A STATISTICAL ANALYSIS OF GxE CONTRIBUTION TO LEAF SENESCENCE DURING GRAIN FILLING IN WHEAT

摘要

Senescence is a modification of cell/organ function (Thomas, 2003) that in annual crops such as wheat is linked to nutrient remobilization. Endogenous factors have been identified (Gregersen, 2013): mechanisms involving transcription factors, phy to hormones, source/sink relation and nutritional status. But these factors are influenced by the surrounding environment (light, nutrient or water availability, physical treatments ...). Senescence is a highly plastic trait but how (much) genotype or environment affect senescence is poorly understood. Recently, Bancal et al. (2015) linked physiological traits of healthy wheat (Triticum aestivum L.) crops to yield loss regarding disease pressure {Septorla trltici leaf blotch) in multiple environments. The relationships they described identified, inter alia, later leaf senescence without disease pressure as a potential trait raising tolerance, i.e. the ability of a crop to maintain grain yield in presence of expressed disease (Ney et al., 2013). The aim ofthe study is to quantify environmental and genetic contributions affecting the leaf senescence and their interaction in a set of unstressed (well fertilized and disease-free) winter wheat crops in France.