Bacterial leaf spot (BLS) is the most important bacterial disease in sweet pepper, causing intense defoliation under favorable conditions, leaving the exposed fruits to sunburn and decreasing the yield. To estimate genetic effects of the reaction to BLS on leaves and fruits, under the conditions of Campos dos Goytacazes (Brazil), hybrids F1, without reciprocals, were obtained from diallel crosses among five pepper genotypes, three susceptible ('UENF 1420 ', 'UENF 1421 ' and 'UENF 1422 ') and two resistant ('UENF 1381 ' and 'UENF 1382 '). Leaves were inoculated by infiltrating the mesophyll with 10³ cells/ml, adjusted with spectrophotometer. Variety and mean heterosis were significant for resistance on leaves, indicating that additive and dominant effects are involved in the genetic control of this character. For resistance in fruits, only variety effects were significant, indicating the presence of additive effects in the control of this characteristic. Based on these analyses, the genotypes 'UENF 1381 ' and 'UENF 1382 ' were selected for resistance to BLS on leaves. For resistance to BLS on fruits, 'UENF 1381' and 'UENF 1421' were the best genotypes. The best hybrids for resistance to BLS on leaves were: 'UENF 1420' x 'UENF 1421', 'UENF 1382' x 'UENF 1420', 'UENF 1381' x 'UENF 1420', 'UENF 1381' x 'UENF 1421', 'UENF 1381' x 'UENF 1422' and 'UENF 1381' x 'UENF 1382'.
Capsicum annuum L.; Xanthomonas campestris pv. vesicatoria; diallel analysis; disease resistance; heterosis; hybrids
