Variability in production of extracellular hydrolytic enzymes by Trichoderma spp. and induction of resistance in Gram (Cicer arietinum).

摘要

Ten isolates of Trichoderma spp. isolated from rhizosphere region of different crops were evaluated for their ability to produce extracellular hydrolytic enzymes, viz., beta -1, 3 glucanase, chitinase and cellulase enzymes with different concentrations of carbon sources, pH, and temperature levels and the induction of systemic resistance in gram seedlings. Highest chitinase and beta -1, 3 glucanase activity were observed in TR2 isolate whereas TH2 isolate exhibited highest activity of cellulase. TH1 and TH5 were the next best isolates in their chitinase enzyme activity. Similarly, TR1 and TH1 isolates followed the TR2 for beta -1, 3-glucanase activity. The activity of cellulase was highest in TH2 isolate followed by TH5 and TR2, which were statistically significant. The enzyme beta -1,3 glucanase was produce in media with pH 4.0 to 8.0 with an optimum pH 5.5. The optimum pH for chitinase and cellulase enzyme activity was recorded at 5.0. With the variable temperatures, i.e., 20, 25, 30, 35 and 40 degrees C, the enzyme activities of all three enzymes showed highest at 30 degrees C. The activities of enzymes beta -1,3 glucanase and chitinase was recorded highest at 3.0 and 4.0% concentrations of glucan and chitin, respectively whereas 0.75% concentration of cellulose showed highest cellulase activity. The highest induced resistance by Trichoderma isolates in gram seedlings, was recorded by TR1 through the increase activity of PAL and beta -1,3 glucanase and TH1 by enhance activity of peroxidase enzyme.