Working group session:
Germplasm and Genetic Stocks
Presentation type:
oral
Authors:
song, meizhen; fan, shuli; pang, chaoyou; li, haijing; yu, shuxun
Presenter:
song, meizhen; fan, shuli; pang, chaoyou; li, haijing
Correspondent:
yu, shuxun
Abstract:
Virescent leaves are an important character of plant that can be inherited in cotton (Gossypium hirsutum L.). Most of which suggested that this trait was controlled by one recessive gene in nucleus. It was well known that this genetic mutation could be generated by nature condition, physical treatment (for example, γ-irradiation) and chemical treatment (for example methylnitrosourea and ethyl methanesulfonate) and tissue culture. Here we reported identification of a virescent mutation (vsp) after exposing the upland cotton (Gossypium hirsutum L.) CCRI58 seeds in space environments. vsp mutant was characterized at the morphological, agronomic, cellular and genetic levels. vsp mutant showed an earlier virescence and specific only to true leaves. Agronomic traits of vsp mutant, such as plant height, number of bolls, boll weight, yield and fiber quality were significantly lower than those of CCRI 58. Chlorophyll level, carotenoid level and photochemical efficiency of vsp mutant true leaves were significantly lower compared to CCRI 58 at young leave stage. Anatomical studies of chloroplasts showed that vsp mutant lacked grana in the thylakoids of the mesophyll cells at young leave stage, while CCRI 58 showed normal grana in the thylakoids of the mesophyll cells at young leave stage. This indicated that chlorophyll and carotenoid levels were related with chloroplast structure. In order to clone the candidate genes of the virescence trait, F2 segregation population was built by crossing parents between vsp as materal and TM-1 as paternal. The principium gene mapping of Virescent mutation was made by getting polymorphic markers. The fine gene mapping of virescent mutation was made by getting polymorphic markers from F2 large segregation population. The differentially expressed genes are identified by bioinformatics analysis of RNA transcriptome sequencing data. It would be explained the molecular mechanism of the virescent mutation and application of virescent mutant in cotton breeding programs.
Key words: the short season cotton, virescent mutation (vsp), molecular mechanism, the principium gene mapping, the fine gene mapping, the differentially expressed genes.