A field trial was conducted for 2 years in an Arredondo fine sand containing a tillage pan at 15-20 cm deep to determine the influence of subsoiling on the distribution of corn roots and plant-parasitic nematodes. Soil samples were taken at various depths and row positions at 30, 60, and 90 days after planting in field corn subsoiled under the row with two chisels and in non-subsoiled corn. At ...

The genetic transformation of certain organisms, required for gene function analysis or complementation, is often not very efficient, especially when dealing with large gene constructs or genomic fragments. We have adapted the natural DNA transfer mechanism from the soil pathogenic bacterium Agrobacterium tumefaciens, to deliver intact large DNA constructs to basidiomycete fungi of the genus Us...

The fungal genera Ustilago, Sporisorium and Macalpinomyces represent an unresolved complex. Taxa within the complex often possess characters that occur in more than one genus, creating uncertainty for species placement. Previous studies have indicated that the genera cannot be separated based on morphology alone. Here we chronologically review the history of the Ustilago-Sporisorium-Macalpinomy...

The aerial concentration of ascospores and macroconidia of Gibberella zeae (anamorph Fusarium graminearum) within small inoculated plots was measured over 2 years (1999 and 2000) in Manitoba. In July 1999, a 30 m × 30 m area was inoculated with corn kernels infested with G. zeae. Ten Rotorod spore samplers were set up in a line transect, trapping airborne ascospores of G. zeae from 1800 to 0200...

Three populations of the corn cyst nematode Heterodera zeae, one found in the rhizosphere of a fig tree and two infecting corn, were studied using the morphology and morphometry of cysts and second-stage juveniles, and compared with other populations. The intrapopulation and intraspecific variability are discussed. A simple and improved technique to prepare vulval cones for SEM is described. Th...

EGETATIVE heterozygous diploid strains of Ustilago maydis undergo sponVtaneous mitotic crossing over at low frequency, but this frequency can be increased up to 100-fold if the cells are treated with ultraviolet light (UV) (HOLLIDAY 1961b, 1962a, b, 1964). There is no indication that the induced crossing over differs in mechanism from that which has been described for spontaneous mitotic crossi...

Biological control of sugarcane smut (Ustilago scitaminea Syd.) using Trichoderma isolates is one the untapped potentials in Ethiopian plantations. To this end, study was carried ...

In this study, 10 species of Bipolaris viz.B. bicolor, B. cynodontis, B. cylindrica, B. hawaiiensis,B. prieskaensis, B. sorghicola, B. sorokiniana,B. spicifera, B. zeae and B. zeicola and four species of Curvularia viz.C. fallax, C. heteropogonicola, C. inaequalis and C. lunata were identified on graminicolous species or soil. Bipolaris cylindrica, B. prieskaensis, B. zeae,C. fallax and C. hete...

The study assessed the health quality of wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) seed samples collected from formal and informal sector in Ethiopia and Syria. In Ethiopia, several seed-borne fungi were found on wheat samples: Cochliobolus sativum, Fusarium avenaceum, F. graminearum, F. nivale, F. poae and Septoria nodorum. C. sativum was predominant with 84% of samples...

Head blight, caused by Gibberella zeae, is a significant disease among cereal crops, including wheat, barley, and rice, due to contamination of grain with mycotoxins. G. zeae is spread by ascospores forcibly discharged from sexual fruiting bodies forming on crop residues. In this study, we characterized a novel gene, ROA, which is required for normal sexual development. Deletion of ROA (Δroa) r...