عنوان

Genetic and mycotoxin studies of Fusarium nygamai, and the effect of calcium nutrition on Fusarium seedling blight of maize

Number

TLpq304208421

.Language of Text, Soundtrack etc

انگلیسی

Title Proper

Genetic and mycotoxin studies of Fusarium nygamai, and the effect of calcium nutrition on Fusarium seedling blight of maize

General Material Designation

[Thesis]

First Statement of Responsibility

J. A. Klaasen

Subsequent Statement of Responsibility

P. E. Nelson

Name of Publisher, Distributor, etc.

The Pennsylvania State University

Date of Publication, Distribution, etc.

1995

Specific Material Designation and Extent of Item

115

Dissertation or thesis details and type of degree

Ph.D.

Body granting the degree

The Pennsylvania State University

Text preceding or following the note

1995

Text of Note

Two Fusarium species, F. moniliforme and F. nygamai associated with maize, millet and sorghum grain and soil may be misidentified based on morphological characteristics. Isolates of F. nygamai were mated and produced fertile perithecia on carrot agar. The new mating population has a Gibberella teleomorph. Female-fertile tester strains were recovered from the random ascospore progeny and two were identified as more reliable female parents in the detection of other members of this population. Anamorph characteristics of progeny cultures indicates that the formation of microconidia in short chains and the formation of chlamydospores are suitable characteristics for species identification of F. nygamai. Fusarium isolates from millet and sorghum grain, and soil in Nigeria, Lesotho and Zimbabwe were initially identified as short- and long-chained types of F. nygamai. Some of the strains with longer chains of microconidia which did not produce chlamydospores, but swollen hyphal cells of resistant hyphae were crossed with the mating populations "A" and "F" of F. moniliforme in section Liseola. Of the long chains of microconidia and other characteristics of F. moniliforme, 64% crossed with mating population "A". Of the isolates with short chains of microconidia and chlamydospores, characteristic of F. nygamai, 65% crossed with the testers used to produce the teleomorph of F. nygamai. Fusarium nygamai strains were mated on carrot agar to study the heritability of mating type and fumonisin production in ascospore progeny. Progeny from four crosses segregated in 1:1 ratios for loci controlling mating type. A single genetic locus controls fumonisin B (FB) production as well as higher FB and FB2 production. A quantitative trait locus for FB and FB2 production was also found through correlated responses of progeny. The role of calcium in plant growth was investigated in relation to a defense response against seedling blight of maize induced by F. moniliforme. Optimal shoot length and shoot dry weight and reduced root length were obtained with 10 and 20 mM CaCl2. The results of this study demonstrate that calcium plays a role in defense against Fusarium seedling blight and that this can be mainly attributed to its role in cell membrane and cell wall stability.

Biological sciences

Genetics

Plant pathology

J. A. Klaasen

P. E. Nelson

Electronic name

p

[Thesis]

276903

a

Y