干旱区生态环境知识资源中心

Soil salinity is a restraint that affects production and chemical quality of clover in the arid and semi-arid areas. The aim of this study is to evaluate in the field, the effect of salt stress, on the development and accumulation of polyphenols in different species of clover. Nine Moroccan ecotypes of Trifolium isthmocarpum, Trifolium scabrum and Trifolium lappaceum and the cultivar Paradana (Trifolium michelianum) were studied. Two trials were conducted in the field in two Moroccan sites: Ghich (Rabat) and Benadid (Casablanca) and were irrigated with water wells. The electric conductivity of the water in the first site was 0.56 ds m(-1) and 10.9 ds m(-1) in the second site. Grain yield, germination rate and the concentration of formononetin, daidzein and coumestrol were measured. After 5 mo of culture, ecotype L1 (T. lappaceum) recorded a significantly (P<0.001) higher germination capacity compared with other ecotypes for both trials. Its content on three tested polyphenol was significantly (P<0.01) below the limit adopted concentration: 200 ppm coumestrol, 25 ppm and 30 ppm formononetin to daidzein.