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Fifty well established, morphologically uniform and advanced inbreds of maize (Zea mays L.) were screened against stem borer (C. partellus) under artificial infestation conditions. Their average leaf injury rating varied, on 0-10 scale, varied from 3.8 to 8.4 thus none of the studied genotypes was found to be immune to the pest infestation. Out of the screened maize genotypes six highly resistant (335, 551-1, 645-3, 1324-A, 586-3 and 766(O)) and six susceptible (423, 1040-5, 323-8, 295, 877, 1015 (2+13)) genotypes were used for developing 35 F1 crosses. Responses of F1 crosses to stem borer under artificial infestation conditions revealed that the crosses between resistant genotypes were resistant to stem borer infestation, while those between resistant × susceptible and susceptible × resistant were towards resistant side. However, the susceptible × susceptible crosses were susceptible to stem borer infestation. This indicated that resistance to stem borer in maize is dominant over susceptibility. The identified inbred lines variously resistant to C. partellus may be used as parents in hybrid breeding programmes that emphasize stem borer resistance or as sources of resistance in breeding programs.
Keywords: Maize genotypes, C. partellus, Infestation, Susceptible.