Ultrastructure, Genetic Analysis And Gene Mapping Of Albino Mutant Rice And Soft Rice In Yunnan China

â… Leaf color mutant (chlorophyll mutant) in rice has great proportion. Base on phenotypes, these mutants can be divided into albino, etiolation, viridoalbino, jade green, pale green, olivine and stripe etc. Base on development processes can be divided into lethal and nonlethal. Nonlethal mutants include variegated, leaky and conditional. In this study, the mutant is a conditional mutant, which controlled by temperature and development. Through observation, the mutant behaves albino before 3-leaf-stage (only endosperm supply energy) at low temperature (<24℃). It is an adaptability of rice (Oryza sativa L.) to cold.In the study, chlorophyll content at different phases (albino, backgreen) was mensurated, 9311 (indica) is control. As a result, chlorophyll content had only 1.2SPAD. But the chlorophyll content reached 23.6SPAD after backgreen, which approached 9311(25.3).It showed the mutant phenotype did not bring severe effect on growth.Chloroplast structure was observed by transmission electron. As a result, chloroplast can not develop normally just having many little vesicle. When the mutant became backgreen, the structure of chloroplast could resume normal like healthy chloroplast structure of 9311. It can showed that chloroplast structure of the mutant had changed at albino time.Reciprocal crossing had been done between albino mutant with different heredity background parents: 9311, HuaB, Taijing588, Taiwanxiangnuo. Seedling of F₁ behaved green, seedling of F₂ appeared separation of leaf color (albino and green). Separation ratio fitted for 3:1 (green seedling/albino seedling) by x² -test, in accordance with single gene inheritance. It showed that the albino trait was controlled by a single recessive gene, and the gene was tentatively referred to as al12. Using SSR molecular marker method, the mutant gene was flanked by SSR markers RM5068 and RM3702 on the short arm of chromosome 8 with a distance of 0.5-1.1 cM and 4.9cM, respectively.According to the result of mapping gene and genomic sequence of chromosome 8, two candidate coding sequences (CDS) were found in the whole contigs between the two close SSR markers RM5068 and RM3702 on chromosome 8 related to mutant phenotype (albino at low...