Identification of natural variants affecting chlorophyll content dynamics during rice seedling development

摘要

Seedling vigour is an important characteristic in relation to crop growth and yield. Traits such as photosynthetic capacity and chlorophyll content contribute significantly to seedling establishment at the early growth stage in various crop species, including rice. A diverse panel of 227 rice varieties from several countries was evaluated to determine chlorophyll contents at multiple time points during the seedling stage using a soil-plant analysis development (SPAD) meter, a non-destructive portable device. Using new statistical approaches, several chromosomal regions associated with variations in chlorophyll content in the third leaf at 13, 16 and 19days after imbibition were detected. A single nucleotide polymorphism (SNP) cluster on the end of chromosome 11 was significantly associated with the onset of leaf senescence. This region was enriched with genes related to cell death and the stress response. We have identified rice germplasm showing delayed-senescence phenotypes, these could be suitable donors and genetic resources for breeding, and the use of significant SNP markers associated with these traits could enhance the efficiency of their selection in breeding programmes.