暗黑鳃金龟幼虫生防黄绿绿僵菌Ma130821菌株的室内培养条件的研究

Study on the culture condition for the biocontrol strain Ma130821 of Metarhizium flavoviride against the chafer of Holotrichia parallela

从云南省玉溪市塔甸镇玉米地自然罹病的暗黑鳃金龟幼虫僵虫上分离纯化获得了黄绿绿僵菌Ma130821,为了弄清该菌株培养条件,为蛴螬生物制剂开发应用提供依据,本研究在室内测定了该菌株在PDA和SDAY培养基上的生长繁殖情况及在不同pH、温度、光照条件下培养特征及产孢特性。结果表明:黄绿绿僵菌Ma130821菌株在PDA和SDAY两种培养基上均能生长,但在PDA培养基上产孢时间早于SDAY,其中在PDA和SDAY培养基上分别于第6天和9天开始产孢。在25℃时生长最好,平均直径日增量为0.24 cm/d,第4天时就开始产孢且产孢量最高,为1.091×10~7孢子/cm^2。在16 L∶8 D的光周期条件下菌落生长最快,产孢时间最早,且产孢量最大。pH 6.5最适宜该黄绿绿僵菌菌株的生长及产孢。综合以上结果,PDA培养基可用于黄绿绿僵菌Ma130821菌株的室内培养,最适培养条件为pH 6.5、25℃、16 L∶8 D。该研究结果将为蛴螬生防黄绿绿僵菌Ma130821制剂的开发提供依据。

The biocontrol strain Ma130821 of Metarhizium flavoviride for pest insect was isolated from the chafer of Holotrichia parallela Motschulsky in corn field in Tadian county of Yuxi city, Yunnan Province. A study on the culture conditions for the stain Ma130821 was conducted in laboratory in order to research and develop biological control agents for chafers. The growth and sporulation of Ma130821 was tested on different culture medium under different pHs, temperature and photoperiods. The results showed that the strain Ma130821 can be cultured on PDA and SDAY medium, but the sporulation on PDA was earlier than on SDAY, which was on the 6 th day after the culture. The optimal temperature for the growth of Ma130821 on PDA medium was at 25℃, the daily increase rate of colony diameter was 0. 24 cm/d, it produced spores on the 4th day after the culture and with a maximum sporulation of 1. 091 ＆#215; 107 spores/cm2. The most rapid growth rate of colony, the earliest and the greatest sporulation was at the photoperiod of 16 h light and 8 h darkness. The optimal pH for the growth of Ma130821 was 6. 5. Based on the above results, the PDA medium is suitable for the culture of Ma130821 , the optimal condition for its growth and development was pH6. 5 , 25℃ and 16 h photoperiod. All the results will provide a theoretical base for the development of biological control agents for chafers.