Components of Quantitative Resistance to Philippine Downy Mildew In Maize

Abstract

Resistance to Philippine downy mildew (Peronosclerospora philippinensis) was observed in a BC1F2 population developed from a cross between the susceptible inbred line Pi 23 and the resistant inbred line P 345. Five components of resistance namely, disease incidence, disease severity, onset of systemic symptoms, the-area- underdisease-progress- curve (AUDPC), and rate of downy mildew development affected host resistance reactions. All components were significantly correlated. The adult plant resistant reaction was evident in resistant progenies showing prolonged onset of systemic symptoms. Transgressive segregation that exceeded the high and low parent values was also observed for all components of quantitative resistance to Philippine downy mildew.

Breeding for Prolificacy, Total Carotenoids and Resistance to Downy Mildew in Small-Ear Waxy Corn by Modified Mass Selection

“…Thus, DSI was indirectly associated with AUDPC-DSI and AUDPC-DI, and evaluation of any disease parameter was sufficient to identify disease resistance. Similar results were reported in field corn [60]. Moreover, close and positive relationships among these parameters were also reported in wheat [61] and chickpea [62].…”