engleski

Diallel Analysis of Maize Resistance to Anthracnose Stalk Rot

Anthracnose stalk rot (ASR) caused by Colletotrichum graminicola (Ces.) Wils. has become an important disease of maize (Zea mays L.) in Croatia. The purpose of this study was to evaluate general and specific combining effects for ASR resistance using three methods of rating. Seven maize inbreds and their 21 diallel crosses were tested for ASR resistance under artificial infection at Rugvica in 1993. Two methods of rating for ASR resistance total number of internodes infected (SR1), and number of internodes infected more than 75 % (SR2) were highly correlated (r=0.98**), but the third method of rating outer stalk discoloration (SR3) was in a low correlation with other two methods. Line resistance per se corresponded with resistance in hybrid combinations, which support the process of breeding for resistance line development. Sources of resistance Bc10 and LB31 expressed significant negative GCA effects for SR1 and SR2, as well as inbred lines H99 and Mo17, which means that they incorporate resistance into hybrid combinations. Lines Bc14 and B73 were susceptible to ASR with considerable positive GCA effects for SR1 and SR2. Two sources of resistance, ZP4 and Bc10, displayed significant negative GCA effects for SR3, while a third source LB31 and line Bc14 were susceptible with significant positive GCA effects. Significant SCA negative effects were obtained for certain hybrid combinations involving domestic inbred line Bc10 which exhibited higher resistance in comparison with the known source LB31 and it is recommended as a source of resistance to ASR.

maize; anthracnose-stalk rot; diallel analysis; sources of resistance

nije evidentirano