Basal stem rot disease caused by the basidiomycete fungus, Ganoderma boninense is the most serious disease of oil palm in Malaysia. The disease can be identified by dry rotting of internal parts of the stem with fruiting bodies or basidiomata of the fungus occurring at the oil palm stem base. The stem lesion allows the basal stem rot disease to be distinguished from the other root diseases
(Turner, 1981).
Seven pathotypes of Pyricularia oryzae were differentiated from blast disease samples collected from 2014–2016, using eight Malaysian differential rice varieties. Pathotype P7.0 is the dominant pathotype identified (33.9%) followed by P0.0, P1.0 and P9.0 which are currently become more abundant in the field with frequency of 20.0% for P0.0, and 15.4% for both P1.0 and P9. Pathotype P7.0 was mostly isolated from MR220CL2, MR263 and MR219 rice varieties which are popular variety planted by farmers in Peninsular Malaysia. Interestingly, new emergence of pathotype P0.2 has been identified, which was isolated from a new released variety, MR284 as well as blast isogenic line IRBL 20 carrying Pi5(t) blast resistance gene. Prolong planting of more than 20 planting seasons and large scale planting of MR219 and MR220 with current varietal coverage areas of more than 90% in Peninsular Malaysia are suspected as possible reason for P7.0 become dominant. Varietal coverage of MR220CL2 and MR263 has reached about 50% might be the cause of changes in blast pathogen pathotype dominancy to P0.0, P1.0 and P9.0.
Mating studies were conducted on 78 isolates of Fusarium species section Liseola from rice, sugarcane and maize. From the crosses with tester strains of Gibberella fujikuroi species complex, 64.1% (50 out of 78 isolates) were cross-fertile with tester strains of mating populations A to E. The results of the mating studies showed that of the 50 isolates, 19 belonged to mating population A (Gibberella moniliformis), 18 to mating population B (Gibberella sacchari), 4 to mating population E (Gibberella subglutinans), 6 to mating population D (Gibberella intermedia) and 3 to mating population C (G. fujikuroi). Identification of several mating populations from rice,sugarcane and maize could be important biological entities under field conditions.
Endophytic fungi inhabit apparently healthy plant tissues and are prevalent in
terrestrial plants, especially root tissues, which harbour a wide assemblage of fungal
endophytes. Therefore, this study focused on the isolation and characterisation of
endophytic fungi from the roots of wild banana (Musa acuminata). A total of 31 isolates of
endophytic fungi were isolated from 80 root fragments. The endophytic fungi were initially
sorted according to morphological characteristics and identified using the sequences of
the translation elongation factor-1α (TEF-1α) gene of Fusarium spp. and the Internal
Transcribed Spacer (ITS) regions of other fungi. The most common fungal isolates were
species of the genus Fusarium, which were identified as F. proliferatum, Fusarium sp.,
F. solani species complex, and F. oxysporum. Other isolated endophytic fungi included
Curvularia lunata, Trichoderma atroviride, Calonectria gracilis, Rhizoctonia solani,
Bionectria ochroleuca, and Stromatoneurospora phoenix (Xylariceae). Several of the
fungal genera, such as Fusarium, Trichoderma, Rhizoctonia, and Xylariceae, are among
the common fungal endophytes reported in plants. This study showed that the roots of wild
banana harbour a diverse group of endophytic fungi.
Three isolates of Penicillium pimiteouiense were recovered from sandy beach soil samples in Penang Island, Peninsular Malaysia. All the isolates were identified based on morphological characteristics and phylogenetic analysis of internal transcribed spacer regions and β-tubulin gene. This is a first record of P. pimiteouiense in Malaysia.
Colletotrichum species are well-known causal agent of anthracnose. A study was conducted to determine the identity of Colletotrichum associated with anthracnose of mango (Mangifera indica) fruits. Thirty five Colletotrichum isolates were isolated from anthracnose lesion of two mango cultivars, Chokanan and Harum Manis. Based on the conidial morphology, two morphotypes (I and II) of C. gleosporioides were identified. Based on BLAST search of ITS regions and β-tubulin sequences, majority of the isolates showed 99-100% similarity with Colletotrichum sp. from mango and other hosts and three isolates, 100% similarity with C. asianum. From phylogenetic analysis using maximum likelihood method of combined datasets, the isolates from mango formed three clades, which corresponded to C. gloeosporioides sensu lato and C. asianum. Therefore, the present study showed that the isolates associated with anthracnose of mango belong to C. gleosporioides sensu lato and C. asianum.
A total of 33 isolates of Fusarium sp. were isolated from soil samples collected from a mangrove forest in an area in Kampung Pantai Acheh, Balik Pulau, Pulau Pinang, Malaysia. The isolates were isolated using soil dilution, direct isolation and debris isolation techniques. The debris isolation technique yielded the most isolates, with a total of 22 Fusarium isolates. Based on identification using morphological characteristics, three Fusarium species were identified: F. solani, F. oxysporum and F. verticillioides. F. solani (91%) was the most common species recovered from the mangrove soil samples, followed by F. oxysporum (6%) and F. verticillioides (3%).