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桔小实蝇对敌百虫抗性稳定性及再增长趋势 总被引:3,自引:0,他引:3
通过室内试验,研究了用LC50及LC90两种浓度敌百虫汰选14代建立的不同程度高抗性水平的桔小实蝇Bactrocera dorsalis抗性品系TrR50和TrR90在停止使用药剂后的抗性衰退规律,以及抗性衰退到原有水平的1/3时再用药汰选的抗性再增长规律。结果表明:两抗性品系对敌百虫抗性均不稳定,但抗性衰退速率不同,TrR90完全隔离药剂4代后,抗性已衰退至原有水平的1/3,而TrR50完全隔离药剂7代后,抗性才衰退至原有水平的1/3,但随后两品系抗性衰退均减缓,到19代后抗性均还处于低水平抗性阶段,无法衰退至敏感水平。通过对其抗性衰退趋势进行方程拟合,结果表明两品系抗性衰退均符合S型曲线模型。抗性再增长试验结果表明:桔小实蝇两抗性品系对敌百虫抗性再增长趋势不同,TrR50继续使用药剂汰选,经过6代选育,抗性迅速上升,接近原有的抗性水平,随后保持平稳增长; 而TrR90继续使用药剂汰选,经过9代选育,抗性才迅速上升,经过12代选育,抗性才接近原有的抗性水平。通过对两品系抗性再增长趋势进行方程拟合,结果表明两品系抗性再增长趋势不同,TrR50品系抗性再增长趋势符合逻辑斯蒂模型,而TrR90品系则符合二次曲线模型。 相似文献
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A putative contribution of polyamines to the control of peptidase activity expression during re-growth was studied in source organs (roots and stolons) of defoliated white clover (Trifolium repens L.). Endopeptidase activity increased in roots during the first 6 days following complete defoliation, while exopeptidase expression seemed to be restricted to the early hours of re-growth. These changes correlated with an immediate 80% decline in the content of total free polyamines, mainly represented by the diamine cadaverine. The inhibitory capacities of cadaverine and spermine were tested on enzyme activity in vitro in order to elucidate whether the endogenous polyamine level was associated with the cut-induced endopeptidase expression. Cadaverine seemed to inhibit endopeptidase activity of stolons but not root endopeptidase activity. These data support the view that polyamines may play a role in the regulation of peptidase expression in source organs of white clover during post-clipping re-growth. The existence of different endopeptidase isoforms in roots and stolons is discussed in relation to the molecular mechanisms by which polyamines may regulate their activities.Abbreviations AP
aminopeptidase
- Cad
cadaverine
- CP
carboxypeptidase
- EP
endopeptidase
- PA(s)
polyamine(s)
- Spm
spermine 相似文献
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