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The leaf blight disease caused by Lasiodiplodia theobromae is an important foliar disease in coconut that results in a yield reduction of 10–24 per cent in Tamil Nadu, India. In the present study, five Trichoderma viride isolates, Pseudomonas fluorescens and Bacillus subtilis strains were isolated from the coconut rhizosphere and tested against L. theobromae. P. fluorescens Pf1, B. subtilis (Km1) and T. viride (TNAU) isolates were found highly effective against the leaf blight pathogen under in vitro conditions and hence, all the three antagonists were combined together to develop microbial consortia and tested against leaf blight disease under field conditions. Soil application of microbial consortia formulated using talc as a carrier material at 150 g (50 g each) and 300 g (100 g each) doses at different intervals (quarterly, half-yearly and annually) was evaluated for three years from 2011 to 2013. Among the treatments, the fungicide carbendazim was found to be the most effective against coconut leaf blight. Among the treatments with bioagents, soil application of microbial consortia @ 300 g+5 kg of farm yard manure at quarterly interval/palm/year was the best treatment which was followed by the treatment with TNAU Bacillus subtilis (Bs1) mixture in two locations. Confirmatory results were obtained in similar experiments carried out at two different locations during 2013–2014, too.
Because of the need for renewable energy resources, cellulose, which can be enzymatically hydrolyzed to glucose, has drawn lot of attention during the past decade. However, the process of cellulose conversion using cellulase is not yet economically feasible because of the high cost of enzymes. Factors influencing the cellulase production of Trichoderma koningii using both acid and steam treated sugar cane bagasse and rice straw as carbon sources were investigated. The highest levels of cellulase activities were obtained using a culture medium containing urea and (NH4)2SO4 together as nitrogen sources at 0.217% and 0.241% for both carbon sources. When the culture medium was supplemented either with 0.5% Tween 60 or Tween 80, the rate of cellulase production was increased considerably. Maximum levels of both filter paper and CMC-ase activities produced on both media were obtained at 25 °C and 100 r.p.m., while the highest level of â -glucosidase production was obtained at 30 °C and 200 r.p.m.
Trichoderma species isolated from soil was investigated for ability to control wilt disease of tomato seedlings in sterile potted soil. The roots of four weeks old tomato seedlings were treated with different spores concentration (103/106 spores/ml) of Trichoderma species and placed into sterile soil inoculated with 106 spores/ml) of Fusarium oxysporum f. sp. lycopersici. The different spores concentration (103 and 106 spores/ml) of Trichoderma species prevented wilt disease development in the tomato seedlings in varying degrees. Tomato seedlings were effectively protected from infection when the pathogen F. oxysporum f. sp. lycopersici and Trichoderma species were iniculated simultaneously. Control of wilt disease was less effective when spores of F. oxysporum f. sp. lycopersici were allowed to grow one day ahead of spores of Trichoderma species. And there was no protection when the spores of F. oxysporum f. sp. lycopersici were allowed to grow two days ahead of Trichoderma species.
Isolates of Pestalozzia theae Saw. and Trichoderma spp. were collected from Bangladesh Tea Research Institute (BTRI) farm area, Bangladesh. The cultural morphology and antagonistic potentiality of Trichoderma spp. against grey blight pathogen Pestalozzia theae was studied for tea cultivation. The antagonistic potentiality of Trichoderma spp., against Pestalozzia theae showed maximum (inhibition 84.45±0.77%) after 72 hrs of inoculation under in vitro condition followed by 76.02±3.50% after 24 hrs of inoculation. This study revealed that Trichoderma strain was highly effective to control Pestalozzia theae, the causal agent of grey blight disease of tea.
Abstract
The uptake and distribution of cobalt by filamentous fungus Trichoderma viride has been studied. By means of60Co the cobalt concentrations in conidia and mycelium were determined.
In industrial production of button mushroom (Agaricus bisporus) , the green mold epidemics by Trichoderma species cause serious damage. Sampling has preformed in various stages from pili, compost, seed and soil. Trichoderma selective media and PDA were used to isolate Trichoderma species. Out of 423 isolates, three sections of Trichoderma (Trichoderma, Pachybasium and Longibrachiatum) were identified.Among these isolates, more than 350 related to Trichoderma section, 35 to Pachybasium section and 20 related to Longibrachiatum section. T. harzianum, T. virens, T. atroviride, T. citrinoviride, T. ghanens and T. longibrachiatum were identified from Agaricus bisporus . No isolates of T. aggressivum f. aggressivum and T. aggressivum f. europaeum were obtained in this study. Agaricus bisporus is Matrix Nova for T. virens . The high-resolution fingerprinting method of amplified fragment length polymorphism (AFLP) analysis and sequencing of ITS regions were used to study the genetic relationships among Trichoderma isolates. A total of 1127 polymorphic AFLP loci were obtained using 20 primer combinations. No clear trend was detected between clustering in AFLP dendrogram and geographic origin of isolated materials. According to AFLP and morphological analysis, it is concluded that application of these markers resulted the same clustering and also genetic diversity in T. harzianum aggregate group proved byAFLP, suggesting thatAFLP is suitable marker along with sequencing of conserved regions for complementary classification of Trichoderma with other phylogenetic characteristics.
Guggenheim, B., Haller, R. (1972) Purification and properties of an α-(1→3) glucanohydrolase from Trichoderma harzianum. J. Dent. Res. 51, 394-402. Purification and properties of an α
Thirty Trichoderma isolates isolated from compost, various crops and soil with roots of adjacent sites to the phosphate mines of Morocco, were tested in vitro for their potential to solubilize phosphorus from phosphate rock. The qualitative assessment of phosphate solubilization by Trichoderma isolates was performed on Modified Pikovskaya Agar (MPA) solid medium. The visual observation of the 3- and 6-day-old cultures did not show any clear zone around the colony. However, all the isolates were able to grow on the culture medium 3 days after incubation, the maximum recorded diameter was 58.6 mm for isolate TR-B 98 (3) and the minimum value was 34.8 mm for isolate TS-EM-98 (2). After 6 days, they showed good radial growth that exceeded 79.8 mm with variable appearance of the mycelial density such as the isolates TS-B 98, TS-EM-98 (1) and TR-CB 2000 (1) that presented, respectively, high, regular and low mycelial density. Also, the Trichoderma isolates produced variable number of conidia on MPA medium. Quantitative estimation on the Modified Pikovskaya Broth (MPB) liquid medium showed a variable potential of the Trichoderma isolates to solubilize phosphate when the amount of soluble phosphorus remained low in the liquid medium without the fungus (0.26 mgL−1). The maximum concentration of soluble phosphorus was 11.92 mgL−1 with percentage of soluble phosphorus equal to 95.39% recorded by the isolate TR-TB 2000 after 9 days of incubation, followed by the isolates TR-B 98 (3), TS-B 98 and TR-EM 2 respectively, 11.20, 10.47 and 9.61 mgL−1 and 89.6, 83.76 and 76.38%. In addition, treatments with Trichoderma isolates provided a lower final broth pH which varied between 6.81 for TOL isolate and 3.40 for TS-B-2000 (2) compared to initial pH (7.2). The isolates that proved potent for phosphate solubilization displayed the highest fresh and dry weights such as TR-TB 2000 (FW = 4.11 g and DW = 2.56 g), while the lowest fresh and dry weight were noted in the weakest isolates for phosphate solubilization such as T27 (FW = 1.025 g and DW = 0.58 g).
The high solubilization potential of Trichoderma isolates can be exploited for the solubilization of fixed phosphorus present in the soil, thus improving soil fertility and plant growth.
A method for measuring enzymatic activities of the Trichoderma viridae cellulase complex is described. The LKB 2277 Thermal activity monitor and a flow-mix mode were used. Enzymatic activities of samples of a crude cellulose complex have been determined using three substrates: cellobiose, carboxymethyl cellulose (CMC) and xylan. Some kinetic constants for cellobiase activity have been evaluated from the obtained results. A process of the end-product inhibition of cellobiase resp. carboxymethyl cellulase activity by glucose has been observed too.
Fourteen strains of Trichoderma spp. were isolated from Algerian desert soils and assessed for their antagonistic activity against Fusarium crown and root rot of wheat. Biocontrol efficiency of Trichoderma spp. was studied by in vitro and in vivo based bioassay against three pathogenic species: F. culmorum, F. graminearum and F. verticillioides. In vitro based bioassay (dual culture) results obtained with all Trichoderma spp. isolates showed significant decrease in colony diameter of Fusarium species compared to the control. The highest percentages of reduction in colony diameter were obtained with T. harzianum Thr.4 causing a growth reduction of 70.68%, 67.05 and 70.57% against F. culmorum, F. graminearum and F. verticillioides, respectively. All Trichoderma spp. isolates were able to overgrow and sporulate above F. culmorum colonies but no overgrowth was observed with F. graminearum and F. verticilliodes. The seed treatment by Trichoderma spp. isolates before sowing in a soil already infested by the pathogens led to a significant decrease of disease severity compared to the untreated control. The highest disease index decrease (>70%) was obtained with two isolates of T. harzianum (Thr.4 and Thr.10) and T. viride Tv.6 against the three fungal pathogens. Lytic enzymes production by Trichoderma spp. isolates was tested in liquid cultures containing fungal cell walls of each pathogen as sole carbon source. Higher levels of protease and chitinase activities were induced by hyphal cell walls of F. graminearum than cell walls of F. verticillioides and F. culmorum. T. harzianum Thr.4 exhibited the highest enzyme activities with hyphal cell walls of F. graminearum and F. culmorum. However, in the medium amended with cell wall of F. verticillioides, maximal lytic activities were recorded for T. viride Tv.6.
