Screening and selection of tropical maize genotypes for drought tolerance using primary and secondary traits
1999
Manda, T.H.E. | Mwambula, C. (Mount Makulu Research Station, Chilanga (Zambia). Maize Breeders)
Elite tropical maize germplasm contains considerable genetic variability for yield, anthesis-silking interval (ASI), and other morphological and physiological traits indicative of improved performance under drought. Eighty-one top crosses, five populations and ten hybrids were evaluated for drought tolerance both under natural rainfall conditions in the 1996/97 main season and under managed drought stress conditions in the 1997 winter dry season. Evaluation under managed drought stress was conducted at the National irrigation Research Station (NIRS) in southern Zambia and water was withheld for five weeks before and during flowering. Genotypes yielded between 2.4 tonnes ha-1 and 4.6 tonnes ha-1 under natural rainfall conditions and between 0.5 tonnes ha-1 and 5.7 tonnes ha-1 under managed drought conditions. Anthesis-silking interval and number of ears per plant were the only secondary traits that significantly (P0.05) correlated with grain yield at both sites. We conclude that ASI can provide information at flowering to direct crosses for a drought breeding program as it gives a reasonable estimate of yield well before harvest.
显示更多 [+] 显示较少 [-]