Identification And Gene Fine-Mapping Of A Stay-Green Rice Mutant

Chlorophyll is an important pigment involving in the photosynthesis in plants, and it plays an important role in the energy transfer and the energy capture in photosynthesis. A stay-green rice mutant, D101, was mutagenized from Zhonghua11by y-ray radiation. We researched phenotype identifications, genetic analysis and gene fine-mapping, high-throughput resequencing and candidate gene analysis about this stay-green rice mutant. The results are as follows:1. Phenotypic identifications:after sowing,45day, we found that mutant D101is darker green than the wild ZH11, the chlorophyll a content in the mutant is significantly elevation, compared to the wild ZH11. When the rice was mature in90day, the chlorophyll a content in the mutant is very significantly elevation.Chlorophyll b and carotenoids content are also very significantly elevation in this time. The result of agronomic traits of the stay-green rice mutant D101and the wild ZH11displayed that the grain1000-weight of the mutant is very significantly elevation, compared to the wild. Paraffin sections displayed the structure of the mutant and the wild is not different. Electron microscopy found that mutant stoma opened, while the wild stoma is closed in the same time. Transmission electron microscopy found that the mutant chloroplasts were filled with starch grains in the leaf, while the wild chloroplasts were filled with starch grains in the glume.2. Genetic analysis and gene fine mapping:through investigating ZH11×D101F2population in the field, genetic analysis indicated the stay green trait gene is controlled by a single gene. After investigating the ZH11xBaxiangzhan F2population in the field, we carried on the gene preliminary mapping. Using polymorphic primers, which are uniformly distributed in the12chromosomes.The result shows that the gene is positioned on chromosome1. Expanding populations and designing polymorphic primers, fine mapping is between molecular markers ID21-RM11860about525kp.3. High-throughput resequencing:through high-throughput resequencing of the wild ZH11and the mutant D101, we obtained genome sequence on12chromosomes. By software analysis, we found that the mutant has88kp large deletions on chromosome1, which is the same as the fine-mapping result. We are analyzing the88kp large deletions and predicting the candidate genes.