ÃÞ »¨ ѧ ±¨ Cotton Science 2009£¬21(1)£º57-63
Resistance and Relevant Mechanism to Aphis gossypii Glover of Main Cotton Varieties in Xinjiang Abstract£ºThe cotton aphid, Aphis gossypii Glover( Homoptera: Aphididae ), is one of the major destructive pests on cotton in Xinjiang , China . In 1994, 1997, 2001 and 2003, A. gossypii happened in a large scale in cotton production area in Xinjiang. Insecticides are the only efficacious method of aphid controlling. Although the use of insecticides can be a quick and easy way, the ideal time to spray is not well defined. Insecticides also have many adverse effects such as killing beneficial insects, environmental contamination, and increased production costs. A. gossypii populations may resurge when applications of insecticides are poorly timed or applied. Screening cotton varieties resistant to the aphid is a long-term solution. There were no reports about cotton cultivars with resistance to aphid in Xinjiang, currently. This research deals with the relationship between some morphological characteristics and biochemical substances with the resistance to the cotton aphis in nine main cotton varieties in Xinjiang. The results showed that there were significant differences in resistance to A. gossypii among different varieties, with Xinhai 21 as the most resistant one, and CCRI 35 and 81-3 as susceptible ones. The wax content and hair density were positively correlated with the resistance to A. gossypii , by influencing aphis feeding behavior. Both free gossypol and soluble sugar were also in positive correlation with the resistance, while the content of tannin was in negative correlation (R=0.984). The high content of glutamic acid was an indicator of high resistance to A. gossypii (R=0.884). However, contents of total nitrogen and amino acids were not associated with the resistance to A. gossypii by stepwise regression analysis and correlation analysis, which indicated that many factors contributed to the resistance to A. gossypii.
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