Abstract

                                Sorghum downy mildew (SDM) of maize caused by Peronosclerospora sorghi is a disease of great destructive potential because systemically infected plants seldom produce an ear. Breeding resistant varieties is one of the most effective and cheap methods to control this disease. The genetics of resistance is needed to be studied in any resistance breeding programme. In the present investigation, the inheritance study revealed that resistance was governed by two recessive genes in complementary (9:7) pattern in F2 population of a cross, UMI 79 x UMI 936(w). The resistance behaved as a recessive character to susceptibility. Four SRR primers namely bnlg1035, bnlg420, Phi073 and bnlg1154 were found to be polymorphic between resistant and susceptible parents and they can be further effectively utilized in molecular mapping for SDM resistance. Sorghum downy mildew (SDM) of maize caused by Peronosclerospora sorghi is a disease of great destructive potential because systemically infected plants seldom produce an ear. Breeding resistant varieties is one of the most effective and cheap methods to control this disease. The genetics of resistance is needed to be studied in any resistance breeding programme. In the present investigation, the inheritance study revealed that resistance was governed by two recessive genes in complementary (9:7) pattern in F2 population of a cross, UMI 79 x UMI 936(w). The resistance behaved as a recessive character to susceptibility. Four SRR primers namely bnlg1035, bnlg420, Phi073 and bnlg1154 were found to be polymorphic between resistant and susceptible parents and they can be further effectively utilized in molecular mapping for SDM resistance.

Key words : Maize, Sorghum Downy Mildew, Resistance, Genetics, Molecular markers