Allelopathy of the Root Aqueous Extracts of Pioneer Shrub Species on Alpine Forage Species in the Restoration Course of the Alpine Desertification Meadow
ZENG Kai;LIU Lin;CAI Yimin;SUN Feida;CHEN Youjun;CHEN Dongming;Animal Science and Technology College of Sichuan Agricultural University;National Institute of Livestock and Grassland Science;Institute of Qinghai-Tibetan Plateau,Southwest University for Nationalities;Sichuan Ganzi Tibetan Autonomous Prefecture Institute of Animal Husbandry Science;
We selected the two shrubs Hippophae rhamnoides and Salix cupularis as the donator vegeta-tion,which was pioneer species in the restoration process of desertification alpine meadow,meanwhile selected Festuca sinensis,Avena sativa,Elymus nutans,and E.sibiricus as the receptor vegetation.In order to find the suitable associated herb species which can co-occur with them,we compared the different effects of root aqueous extracts of the two shrubs on four different alpine forage species,including seed germination rate,seedling growth and antioxidant enzyme activities.The results showed that two kinds of root aqueous extracts of the pioneer species produced significant allelopathy effect on the four herbs and most of them indicated a tendency of inhibition under high concentration,but stimulation under low concentration.(1)Root aqueous extracts from the two shrubs facilitated significantly seed germination rate of each herb species under the 10 to 20g·L~(-1)concentration(P0.05),but subsequently it turned to inhibition with the concentration increasing.Except that seed germination of E.nutans was inhibited only under the concentration of 80g·L~(-1),and the other herb species' germination decreased significantly(P0.05).(2)The roots of F.sinensis and A.sativaseedling were absolutely inhibited by two kind of root aqueous extracts,but E.nutans only was inhibited when concentration reached 80g·L~(-1);the root aqueous extract of H.rhamnoides when concentration was 20g·L~(-1)could significantly promoted the growth of A.sativaand E.nutans' leaf and fresh weight(P0.05),while S.cupularis only promoted F.sinensis.(3)When the concentrationof root aqueous extract of H.rhamnoides was 20g·L~(-1),the activities of CAT and SOD in every kind of receptor vegetation were stimulated significantly(P0.05);when the concentration of root aqueous extract of S.cupularis was 20g·L~(-1)and 40g·L~(-1),the activities of CAT in A.sativaand E.sibiricus and SOD in F.sinensis were improved significantly(P0.05),but it inhibited the activity of SOD in A.sativaand E.nutans when concentration was 40g·L~(-1)(P0.05).Corresponding to changes in the activities of enzymes,the content of MDA reduced first and then increased.(4)According to the synthetical allelopathic index,E.nutans has best adaptation on root aqueous extracts of two shrub species,only inhibited under the concentration of 80g·L~(-1).All in all,S.cupularis facilitated the germination rate,seedling growth and the activities of antioxidant enzymes of F.sinensis and A.sativabetter than that of H.rhamnoides,and moreover H.rhamnoides was more suitable with E.nutans and E.sibiricus.
【Fund】： 教育部“春晖计划”(Z2015078);; 四川省科技厅国际合作项目(2016HH0087);四川省科技厅重点专项(2015SZ0062)
【CateGory Index】： Q945
【CateGory Index】： Q945