Host resistance and pathogen conidial characteristics across locations of Philippine corn downy mildew

Issue Date

12-2005

Abstract

The performance of 28 maize inbred lines from the Centre Internacional de Mejoramiento de Maiz y Trigo (CIMMYT) and the Institute of Plant Breeding (IPB) of the University of the Philippines Los Banos was assessed for resistance to the downy mildew pathogen, Peronosclerospora philippinensis (Weston) Shaw, at different geographic locations. Epidemiological parameters of resistance were also investigated. Two inbreds, i. e. Nei 9008 and P345C4S2B46-2-2-1-2-B-B-B, exhibited a high degree of resistance in the experimental farm of the University of the Philippines Los Baños (UPLB) and in Koronadal, Cotabato. Some resistant lines in UPLB became less resistant in Koronadal. For the components of resistance that were investigated, significant differences were observed among the entries. The percentage of the incidence of disease was lower in the resistant lines; area under disease progress curve (AUDPC) values and the rate of disease incidence were also lower. Differences in conidial size and shape among downy mildew pathogen populations in the different locations using susceptible trap lines were detected. The results suggested that location and genotype affected conidial size and shape. Higher spore germination in Koronadal than in UPLB could be due to more favorable environmental conditions for germination, i.e., heavier dew formation during the early morning in Koronadal.

Source or Periodical Title

Philippine Agricultural Scientist

ISSN

317454

Volume

88

Issue

4

Page

489-494

Document Type

Article

Language

English

Subject

Maize, Philippine downy mildew, Resistance

Digital Copy

none

This document is currently not available here.

Share

COinS