Plant growth-promotion and Antipathogenic fungal activity of four rhizosphere isolates of Trichoderma from southwest India | Trichoderma from india

Trichoderma has the potential to promote plant growth and is antagonistic to phytopathogenic fungi. Four Trichoderma strains were isolated from the rhizospheres of banana (Musa acuminata), nutmeg (Myristica fragrans), pepper (Piper nigrum) and tamarind (Tamarindus indica) (AMCC 1-4). Their culture extracts were assessed for seed germination, radical growth in mung bean (Vigna radiata), and root and corm development in the endangered species elephant foot yam (Amorphophallus paeoniifolius). The culture filtrate of all Trichoderma isolates significantly increased seed germination as well as enhanced the radical growth of mung bean (Vigna radiata), with the highest germination and radical growth by the AMCC 3 (90%). The AMCC 3 also enhanced root growth in yam (10 vs. 20 cm), while corm density increased by AMCC 2 (5 vs. 10). The analysis by high-performance liquid chromatography (HPLC) of culture filtrate of the AMCC 3 showed the presence of indole-3-acetic acid (IAA) (11.5 μg/ml). All isolates of Trichoderma possess phosphate solubilization, with the highest solubilization index by AMCC 1 (1.4). Culture filtrates of all Trichoderma isolates showed significant in vitro growth inhibition of the phytopathogen Agroathelia rolfsii, with the highest inhibition by the AMCC 3 (60%). On culturing Trichoderma isolates on carboxymethyl cellulose (CMC) agar for up to four days, all isolates showed a clear zone around the colonies confirming their cellulase-producing ability, with the highest production from the AMCC 3 (31.3 mm). The internal transcribed spacer (ITS) gene from AMCC 3 was sequenced and compared with the NCBI database using the BlastN program. The DNA sequence of AMCC 3 corresponds with that of Trichoderma erinaceum. This study reveals that four Trichoderma isolates from the rhizosphere of four horticulture plant species possess the plant growth promotion ability as well as growth inhibition of the phytopathogen Agroathelia rolfsii with high efficiency by T. erinaceum (AMCC 3). It qualifies to be adapted as a plant growth stimulant and biopesticide against fungal phytopathogens in lateritic loamy soils of southwest India.