Morphological and molecular identification of Fusarium spp. and Colletotrichum spp. isolated from infected vanilla orchid

Aims@#This study aimed to isolate and identify fungi involved in causing diseases to Vanilla planifolia as well as to study their pathogenicity level in causing disease.@*Methodology and results@#The diseased parts of vanilla plants were collected from vanilla farms located in Pahang and Sabah, Malaysia from May 2015 to May 2016. Diseases tissue transplantation was adopted to isolate the fungi for morphology identification prior to the polymerase chain reaction (PCR) amplification of internal transcribed spacer (ITS) regions using universal primers for fungi, ITS1 and ITS4. After being isolated, the fungi pathogenicity was tested on detached fresh and mature vanilla leaves. A total of 22 fungal isolates were identified, Fusarium fujikuroi and F. oxysporum were the two most recovered species, followed by Colletotrichum gloeosporioides, Fusarium sp., F. proliferatum and F. solani. Pathogenicity test revealed a significantly high pathogenicity of F. oxysporum and C. gloeosporiodes (p<0.01) on detached vanilla leaf, with high level of damage. @*Conclusion, significance and impact of study@#This study provides valuable information on fungi-associated diseases on vanilla plants grown in Malaysia and can be used for future development in disease management.

Isolation of antagonistic Trichoderma spp. against selected phytopathogenic fungi from the field soils in Kelantan

Aims: Trichoderma is a soil borne mycoparasitic fungus which comprises a number of fungal strains that act as biocontrol agent. In this present study have investigated the diversity of Trichoderma in different cultivated soils in state of Kelantan. The effectiveness of biocontrol agent of isolated Trichoderm species was evaluated against the phytopathogen of Pyricularia oryzae, Fusarium oxysporum, and Ganoderma boninense. Methodology and results: The identification experiment was carried out on the basis of morphological characteristics as colony appearance, shapes and size of conidia, the branching patterns of conidiophores and phialides. Then, the effectiveness of biocontrol agent of Trichoderma species against the pathogens was tested in plate assay experiment. A total of 11 isolates were obtained from three different cultivated soils from Jeli (J), Machang (M) and Pasirmas (P). Morphological studies data identified as two groups of Trichoderma species as Trichoderma harzianum, and T. koningii. All the isolates showed the antagonistic activity against the pathogens while T. harzianum strain THMPA1 showed highest antagonistic activity of 80.00% against P. oryzae and in T. koningii strain TKMPA3 group showed highest antagonistic activity of 69% against P. oryzae. Conclusion, significance and impact of study: Among the 11 isolates of Trichoderma, the species of T. harzianum strain THMPA1 was the best as biocontrol agent against P. oryzae. Thus, diversity of Trichoderma species study is important to find promising species isolation of Trichoderma species which will be influenced in future to sustainable crop production and maintain green environment.