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 Aug;121(2):461-72. doi: 10.1111/jam.13163.
Effects of culture conditions on productivity, germinability and bioactivity of Trichoderma atroviride LU132 conidia were assessed to identify the factors affecting conidium 'fitness' (quantity and quality) and to withstand variable environmental conditions, increase conidial productivity, and perform optimum bioactivity.
The interaction effects of temperatures (20 or 30°C) vs hydrocarbon types (dextrose or sucrose in constant C : N 5 : 1) were assessed for bioactivity and colonization potential in pot experiments with ryegrass in the presence of pathogen, Rhizoctonia solani. Trichoderma atroviride produced in different culture conditions increased some growth parameters of ryegrass plant and also reduced the pathogenicity effects of R. solani. For example, Trichoderma colony produced at 20°C with sucrose increased all plant growth parameters and conidia produced at 20°C with dextrose gave the greatest bioactivity.
The bimodal population cycle in T. atroviride recurred in pot experiments in a manner similar to that previously observed in agar plates but indicating that simulated natural conditions shortened the Trichoderma life cycle. Trichoderma colonized ryegrass root system and symbiotically interacted with ryegrass and greater ryegrass colonization resulted from medium production treatment with dextrose rather than sucrose.
This study is the first report on the effects of inoculum production conditions on conidium quality of Trichoderma to colonize and to maintain populations in host rhizospheres, and also the ability to promote plant growth and suppress a soil-borne disease. The results of these experiments provide new knowledge on how manipulation of culture conditions of T. atroviride LU132 can influence conidium fitness, as a basis for optimizing commercial production of the fungus as a biological control agent.
评估培养条件对深绿木霉LU132分生孢子的产量、发芽能力和生物活性的影响，以确定影响分生孢子“适应性”（数量和质量）的因素，并使其能够抵御多变的环境条件，提高分生孢子产量，并发挥最佳生物活性。
在存在病原菌立枯丝核菌的情况下，通过黑麦草盆栽试验，评估温度（20或30°C）与碳氢化合物类型（在固定碳氮比5:1下的葡萄糖或蔗糖）对生物活性和定殖潜力的交互作用。在不同培养条件下产生的深绿木霉提高了黑麦草植株的一些生长参数，同时也降低了立枯丝核菌的致病作用。例如，在20°C下用蔗糖培养产生的木霉菌落提高了所有植物生长参数，而在20°C下用葡萄糖培养产生的分生孢子具有最大的生物活性。
深绿木霉的双峰种群周期在盆栽试验中以类似于先前在琼脂平板上观察到的方式重现，但表明模拟自然条件缩短了木霉的生命周期。木霉定殖于黑麦草根系，并与黑麦草进行共生相互作用，用葡萄糖而非蔗糖进行培养基生产处理可导致更高的黑麦草定殖率。
本研究首次报道了接种物生产条件对木霉分生孢子质量的影响，以及木霉在宿主根际定殖和维持种群数量的能力，以及促进植物生长和抑制土传病害的能力。这些实验结果为如何通过操控深绿木霉LU132的培养条件来影响分生孢子适应性提供了新知识，作为优化该真菌作为生物防治剂商业化生产的基础。
