| In this research, CCRI58 and CRRI58Vsp which obtained by space mutation were used as the materials, CRRI58Vsp were systematically analyzed in levels of physiology, cyology and molecular biology. The resμlts were as follow:1. It wasn't yellow in cotyledon in CRRI58Vsp, the virescent phenotype app-eared from the first true leaf until the end of flowering stage. In CRRI58Vsp, From 0 to 3 days of leaf old, Relative conment of chlorophyl1-SPAD value decreased in true leaves as virescent trait aggravation, and as the leaves turned greening gradually, SPAD value of CRRI58Vsp increased from 3-5 days and remained steadily after that, then leaf turned to be. normal green from yellow in about 9 days.Genetic analysis sh- owed that virescent trait is controlled by a pair of recessive karyogene in CRRI58Vsp. Analysis of allelism indicated that CRRI58Vsp was not the same as other known 17 virescent materials in active collections of CRICAAS, CRRI58Vsp is primarily considered to be a new virescent material.2. Comparison of chlorophyll amount of CRRI58Vsp to the wildtype indicated that during the early stage of CRRI58Vsp leaf development, conment of chlorophyll and car-otenoid was lower than in wild-type, with the development of leaf, contents of chlorop-hyll and carotenoid in CRRI58Vsp increased gradually and closed to the normal level. At 3 days of leaf age, the precursor of chlorophyll in CRRI58Vsp was lower than in wild, while the contents of UrogenⅢand CoprogenⅢwere higher than control. The poss-ible reason is that the synthesis of chlorophyll was interrupted during early stage of leaf development, then the precursor of chlorophyll was affect- ed by feedback regμlation, as a resμIt, the accumμlation of precursor was increased or decreased.3.The development chloroplasts in CRRI58Vsp were slower than wild-type.In CRRI58Vsp chloroplasts of 0-3 days of leaf old were developmental abnormality. And development of chloroplasts of 3 days was lower than that of 0 day, e.g. boun- dary of cells was not clear, most of chloroplasts were close to be globμlar, chloroplast membrane was damaged severely, thylakoid membrane and grana lamellae were reduced, basal gran μle arranged irregμlarly. With the development of chloroplasts, chloroplasts in CRRI58Vsp of 5 days turned better, number of basal granμle and grana lamellae increa-sed, grana lamellae structure was clear, starch grain appeared. At 7-9 days leaf old, theμltrastructure of chloroplasts in CRRI58Vsp were similar to that of wild-type,and the changes ofμltrastructure of chloroplast in CRRI58Vsp were similar to that of pigment con tent during the greening process.4.Differential gene expression analysis of 3,5 and 7 days was performed using cDNA-AFLP technology in CRRI58Vsp and wild type,64 pairs of primers were screened, 15 bands per lane in everold,6000 bands were amplified; 79 TDFs were obtained,12 of them involve in photosynthesis, chloroplast development and light signal transduction. These TDFs may relate to the virescent trait of CRRI58Vsp.5. Chlorophyll synthetase- GhCHLG1and GhCHLG2 were obtained by E-clone met-hod. Analysis showed that there were 5 mutated base in GhCHLG2 gene compared with GhCHLG1sequence, leading to change of 3 amino acids. Expression profile analysis was performed by QRT-PCR. The gene expression amount in CRRI58Vsp is lower during early stage compared with its control of 0 day leaf old, and up-regμlated at 3 days leaf old, after that the content of gene of chlorophyll synthetase was higher than or equal to CRRI58; the gene expression pattern in wild type is:up-regμlation- down-regμlation-up-regμlation. The gene expression pattern was different between CCRI58Vsp and CRRI58 maybe the resμlt of base mutation, and the virescent phenotype may be caused by the base mutation in CRRI58Vsp.
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