Abilities of Trichoderma Species to Persist within Maize (Zea mays) Stem Long after Inoculation

Abstract

Different Trichoderma species were examined for their abilities to persist within the maize (Zea mays) stem at different points above and below inoculation points. Different Trichoderma species were isolated from different parts of the maize (Z. mays) plant and its rhizosphere. They were later sent to International Mycological Institute, England for identification. Maize seeds (DMR-LSRW) were planted in pots in the screenhouse. Four weeks after planting, each of the Trichoderma species was inoculated into the stems of the potted plants at the 2nd internodes using the toothpick method. Toothpicks dressed with sterile distilled water served as control. Cut sections of the inoculated stems were examined for presence or absence of the inoculated Trichoderma species at different points far from the inoculated point in the upper and lower internodes after 2, 3, 4, 5 and 6 weeks of inoculation. Ten Trichoderma species were identified; these include five strains of T. pseudokoningii, three strains of T. harzianum, T. hamatum and T. longibrachiatum. All the Trichoderma species were able to move within the stem tissues into the upper and lower internodes. All of them were re-isolated at distant points from inoculation point in the upper and lower internodes even after 6 weeks of inoculation. T. pseudokoningii strain 2 and T. harzianum strains 1 to 3 had the best endophytic movement into the upper and lower internodes. T. hamatum and T. longibrachiatum had the weakest movement into the upper and lower internodes. All the Trichoderma species could thus be said to possess the abilities to persist (endophytic capability) within the maize (Z. mays) stem. T. pseudokoningii and T. harzianum could also be said to be among the best species in the genus Trichoderma with good prospect of biocontrol potential.