Changes in nitrogen content in malformed inflorescence of mango caused by Fusarium moniliforme Sheld. var. subglutinans Wr. et Rg.

Abstract

Fusarium moniliforme Sheld. var. subglutinans Wr. et Rg. causes malformations in young inflorescences of mango and seriously affects fruit formation. Quantitative studies of total, soluble and protein nitrogen contents of malformed inflorescence of two cultivars, ‘Himsagar’ and ‘Bombai’ were made. Healthy inflorescences of the former cultivar showed slightly higher nitrogen content than that of the latter. After infection, considerable increases in both soluble and protein fractions of nitrogen were observed in both host varieties. The proportion of these two nitrogen fractions, however, showed some changes in ‘Bombai’ but in ‘Himsagar’ it remained more or less unaltered.     

Isolation of beauvericin as an insect toxin from Fusarium semitectum and Fusarium moniliforme var. subglutinans

Nonpolar methylene chloride-soluble extracts from the mycelia of Fusarium semitectum and Fusarium moniliforme var. subglutinans were toxic to Colorado potato beetles. The major toxic metabolite was isolated and found to be the cyclodepsipeptide, beauvericin. This is the first report of the isolation of beauvericin from the genus Fusarium.     

Effect of Fusarium moniliforme var. subglutinans Infection on Mangiferin Production in the Twigs of Mangifera indica

The effect of Fusarium moniliforme var. subglutinans on the concentration of mangiferin (1,3,6,7-tetrahydroxyxanthone-C₂-beta-D-Glucoside) was studied. The role of the temperature gradient on the severity of infection and mangiferin production was examined in the light of the proliferation of the fungus. The infection prevented the transportation of mangiferin from the site of its synthesis to the storage site (bark). The variation in the concentration of mangiferin was attributed to its conversion to a polymeric quinone.     

Ice Nucleus Production of Fusarium moniliforme var. subglutinans in Relation to Its Growth Characteristics

The effects of culture conditions on the ice nucleus production of Fusarium moniliforme var. subglutinans isolated from the gut of larvae of the rice stem borer (Chilo suppressalis Walker) were examined. The ice nucleus production was only affected by cultivation temperature and pH: the optimum temperature and pH were 15°C to 20°C and 4.0 to 6.0, respectively.     

Presence of a Root Malformation Factor in Culture Filtrates of Fusarium moniliforme var. subglutinans1

The presence of a root malformation factor, different from plant growth substances viz. NAA, GA₃, Kinetin and reduced Glutathion was demonstrated in culture filtrates of Fusarium moniliforme var. subglutinans, a fungus commonly associated with malformed mango tissues. Culture filtrate extracts of the fungus caused curling and stunting of maize and pea roots and formation of flap like growth at the tip of wheat roots, but failed to induce malformation in bean plants as reported, for malformin.     

Relationship of phenotypic and genetic variation in Plantago lanceolata to disease caused by Fusarium moniliforme var. subglutinans

Summary Naturally established individuals of Plantago lanceolata with the inflorescence disease caused by Fusarium moniliforme var. subglutinans had more inflorescences and were more likely to be male-sterile than healthy plants. Half-sib families planted in the field varied in the percentage of diseased plants, the number of inflorescences per plant, the incidence of male-sterility, and the pattern of inflorescence phenology. The rankings of families with respect to disease incidence was, however, not simply related to their reproductive phenotypes. Plants derived from field genotypes with a history of disease were slightly more likely to become diseased than plants derived from healthy genotypes. Inflorescence infection was more severe on plants derived from genotypes with a known history of disease. Since the fungus reduces seed production in the plants it infects, differential incidence of disease based on plant phenotype and genotype may have ecological and evolutionary consequences for the host population.     

Spatial patterns of disease induced by Fusarium moniliforme var. subglutinans in a population of Plantago lanceolata

Summary At low densities, Plantago lanceolata was less likely to have the inflorescence disease caused by the fungus Fusarium moniliforme var. subglutinans. Where the disease was found, as host density increased, the proportion diseased remained constant or decreased. The pathogen's inability to exploit high host densities may be due to both the long disease cycle and the reduced efficiency of disease spread in heterogeneous habitats. Diseased plants were randomly spaced early in the summer but were later found in clusters, probably as a result of localized spore dispersal. Spatial patterns of disease levels remained constant from year to year.     

The Disease Cycle of Mango Malformation Induced by Fusarium moniliforme var. subglutinans and the Curative Effects of Mangiferin-Metal Chelates

Evidence is presented to suggest that the bunchy top, die-back, abnormal inflorescence and blossom blight disease of Mangifera indica are interlinked and can be expressed as a disease cycle in mango malformation. The morphological and biochemical connections among these symptoms, induced by Fusarium moniliforme var. subglutinans Wollenw. and Reink., are appraised. Partial control of the mango malformation has been accomplished by spraying the diseased parts with mangiferin-Zn²⁺ and mangiferin-Cu2+ chelates. The salutory effect of niangiferin-metal chelates is evidenced by the revival of normal balance of mangiferin and the micronutrients in the diseased parts, dechne in the fungal population and emergence of healthy shoots.     

Biotic relation between Fusarium oxysporum schlecht. and fungi isolated from the substrate of Stewartia pseudocamellia (max.)

The effect of the fungi community colonizing the substrate of Stewartia plants on the growth of Fusarium oxysporum Schlecht. was investigated. The soil samples from 2 years old Stewartia cuttings were taken for analysis in the second decade of October 2002 and 2003, when the symptoms of disease appeared on Stewartia plant. Fungi were isolated from the substrate using the sand method (Mańka K. 1974). Fusarium oxysporum were isolated from root system of Stewartia pseudocamellia plant. The isolates selected for the investigation proved pathogenic influence on Stewartia in an infection experiment. For estimation of biotic effect of saprobiotic fungi community on Stewartia pathogen F. oxysporum the biotic series method (Mańka K. 1974) was applied. The results showed that species of genera: Penicillium and Trichoderma were the most frequent in the community of fungi in the substrate. Both fungi communities of these fungi could not limit the growth of investigated pathogen F. oxysporum. It showed negative ABSTRACT biotic effect. The strongest antagonistic effect displayed Trichoderma viride and Trichoderma harzianum.     

Comparison of Fusarium oxysporum and Fusarium oxysporum var. redolens by Analyzing the Isozyme and Serological Patterns

Extracts from Fusarium oxysporum (F.o.) and F. oxysporum var. redolens (F.o.r.) isolates were compared by means of electrophoresis and crossed immunoelectrophoresis. The polymorphism of five isozyme systems allowed a distinction between F.o. and F.o.r. isolates. The isozyme patterns of three other isozyme systems did not allow this distinction between F.o. and F.o.r. to be made. Both fungi appeared almost identical serologically. Relative amounts of their corresponding proteins differed but the qualitative patterns of the proteins were nearly the same with the anti-F.o.r. serum, only one specific antigen was detected in the extracts from F.o.r., isolates. Although the results obtained indicate a strong similarity between F.o. and F.o.r., they are not sufficient for an unequivocal statement that the fungi belong to the same species.     

Response of corn plants to the effect of salicylic acid and Fusarium moniliforme

Effect of salicylic acid and Fusarium moniliforme on trypsin inhibitor activity, lectine activity, lectine carbohydrate specificity, and salicylic acid content in sprouted maize was studied. Changes in trypsin inhibitor activity, lectine activity, and content of endogenous salicylic acid during action of exogenous salicylic acid or pathogen were shown to depend on resistance of maize lines to fusariosis pathogen. Salicylic acid was proposed to take part in induction of trypsin and lectine inhibitors. Trypsin and lectine inhibitors are important in formation of sprouted maize resistance to abiotic and biotic factors.