Effect of aphid invasion on physiological and biochemical indexes in watermelon seedling stage

Abstract: 【Objective】The aim of this study is to primary understand the resistant mechanism of watermelon to aphids【.Methods】Two aphid resistant watermelon materials‘Zhenmu 4'and‘KY-2'and two susceptible watermelon materials‘Zhong 10 haikang'and‘148'were choosed for study of the physiological and biochemical influences of aphids(Aphis gossypii Glover) infestation on on watermelon at the seedlingstage.【Results】The results revealed that compared with control group,the proline,MDA content and defense enzymes activities increased in all four watermelon materials and the soluble protein contents increased in all materials except‘148'with aphid infestation. But the total soluble sugar contents were significantly lower than that in the control. Meanwhile,the proline content and PAL,POD,CAT,SOD activities of the two anti-aphid materials were remarkedly higher than that in the two susceptible materials,the MDA content in watermelon‘Zhong 10 haikang'was also significantly higher than that in two anti-aphid materials,while the total soluble sugar contents in these anti-aphid materials and the soluble protein contents of‘KY-2'were remarkably lower than that in the two susceptible materials.【Conclusion】In summary,it is suggested that the contents of proline,MDA,soluble sugar and the activities of PAL,POD,CAT and SOD were closely linked with watermelon resistance to aphids,thus they could be considered as physiological biochemical indexes for watermelon resistance to aphids.