Daryaei A, Jones E E, Ghazalibiglar H, Glare T R, Falloon R E
Bio-Protection Research Centre, Lincoln University, Lincoln, New Zealand.
Dryland Agricultural Research Institute, Kermanshah, Iran.
J Appl Microbiol. 2016 Apr;120(4):999-1009. doi: 10.1111/jam.13076.
The goal was to determine the effect of temperature, light and incubation period on production, germination and bioactivity of Trichoderma atroviride LU132 against Rhizoctonia solani.
The incubation temperatures of 20, 25 or 30°C were assessed on the production of T. atroviride conidia under constant light over a 25 and 50 days periods. The resulting conidia were also studied for germination and bioactivity. Conidium production was maximum at 25°C after 20 days. The second peak of conidium production occurred at 45-50 days. Incubation at 25°C after 15 days showed optimum production of T. atroviride LU132. Conidia produced at 30°C gave the greatest germination and bioactivity in comparison with incubation at 20 or 25°C.
This study indicates that the temperature at which conidia of T. atroviride are produced affects germination and bioactivity. Formulations based on production of the high conidia yield may not result in optimal bioactivity and there is a trade-off between quantity and quality of T. atroviride LU132 conidia. Conidium production was shown to be a continuous process, and increased under a dark/light regime. This is the first report of bimodal conidium production in a Trichoderma biological control agent (BCA), which is likely to be on 20 days cycle, and is dependent on colony age rather than abiotic factors. Conidia produced after 15 days are likely to be the most suitable for use in commercial production of this strain as a BCA.
Most studies on Trichoderma-based BCA have only shown the effect of culture conditions on the high conidia yield regardless of conidium quality. This study is the first report on conidium quality affected by principal culture conditions for Trichoderma biological control formulations.
本研究旨在确定温度、光照和培养时间对哈茨木霉LU132产生、萌发及对茄丝核菌生物活性的影响。
在25天和50天的时间内，在持续光照条件下，评估20、25或30℃的培养温度对哈茨木霉分生孢子产生的影响。对所得分生孢子的萌发和生物活性也进行了研究。分生孢子产量在25℃培养20天后达到最大值。分生孢子产量的第二个峰值出现在45 - 50天。15天后在25℃培养显示哈茨木霉LU132的产量最佳。与在20或25℃培养相比，30℃产生的分生孢子具有最高的萌发率和生物活性。
本研究表明，哈茨木霉分生孢子产生时的温度会影响其萌发和生物活性。基于高产分生孢子的制剂可能不会产生最佳生物活性，哈茨木霉LU132分生孢子的数量和质量之间存在权衡。分生孢子的产生是一个连续过程，在黑暗/光照条件下产量会增加。这是首次报道木霉生防菌中存在双峰分生孢子产生现象，其周期可能为20天，且取决于菌落年龄而非非生物因素。15天后产生的分生孢子可能最适合作为生防菌用于该菌株的商业化生产。
大多数关于基于木霉的生防菌研究仅表明培养条件对高产分生孢子的影响，而未考虑分生孢子质量。本研究是关于主要培养条件对木霉生防制剂分生孢子质量影响的首次报道。
