| In recent years,the situation of cadmium(Cd)pollution in farmland in China is severe,seriously affecting the growth of crops and the safety of agricultural products,threatening human health.In this study,a pot experiment was conducted with winter wheat as a material to study the effects of Cd stress(3mg·kg-1)on the physiological characteristics and yield different wheat varieties(Pingan 8 and Bainong 160).The results are as follows:1.Cd stress reduced the photosynthesis rate(Pn),intercellular CO2 concentration(Ci),stomatal conductance(Gs)and transpiration rate(Tr)of Pingan 8 and Bainong 160 leaves,and Pingan 8 decreased.The magnitude is higher than that of Bainong 160.2.Cd stress increased the activities of antioxidant enzymes(SOD,POD and CAT)and MDA content of Pingan 8 and Bainong 160.Under Cd stress,Bainong 160 had higher antioxidant capacity than Pingan 8.3.Cd stress reduced the contents of GA3,IAA and ZR in Pingan 8 and Bainong 160,and increased the ABA content of Ping’an 8 and Bainong 160.In the Cd treatment,the GA3,IAA and ZR contents of Bainong 160 leaves were higher than that of Pingan 8,and the ABA content was significantly lower than that of Pingan 8.4.Cd stress reduced the yield and biomass of Pingan 8 and Bainong 160,and the yield and biomass of Pingan 8 decreased more than that of Bainong 160.In the Cd treatment,the yield and biomass of Bainong 160 were higher than that of Pingan 8.5.Compared with Pingan 8,Bainong 160 can accumulate more Cd content because of its strong ability to absorb and transport Cd.According to the grey correlation analysis,the gray correlation degree between Bainong 160 and Cd content,biomass,photosynthetic parameters,antioxidant enzyme activity and hormone content level was 0.90,while the gray correlation degree of Pingan 8 was 0.76.Compared with Pingan 8,Bainong 160 is more tolerant to Cd.Under Cd stress,Bainong 160 has high antioxidant enzyme activity,MDA content,GA3,IAA and ZR content,yield and strong Cd absorption and transport capacity,so it has high Cd resistance.Under the stress of Cd,Pingan 8 had a large decrease in photosynthetic parameters,higher MDA content,lower GA3,IAA,ZR content,antioxidant enzyme activity and yield,therefore,its Cd resistance was poor. |
