title: Characterization and mapping of novel chlorophyll deficient mutant genes in durum wheat.
abstract: The yellow-green leaf mutant has a non-lethal chlorophyll-deficient mutation that can be exploited in photosynthesis and plant development research. A novel yellow-green mutant derived from Triticum durum var. Cappelli displays a yellow-green leaf color from the seedling stage to the mature stage. Examination of the mutant chloroplasts with transmission electron microscopy revealed that the shape of chloroplast changed, grana stacks in the stroma were highly variable in size and disorganized. The pigment content, including chlorophyll a, chlorophyll b, total chlorophyll and carotene, was decreased in the mutant. In contrast, the chla/chlb ratio of the mutants was increased in comparison with the normal green leaves. We also found a reduction in the photosynthetic rate, fluorescence kinetic parameters and yield-related agronomic traits of the mutant. A genetic analysis revealed that two nuclear recessive genes controlled the expression of this trait. The genes were designated ygld1 and ygld2. Two molecular markers co-segregated with these genes. ygld 1 co-segregated with the SSR marker wmc110 on chromosome 5AL and ygld 2 co-segregated with the SSR marker wmc28 on chromosome 5BL. These results will contribute to the gene cloning and the understanding of the mechanisms underlying chlorophyll metabolism and chloroplast development in wheat.
authors.affiliation: Key Laboratory of Crop Gene Resources and Germplasm Enhancement, MOA, The National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences , Beijing 100081, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Li
authors.forename: Jizeng
authors.initials: J
authors.lastname: Jia
authors.forename: Chuan
authors.initials: C
authors.lastname: Xia
authors.forename: Xu
authors.initials: X
authors.lastname: Liu
authors.forename: Xiuying
authors.initials: X
authors.lastname: Kong
keywords: agronomic traits; durum wheat; genetic mapping; yellow-green leaf mutant