DROUGHT RESISTANCE: GENETIC APPROACHES FOR IMPROVING PRODUCTIVITY UNDER STRESS

摘要

Drought and scarcity of water for irrigation severely limit wheat productivity in manydifferent environments around the world. Wheat breeders have made significant progressin adapting cultivars to water limited conditions, even though the genetic control ofdrought tolerance and water-use-efficiency (WUE), the two primary mechanisms ofadaptation to moisture deficit, are not well understood. There are a number of options available to plant breeders for improving the productivity of wheat under moisture stress. These include: (1) analysis of genotype x environment interaction to improveparental selection and identify key evaluation sites; (2) physiological characterization of germplasm to identify parents with complementary traits and to identify tools that will improve the heritability of selection; (3) development of reliable and repeatable drought screening methods; (4) broadened genetic variationfor drought adaptive traits (5) improved water harvesting via improved root health; (6)enhanced cultivar adaptation to moisture conserving crop management practices; and(7) identification and conservation of genomic regions that are associated with performance under moisture stress across environments and time. These options are examinedin the context of a wheat breeding program and their application to wheat improvementin water limited environments is discussed.