Fungi Associated With Different Parts of Cotton Seed

Seed samples with highest (CB10), lowest (CB8), moderate fungal frequency (CB3) and randomly selected seeds from all varieties (CB1-14) were used. A total of 14 species of fungi, namely Aspergillus flavus Link, A. fumigatus Fresenius, A. niger Van Tiegh, Curvularia lunata (Wakker) Boedijn, Colletotrichum gloeosporioides Penz & Sacc, Fusarium nivale (Fr.) Sorauer, F. oxysporum Schlechtendal, F. fujikuroi Nirenberg, Penicillium aculeatum Raper & Fennell, Penicillium citrinum Thom, Rhizoctonia solani Khun., Rhizopus stolonifer (Ehrenb.) Vuill., Syncephalastrum racemosum Cohn and Trichoderma viride Pers. were found to be associated with seed parts of different varieties of cotton. The maximum ten species of fungi were isolated from seed coat. The most prevalent fungus was Rhizopus stolonifer which was found in all the parts of all the varieties of cotton seeds examined. Out of the 14 isolated fungi, Aspergillus flavus, A. fumigatus, A. niger, C. lunata, C. gloeosporioides, F. nivale, F. oxysporum, F. fujikuroi, Penicillium aculeatum, R. solani, R. stolonifer, S. racemosum and T. viride were found to be external and Aspergillus flavus, A. fumigatus, A. niger, C. lunata, F. nivale, Penicillium citrinum and R. stolonifer were internal seed borne fungi. Aspergillus flavus, A. fumigatus, A. niger, C. lunata, F. nivale and R. stolonifer were isolated as both external and internal seed borne fungi. Dhaka Univ. J. Biol. Sci. 29(2): 237-244, 2020 (July)

Pathogenic potentiality of fungi associated with the seeds of different cotton (Gossypium hirsutum L.) varieties in Bangladesh

A total of 24 species of fungi, namely Aspergillus flavus Link, A. fumigatus Fresenius, A. niger (Type 1 and Type 2) Van Tiegh, A. ochraceus K. Wilhelm, A. nidulans Eidam, Aspergillus sp.1, Aspergillus sp.2, Aspergillus sp.3, Curvularia lunata (Wakker) Boedijn, Colletotrichum gloeosporioides Penz & Sacc, C. gossypii Southw., Chaetomium globosum Kunze., Fusarium nivale (Fr.) Sorauer, F. moniliforme J. Shelden, F. oxysporum Schlechtendal, F. fujikuroi Nirenberg, Mucor sp. P. Micheli ex L., Penicillium sp.1 and sp.2 Link, Rhizoctonia solani Khun., Rhizopus stolonifer (Ehrenb.) Vuill., Rhizomucor sp. Lucet & Costantin, Syncephalastrum racemosum Cohn and Trichoderma viride Pers. were found to be associated with the seeds of 14 varieties (CB 1- CB 14) of cotton. Out of these 24 fungal species, nine were found to be pathogenic to cotton. They were Aspergillus flavus, A. niger (Type 1), Aspergillus sp. 1, Colletotrichum gloeosporioides, Curvularia lunata, Fusarium nivale, F. moniliforme, Mucor sp. and Rhizoctonia solani. These pathogenic fungi had remarkable effect on seed germination, vigor index, root-shoot length and mortality of cotton seedlings. The germination percentage of control seeds was 88 but because of the presence of pathogenic fungi the rate showed considerable reduction in all the varieties and it varied from 20 to 82%. Among the nine fungal isolates Rhizoctonia solani showed maximum reduction in seed germination. Aspergillus flavus, Colletotrichum gloeosporioides and Fusarium moniliforme also caused near about 50% reduction in seed germination. Mortality percentage of control seedling were also less (6) whereas, in inoculated seeds it was higher and varied from 7 - 23%. Root- shoot ratio of control seedlings was high but less in inoculated seedlings. The vigor index of control plant was high (1548.8) but less in inoculated plants. The lowest vigor index was noticed for Rhizoctonia solani (202.0) and highest for Aspergillus sp. 1(1213.6). Results indicated that Curvularia lunata and Rhizoctonia solani showed a greater impact in reduction of cotton seed germination and vigor index. Dhaka Univ. J. Biol. Sci. 29(1): 107-115, 2020 (January)

EFFECTIVENESS OF DIFFERENT FUNGICIDES AGAINST PREDOMINANT AND VIRULENT FUNGUS FUSARIUM NIVALE THE CAUSE OF MANGO MALFORMATION DISEASE

Fusarium nivale (Fr.) Ces. a recently reported fungus of mango malformation disease (MMD)is a predominant and virulent fungus in mango orchards of Sindh, Pakistan. In the current study in vitro and in vivo attempts were made with commercial fungicides to reduce the severity of F. nivale. Mycelial growth of F. nivale was significantly inhibited at low and high doses of Thiophanate methyl and Fosetyl- Aluminium. Metalaxyl+Mancozeb and Mancozeb also reduced growth of fungus at their high doses (6.830 and 11.900mm), respectively, as compared to Copper oxychloride (18.083 mm) and control (40.750 mm). Thiophanate methyl and Fosetyl- Aluminium significantly reduced infection in Desi, Almas and Dusheri to 16.60 and 19.00%; 17.60 and 19.80%; and 20.60 and 22.00% after first spray, with decreased percent of malformation 72.33 and 68.33%; 71.11 and 67.54%; and 67.81 and 65.62% and over untreated control. The second spray of Thiophanate methyl and Fosetyl- Aluminium fungicides completely inhibited infection of F. nivale, and 100.0% reduction in malformation disease in Desi, Almas, and Dusheri as compared to Metalaxyl+Mancozeb (78.73, 73.84, 72.64%) and Mancozeb (73.65, 73.69, 69.41%), Copper oxychloride and in control. The application of Thiophanate methyl and Fosetyl- Aluminium would be useful in integrated management of MMD.

Fungi Associated With Common Spices In Bangladesh

Association of fungi in chili (Capsicum fruticance L.), coriander (Coriandrum sativum L.) and turmeric (Curcuma longa L.) was investigated. A total of 19 species of fungi under ten genera and one sterile mycelial fungus was isolated from the three spices. Out of ten genera three belong to Phycomycetes, one genus belongs to Ascomycetes and rest belongs to Deuteromycetes. The most frequent contaminants of the spices were Aspergillus niger van Tieghem, A. flavus Link, Fusarium nivale, Pestalotia sp. and Rhizopus sp. Dried fruits of the spices showed maximum number of fungal association in comparison with the respective commercial brand powder samples. Out of three plant extracts. A. sativum was found to inhibit the growth of all the test isolates at all concentrations. Asiat. Soc. Bangladesh, Sci. 40(2): 179-186, December 2014

Interaction between some fungi living on cereal seeding material

The biotic relations were evaluated between saprophytic fungi genera <i>Fusarium</i> and <i>Helmithosporium</i>. Most of the saprophytic fungi restricted the development of <i>Helmihthosporium sativum</i> and <i>H. triseptatum</i> more than that of <i>Fusarium nivale</i> and <i>F. avenaceum. Sordaria fimicola</i> was the only fungus which restricted the growth of <i>Helminthosporium sativum, H. triseptatum, Fusarium nivale</i> and <i>F. avenaceum</i>.

Monographella nivalis on the leof sheath of winter Triticale

Monographella nivatis (Schaffnit) Mülier was found in 1983. Punctiform perithecia were scattered irregularly on the bleached tissues of the sheaths at the beginning of July. The ascospores were mostly mono- or bicellular. The cultures from the ascospores were producing typical conidia of the fungus <i>Fusarium nivale</i> (Fr.) Ces. in exposure to light were successfuly cultivated on leafs of the wheat agar.

Phylloplane mycoflora of Gerbera spp. and their Pathogenic potentiality

Two types of symptoms, blight and anthracnose, were recorded on two species of Gerbera viz. Gerbera aurantiaca L. and Gerbera viridifolia L. The most common fungal species isolated from Gerbera spp. were Alternaria citrii, A. tennuisssima, Aspergillus flavus, A. fumigatus, A. niger, A. terreus, Bipolaris hawaiiensis, Chaetomella raphigera, Cladosporium cladosporoides, Colletotrichum capsici, C. coffeanum, C. dematium, C. gleosporioides, C. lindemuthianum, C. musae, C. orbiculare, Colletorichum sp.1, Colletotrichum sp.2, Colletotrichum sp.3, Colletotrichum sp.4, Curvularia clavata, C. lunata, Fusarium nivale, F. semitectum, Phomopsis sp., Penicillium sp., Pestalotia sp., Rhizopus stolonifer, Trichoderma viride, one cleistothecial ascomycetes and one sterile fungus. The frequency percentage of association of Colletotrichum spp. with Gerbera spp. was higher than any other fungi. Bipolaris hawaiiensis is a new record for Bangladesh. Among the isolated fungi Alternaria citrii, A. tennuissima, Colletotrichum capcisi, C. dematium, C. coffeanum and Curvularia clavata were found to be pathogenic to Gerbera plant. DOI: http://dx.doi.org/10.3329/jbas.v37i2.17562 Journal of Bangladesh Academy of Sciences, Vol. 37, No. 2, 211-217, 2013

Development of resistance to Microdochium nivale in winter wheat during autumn and decline of the resistance under snow

The effect of autumn climate on the development of resistance to pink snow mold (Microdochium nivale) in winter wheat was estimated in mid-December. Changes in resistance over time under snow cover were also determined. Resistance in December was closely correlated with the accumulated degree-days above 0 °C from sowing. The number of days of incubation at which 50% of the plants are killed (LI50) was lowest in the cool autumn in 1988 and highest in the warm autumn in 1989. Temperatures below 5 °C were also required for expression of resistance. Differences in LI50 between resistant and susceptible cultivars were most apparent in late autumn. Continuous snow cover was found to reduce resistance to pink snow mold. The rate of decline of the resistance in cv. Nanbukomugi during the winters under snow was lower than in cv. PI 173438 and cv. Kitakamikomugi. The resistance to pink snow mold was correlated with the amount of etiolated growth at 25 °C. This indicates that exhaustion of food reserves during prolonged snow cover predisposed wheat plants to snow mold diseases. Key words: pink snow mold, Fusarium nivale, Monographella nivalis, resistance progressive and degressive curves, Triticum aestivum L., field test.