| Heritability and Genetic Advance Narrow-sense heritability estimates for different traits are given in Table (3). The values were very high for plant height, moderate for date headed and number of spikelets per spike and low for the remaining traits. Small narrow sense heritabilities for most traits may be due to the dominance and epistatic effects on these traits. The negative estimate of heritability observed for 100-kernel weight may be attributed to several causes, such as sampling error, differential responses of the F2 vs. the backcrosses to environment and nonadditive genetic effects. Estimates of the expected genetic advance (G.S.) are reported in Table (3). The results showed that heritability and genetic advance generally agreed in showing those traits for which selection in the F2 would lead to substantial improvement. The highest estimates of heritability and genetic advance were presented for plant height, date headed and spikelets per spike indicating that selection for these traits would be effective in this material, Contradictory the low heritability estimates for the major traits should result in a low genetic advance. Similar results were obtained by BHATT (1972) and ABO-ELENIN and GOMMA (1977) for plant height, and ALI and EL-HADDAD (1978) for harvest index. Regarding earliness, hight and kernels per spike FONSECA and PATTERSON (1968), and KETATA et al, (1976) gave similar findings. The low heritability obtained for grain yield are in agreement with that reported by JOHNSON et al. (1966). Literature cited ABO-ELENEIN, R.A. and A.A. GOMMA, 1977. Egypt. J. Genet. Cytol. 6: 52-61. ALL, M.I. and M.M. EL-HADDAD, 1978. Egypt. J. Genet. Cytol. 7: 251-265. ALLARD, R.W., 1960. John Wiley and Sons, Inc., New York. AMAYA, A.A., R.H. BUSCH, and K.L. LEBSOCK, 1972. Crop Sdi. 12: 478-481. BHATT, G.M., 1972. Crop Sci. 12: 95-98. CHAPMAN, S.R. and F.H. MCNEAL, 1971. Crop Sci. 11: 384-386. FONSECA, S., and PATTERSON, 1968. Crop Sci. 8: 614-617. GAMBLE, E.E., 1962. Can. J. Plant Sci. 42: 339-348. HALLORAN, G.M., 1975. Z. Paflanzenziichtg. 74: 18-27. HASSANIEN, E.H., A.K.A. SELIM, H.A. IBRAHIM and S.E.A. ATTIA, 1974. Agric. Res. Review. 52: 1- 11. HAYAMAN, B.I., 1958. Heredity. 12: 371-390. JOHNSON, V.A., K.J. BIEVER, A. HAUNOLD and J.W. SCHMIDT, 1966. Crop Sci. 6: 336-338. KETATA, H., L.H. EDWARDS, and E.L. SMITH, 1976. Crop Sci. 16: 19-22. MATHER, K., 1949. Biometrical genetics. Dover Publications, Inc., London. MATHER, K., and J.L. JINKS., 1971. Biometrical genetics. Cornell University Press, Ithaca. New York. MATZINGER, D.F., T.J. MANN, and H.F. ROBINSON, 1960. Agron. J. 52: 8-11. SUN, P.L.F, H.L. SHANDS and R.A. FORSBERG, 1972. Crop Sci. 12: 1-5. WARNER, J.N., 1952. Agron. J. 44: 427-430. WIDNER, J.N. and K.L. LEBSOCK, 1973. Crop Sci. 13: 164-167. |
| <-- Back |