不同饲用燕麦品种种子萌发期抗旱能力评价OA

To investigate drought resistance of forage oats during germination stage,four forage oat varieties,including Avena sativa cv.Zhongyan No.1,Avena sativa cv.Longyan No.3,Avena sativa cv.Danmai No.440,Avena sativa cv.Baiyan No.7,were selected as experimental materials.Germination tests were conducted using the between-paper method,and drought stress was artificially simulated with polyethylene glycol-6000(PEG-6000)solutions at concen-trations of 10％,15％,20％,and 25％,with distilled water serving as the control(CK).The influence of drought stress on germination rate,seedling length,longest initial root,and key physiological parameters of the tested oat varieties was systematically examined.The results showed that,compared with the control(CK),the germination rate of the tested oat varieties was significantly reduced(P<0.05)under 15％PEG-6000 treatment.In contrast,no significant dif-ference was observed under 10％PEG-6000 treatment(P>0.05),and seeds failed to germinate normally under 20％and 25％PEG-6000 treatments.Therefore,15％PEG-6000 was identified as the sensitive stress concentration for dis-tinguishing the germination responses of the tested oat seeds under drought stress.Furthermore,with increasing PEG-6000 concentration,seedling length,longest initial root,relative germination rate,seedling drought tolerance coeffi-cient,and primary root drought tolerance coefficient all exhibited a decreasing trend.However,the contents of soluble sugars(SS),soluble proteins(SP),and proline(PRO)increased progressively,whereas the activities of superoxide dis-mutase(SOD),catalase(CAT),and peroxidase(POD)showed variable patterns depending on the variety and treatment.Compared with CK,PEG-6000 treatments significantly increased SP and malondialdehyde(MDA)content in the tested varieties(P<0.05),and significantly enhanced POD,CAT,and SOD activities in Zhongyan No.1 and Danmai No.440(P<0.05).Based on the comprehensive evaluation using membership function analysis,the drought resistance of the tested oat varieties ranked as follows:Zhongyan No.1>Danmai No.440>Baiyan No.7>Longyan No.3.These re-sults indicated that Zhongyan No.1 possessed superior drought tolerance and was suitable for cultivation and promotion in arid and semi-arid regions.