嘧菌酯提高马铃薯耐旱性的生理基础研究

采用盆栽法,以抗旱性不同的3个马铃薯栽培种为研究对象,于播种前以25%嘧菌酯悬浮剂为沟施药剂处理(A),正常浇水为对照(CK,土壤体积含水量θw:60%~70%),干旱为水分处理(D,θw:30%~40%),以及干旱与药剂共同处理(A-D)。通过测定叶片光合参数、抗氧化酶活性、丙二醛(MDA)和脯氨酸含量及马铃薯单株产量与品质等指标,探讨施用嘧菌酯对改善马铃薯干旱胁迫耐受性的生理基础。结果表明:嘧菌酯可有效增强马铃薯叶片净光合速率和气孔导度;在正常水分条件下,施用嘧菌酯可引起叶片过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)活性的增强,具有延缓植株衰老的作用;在干旱胁迫条件下施用嘧菌酯可降低叶片MDA和脯氨酸含量,提高植株耐旱性。A较CK处理青薯9号、陇薯6号和大西洋单株产量分别增加30.74%、59.87%和5.90%,A-D较D处理分别增产15.17%、43.43%和16.49%;A处理青薯9号、陇薯6号和大西洋综合品质得分分别为1.184、2.856和0.621,A-D处理分别为-1.112、-0.240和-0.349。可见,嘧菌酯有利于干旱胁迫条件下马铃薯块茎品质的提高。

Physiological basis of potato drought tolerance induced by azoxystrobin

In this study,three potato cultivars with different drought resistance were used as the testing materials in potted-experiments.Azoxystrobin was used as the ditch treatment chemicals(A)before planting.The group with full irrigation was the control(CK,soil volume water content θw:60%-70%).The drought group was the one with water stress treatment(D,θw:30%-40%).The group(A-D)was treated by both drought and azoxystrobin.The physiological basis of the potato drought tolerance improvement induced by azoxystrobin was investigated by measuring leaf photosynthetic parameters,antioxidant enzyme activities,malondialdehyde(MDA)and proline content,potato yield per plant and tuber quality.The results showed that azoxystrobin could effectively enhance the photosynthetic rate and stomatal conductance of potato leaves.Under full irrigation conditions,application of azoxystrobin could increase the activities of CAT and APX,which played a role in the delay of the senescence of plants.Under drought stress conditions,the accumulation of MDA and proline content in leaves was reduced,resulting in an increase in drought tolerance of plants.Azoxystrobin respectively increased the yields of Qingshu No.9,Longshu No.6 and Atlantic by 30.74%,59.87% and 5.90%,compared to those of the CK.And A-D treatment respectively increased the yields of Qingshu No.9,Longshu No.6 and Atlantic by 15.17%,43.43% and 16.49%,compared to those of the D group.In addition,the comprehensive quality scores of A Qingshu No.9,Longshu No.6 and Atlantic respectively were 1.184,2.856,0.621,and A-D respectively were-1.112,-0.240,-0.349.It can be seen that azoxystrobin was beneficial to the improvement of potato tubers quality under drought stress.