| Cucumber is a kind of high nutritional value and very popular vegetable, it has an important role in the supply of vegetables. Cucumber cultivation has a long history, and it is the world vegetables, widely cultivated all over China. Aphid is major pests to plants, it cause great losses to agricultural production, The study of resistance to aphid is one of the hot topics in the field of biology. In the process of comprehensive control of aphids, breeding and planting of aphid-resistant cucumber varieties is one of the most economical and the most effective measures to control aphids. In order to further breed new cucumber varieties with high resistance to aphids, and provide theoretical basis for the identification of cucumber aphid-resistance,we had this test. According to the ratio of aphid method, the hairy cucumber( an ordinary cucumber) was used as the control of less anti-aphid ability, while the glabrous cucumber( the mutant of the ordinary cucumber, its surface is smooth without hairs, with high anti-aphid ability) was used as the control of anti-aphid.The 370 home and abroad cucumber germplasm resources were taken as test materials in this test to the anti-aphid screening classification.The changes of the content of some secondary metabolites including flavone,flavonoids, tannins, total phenol, lignin content and the activity of the enzyme including phenylalnine ammonialyase(PAL), polyphenol oxidase(PPO), the type and content of volatile material in the leaves for the aphids inoculated on the leaves before and after were studied. The main results of the study were listed as the following:1. The 370 home and abroad cucumber germplasm resources were taken as test materials in this test to the anti-aphid screening classification. The results showed that: the high anti-aphid material was the glabrous cucumber, the anti-aphid material was No.118, the medium anti-aphid materials were No.311 and No.227, and the low anti-aphid material was No.321.2. The secondary metabolites and related enzyme activity of different levelanti-aphid materials were tested.The contents of flavone, lignin and the activities of PAL, PPO in the leaves of glabrous cucumber which was the high anti-aphid material were higher than those of other anti-aphid materials. The content of tannins and total phenol in the leaves of No.118 which was the anti-aphid material were highest among the anti-aphid materials, and the activity of PPO in the leaves was second only to the glabrous cucumber. The contents of tannins and total phenol, as well as the activity of PPO in the leaves of the medium anti-aphid materials No.227 were second only to No.118. The content of flavone and the activity of PALin the leaves of the medium anti-aphid materials No.311 were higher. The content of lignin and activity of PAL in the leaves of the low anti-aphid materials No.227 were second only to glabrous cucumber. The contents of flavone, tannins, total phenol, lignin as well as the activities of PAL and PPO in the leaves of the anti-aphid materials were all higher than those of the hairy cucumber.3. The volatile materials were measured. After inoculating aphids, the volatile material species were increased than before. The mainly related volatile substances of aphid resistance were 1-hexanol, 3-hexenal, Cis-3-hexene-1-ol,(E)-3-Hexen-1-ol acetate,ocimene. 1-hexanol,3-hexenal had the attraction effect to aphid. The decrease of these substance contents after inoculating aphids exhibited the effect of repelling aphids.All cucumber materials exhibited the effect of repelling aphids. Cis-3-hexene-1-ol,(E)-3-Hexen-1-ol acetate can attract natural enemies of the aphids. After inoculating aphids, the rise of these substance content,achieved the purpose of anti-aphid. In the glabrous cucumber, No.118 of seedling stage and No.227 of fruiting period stage, ocimene were detected, which can repel pests. The resistances to aphid of glabrous cucumber, No.118 and No.227 have relationship with ocimene. |
PDF Full Text Request