The main results are following:1 The traits of T-DNA mutants, which mutated from ZH11,are investigated and screened. 1071 stable lines of phenotype variant are obtained.The traits, which mutated, include plant height, heading date,leaf colour, flower development and so on.173 out of 450 lines show T-DNA insertion by PCR testing with the specific primers of Bar gene.2 According to the data of field investigation, mutants were classified into two types, they were mutants which mutated on only one trait and mutants which showed comprehensive mutation. Traits that have been investigated of O700,O683,O719 and O720 behaved the same in two seasons, but the plant height and panicle length of 0684 and 0723 showed significant difference in two seasons.3 The mutant P1413 have less roots, most of which are brown, when compared with ZH11. The results of electrophoretic analysis of genomic DNA and electron microscopic observation of leaf cell also offered the evidence for the premature senescence phenotype of P1413. Data of traits investigation indicated that the plant height, 1000-grain weight et al. of P1413 have significant difference compared to ZH11.4 A rice (Oryza sativa L.) plant with white midrib (Oswm2) was selected from the T-DNA inserted mutant pool of rice. The midrib of the leaves in the mutant, except for the flag leaves, is white and the blade close to the white midrib is etiolated. Traits investigation of Oswm2 indicated that except the effective tillers per plant, the plant height, panicle length et al. all decreased. Except No. of effective tillers per plant, other traits of Oswm2 have significant difference compared to ZH11 by T-testing.Genetic analysis indicated that this mutant trait was controlled by a recessive nuclear gene. To map the 0sWM2 gene, an F₂ population was constructed by crossing mutant Oswm2 with 02428. The OsWM2 locus was preliminarily located between the SSR molecular markers RM21478 and RM418 on chromosome 7 with the distances of 8.7 and 15.9 cM, respectively.