Preliminary Study On Characteristics Of Aphid Resistant Of Different Resistance Maize Inbred Lines

Maize is one of the main crop of our country,aphid of maize is the major invasion of vermin in maize Anciently, studies on the resistance of aphid mainly focused on crops of broomcorn,wheat,cotton,fruits and vegetables like grape, capsicum and so on. Studies on aphid resistant characteristics of maize are not many, and study use the maize inbred lines as the material is even fewer.Maize inbred lines qua the important idioplasm resources of breeding by crossing,the height of it's resistance will direct affect the output of seeds make by crossing-breeding and the resistant characteristics and the output of the breeding by crossing. This test use different resistant maize inbred lines as materials, studied on the activities of kinds of key enzymes,some hypo-compound of total phenol,matter of nutrition,which were all relate to the characteristics of resistant, showed the changes direction of the content of MDA in leaves and tassel,chlorophyl and waxiness in leaves of inbred lines in different bearing phases at separate condition, and described the rules of changes of the matters mentioned above in susceptible materials at natural invaded condition. Look forward to offer reference to the appraisal of resistant characteristic and aphid -resistant breeding of maize inbred lines.The results showed that the activities of POD in leaves and tassel in different resistance to aphids of maize inbred line under isolation conditions is gradually rised as the time goes on; except very few materials, the activity of PAL increased first and then drop down, the activity of ASA-POD is the opposite, the rule of changes of the PPO activity has evidence distinction. After invaded by natural, the activities of PPO,POD at different times in leaves and tassel of the three susceptible materials significantly increased; the activities of PAL in leaves of different periods and tassel at aphid decline and death phase has increased, and the activity of ASA-POD in tassel increased at all times. The changes of enzymes were very different with the changes of the resistance at different invaded periods, and some times there are certain rules. At the isolation and natural aphid conditions among the three types of susceptible materials, the activity of PPO in leaves of 9401 was lowest at aphid decline and death phase, and the activity of PAL was lowest at aphid decline phase; the activity of PPO in tassel of 9401 was lowest at aphid decline and death phase, and the activity of ASA-POD at aphid decline phase; the activities showed that lower with the decreases of the resistance.The changes of the content of soluble protein under isolation conditions in leaves of different resistance to aphids of maize inbred line showed a current like a word of"N", and in tassel showed a"V";the content of total sugar in leaves declined quickly and then keep the leave in whole, but in tassel rise first and then fall; the content of reducing sugar in leaves showed a rising trend overall, but in tassel it showed decline first and then increase; The content of free amino acid,proline,total soluble sugar in leaves have great deal of difference for different materials, except 99028, the content of proline in tassel will decline first and then increase, the content of total soluble sugar is the opposite. Aphid infection will reduce the content of the nutrition substance in different parts of the sensitive materials at the majority of the time.The content of total phenol,flavonoid,anthocyanin in leaves of different resistance to aphids of maize inbred line under isolation condition increased gradually as growth period goes on, the content of total phenol and flavonoid in tassel increased first and then decreased, the content of tannin and the anthocyanin in tassel have great deal of difference for different materials. Under natural invaded condition, the changes of the ontent of secondary compounds in leaves and tassel of the three sensitive materials will not the same for the different of the parts and the times.The content of MDA in leaves of resistant materials under the isolation condition increased gradually as the time goes on,but there were a lot of differences in the changes of the content of chlorophyll and waxiness in leaves. Aphid infection will reduce the content of MDA in leaves of sensitive materials and increase the content of MDA in tassel most of the time ,and induce the content of chlorophyll and waxiness in leaves increased at the most of the time.