牧草型苇状羊茅种质抗旱性评价研究OA

This study aimed to identify drought-tolerant resources from wild germplasm of tall fescue(Festuca arundinacea).Four accessions(three wild and one cultivated)previously selected from over 300 wild germplasm accessions,together with the forage-type check cultivar 'Fawn'(control),were subjected to two water treatments:normal water supply(70%-80%of field capacity)and drought stress(30%-40%of field capacity).The results showed that significant differences in drought tolerance existed among the germplasm accessions at the seedling stage,with the membership function U values ranking as follows:CF017317(0.823)>Fawn(0.658)>CF017326(0.646)>CF017267(0.423)>CF017242(0.360).Analy-sis of the physiological mechanisms underlying drought tolerance revealed that CF017317 maintained a high net photosynthetic rate at the late stress stage(21 d)and balanced antioxidant enzyme activities,indicating a drought tolerance strategy involving synergistic regulation of osmotic adjustment,photosynthetic stabil-ity,and antioxidant defense,with CF017317 showing the best overall drought tolerance.The accession CF017317,which exhibited the strongest overall drought tolerance,is a high-quality breeding material for developing new drought-tolerant forage varieties of tall fescue.