Genetic resistance to pearl millet downy mildew III: Resistance in photoperiod sensitive accessions

Genetic resistance is the most economic and feasible method of control of downy mildew (DM; Sclerospora graminicola) of pearl millet (Pennisetum glaucum). In this study, a systematic search for downy mildew resistance in photoperiod-sensitive pearl millet was identified. With the availability of photoperiod-insensitive line, ICML 22, such material can be converted into day neutral background. To identify genes for DM resistance with diverse origin, we tested 1030 photoperiod-sensitive accessions from 25 countries in the greenhouse and in field disease nurseries during the summer and rainy seasons of 1993 at Patancheru, Andhra Pradesh, India. A total of 50 accessions remained DM-free and 300 accessions were within 1-5% DM reaction category against the Patancheru pathotype in a preliminary screening under greenhouse conditions. Of the 50 accessions tested, 17 accessions remained completely free from DM infection against Patancheru and Mysore pathotypes both under greenhouse and field conditions. However, only 11 accessions revealed potential resistance against Patancheru and Mysore pathotypes when tested using the most severe inoculation methods (inject, drop and dip) under greenhouse conditions at Patancheru