Susceptible Maize Genotypes Research Articles

Resistance in Susceptible Maize toHelminthosporium carbonumRace 1 Induced by Prior Inoculation with Race 2

Inoculation of leaves of susceptible maize genotypes with the nonpathogenic race 2 of Helminghosporium carbonum at least 10 hr before inoculation with the pathogenic race 1 prevented development of large lesions typical of the susceptible reaction. Appressorium formation, penetration, and hyphal growth by the pathogen were decreased. Addition of HC-toxin (the host-specific toxin produced by pathogenic race 1) to the race 1 challenge inoculum abolished the resistance induced by race 2 (...)

Ovipositional responses of Chilo partellus (Swinhoe) to certain susceptible and resistant maize genotypes

The ovipositional responses of the stem-borer, Chilo partellus, to the susceptible maize genotype, inbred A, are higher than to the resistant genotype, ICZ1-CM. These responses are elicited by certain characters of the plants that are perceivable prior to the moths’ arrival on the plants (distance-perceivable) as well as those perceivable after arrival on the plant (contact-perceivable). Distance-perceivable characters were not found to be responsible for the differences in the oviposition on the two genotypes tested.

Development of a Third Backup System for European Corn Borer (Lepidoptera: Pyralidae) Egg Production

Occasionally, fall field populations of European corn borers (ECB), Ostrinia Nubilalis Hubner, are so small that it is difficult to collect sufficient numbers of larvae to start a new culture. Our data show that diapausing larvae can be collected from a second-generation ECB maize, Zea mays L., nursery for at least 5 years consecutively without loss in virulence of the insect to cause extensive damage to susceptible genotypes of maize.

Maize sterile stunt — a delphacid transmitted rhabdovirus disease affecting some maize genotypes in Australia

A rhabdovirus disease causes severe stunting and sterility of a few susceptible maize (Zea mays L.) genotypes in eastern Australia. Maize sterile stunt virus (MSSV) also infected Aegilops variabilis Eig, barley (Hordeum vulgare L.), barnyard grass (Echinochloa colona (L.) Link.), triticale (x Triticosecale Wittmack), wheat (Triticum aestivum L.), T, aethiopicum Jakubz., T, monococcum L, and T. turgidum L. MSSV was transmitted with low efficiency by the maize planthopper Peregrinus maidis (Ashm.) and by Sogatella kolophon (Kirk.), but the chief natural vector was Sogatella longifurcifera Esaki and Ishihara, a delphacid found commonly on affected maize and on E. colona. The incubation period of MSSV in P, maidis was 10-14 days after acquisition on infected plants or 9-12 days after injection of infective sap. Transmission was demonstrated during a period of up to 23 days or until the insects died. Field incidence in the maize lines B37 and H84 often exceeded 90 %, but most maize lines were resistant and resistance was highly dominant. Temperate cereals were severely affected only during summer and triticale was the most susceptible. Particle dimensions were 230 by 50 nm in negative stain and 255 by 45 nm in thin section, with accumulations of particles found only in cytoplasmic vesicles. MSSV particles occurred mainly in companion cells, phloem parenchyma and bundle sheath cells in maize. Virus-like particles were also found in the brain and salivary glands of infective P. maidis.