Relationships between phenotypic variation in osmotic adjustment, water-use efficiency, and drought tolerance of seven cultivars of Lotus corniculatus L.

摘要

Lotus corniculatus L. is a perennial forage legume species highly-adapted to growth under drought conditions. However, the genetic and physiological mechanisms involved in its adaptive capacity have not been elucidated. The role of osmotic adjustment (OA) and water-use efficiency (WUE) on the drought tolerance of L. corniculatus was studied in a greenhouse experiment. Seven cultivars of different origin were subjected to two contrasting treatments of available soil water: No water stress (NWS) and with water stress (WWS). Xylem water potential (Ψx), osmotic potential (Ψπ), pressure potential (Ψp), relative water content (RWC), stomatal conductance (g s), shoot DM production, water transpiration (T), and WUE (shoot DM/T) were measured. Water treatments significantly (P