为提高链霉菌菌株LG-9发酵液的抑菌活性,在单因素试验的基础上,利用Minitab软件中的Plackett-Burman设计和响应面分析,以发酵液对棉花黄萎病菌(Verticillium dahliae)的抑菌圈大小为响应值,对链霉菌LG-9的液体发酵条件进行优化。结果表明,菌株LG-9的最佳发酵条件为250 m L三角瓶装样量101.19 m L、培养基初始p H 7.2、接种量7.5%、温度31.32℃、转速160 r/min和摇培时间69.02 h。在此条件下的抑菌圈直径大小为22.45 mm,较未优化前提高10.43%。
[ Objective] The paper was to study the relationship between temperature and development of Potosia brevitarsis Lewis. [ Methods] Six constant tem- peratures （21, 24, 27, 30, 33 and 36 ℃ ） were set in the laboratory to study developmental threshold temperature and effective accumulated temperature of P. brevitarsis. [ Result] The developmental durations of various states of P. brevitarsis were shortened with the increasing temperature ranged from 21 ℃ to 36 ℃ ; the developmental rates were accelerated with the increasing temperature. The developmental threshold temperatures of egg, larva, pupa and pre-ovipesition of adult were estimated to be 12.79, 9.15, 14.86 and 13.80 ℃, respectively; the effective accumulated temperature were 136.25, 3 031.31,308.92 and 98.35 d · ℃, respectively. The developmental threshold temperature and effective amcumulated temperature for one complete generation were 9.96 ℃ and 3 628.73 d · ℃, re- spectively. Combined with meteorological data, the theoretical generation number of P. brevitarsis occurred in Shihezi was presumed to be one per year, which was basically coincided with actual occurrence generations in fields. [ Conclusion] The paper provided theoretical basis for effective control against P. brevitarsis.
Liu ZhengSun YanChen BingZhang XuekunWang ShaoshanLi Guoying
