RESISTANCE TO LEAF-FEEDING BY THE FALL ARMYWORM (LEPIDOPTERA, NOCTUIDAE) IN TISSUE-CULTURE DERIVED SORGHUMS

Sorghum (Sorghum bicolor (L.) Moench) genotypes regenerated from tissue culture were evaluated under field and laboratory conditions for resistance to leaf-feeding by the fall armyworm, Spodoptera frugiperda (J. E. Smith). Two regenerated lines were identified as having a significantly higher level of resistance to fall armyworm feeding as compared with the non-regenerated and susceptible parent, 'Hegari.' Laboratory studies measuring growth and development of fall armyworm were conducted with meridic diets containing dried sorghum foliage from regenerated or non-regenerated plant material. Significant reductions in larval weights were detected for two R3 lines compared with the non-regenerated parent, suggesting that antibiosis may be involved. Free-choice studies revealed a significant degree of non-preference for the R3 line that had shown the greatest adverse effect on fall armyworm growth in the developmental studies. These results indicate that tissue culture-induced variations can be a viable means of generating new sources of genetic diversity for use in crop improvement.