Nutrient amendments affect Trichoderma atroviride conidium production, germination and bioactivity

Publication date: Available online 10 November 2015 Source:Biological Control Author(s): Amir Daryaei, E. Eirian Jones, Travis R. Glare, Richard E. Falloon Trichoderma atroviride LU132, the active organism in two commercialised biological control products, was grown under different in vitro culture carbon to nitrogen ratios, to assess effects on conidium production, germination and bioactivity. Sucrose as a carbon source in agar-based growth media was adjusted to 4.2, 8.4, or 16.8 g/l carbon, and soy peptone as a nitrogen source to 0.03, 0.05, 0.11, 0.21, 0.42, 0.84, 1.68, or 3.36 g/l, to give C:N ratios in the growth media ranging from 5:1 to 160:1. Conidium production was greatest at 16.8 g/l carbon and least at 4.2 g/l, and was prolific at C:N 5:1, but was sparse at C:N 160:1. Mean conidium germination was greatest (68%) at 4.2 g/l carbon and least (58%) at 16.8 g/l carbon. Germination was greatest (74%) for C:N 5:1 and least (52%) for C:N 160:1. Trichoderma inhibition activity against the diseases-causing Rhizoctonia solani was also affected slightly for colonies obtained from conidia grown on media with 4.2 g/l carbon from 67% to 70% with 16.8 g/l carbon. Inhibition activity was greatest (73%) from conidia produced at C:N 5:1 and least (63%) from C:N 160:1. Low amounts of carbohydrate in growth media at C:N ratios near 5:1 were optimum for growth of T. atroviride LU132. Large amounts of carbohydrate probably repressed carbon catabolism, resulting in decrease...

Source: Biological Control - November 13, 2015 Category: Biology Source Type: research