Bhadmus Olatunde A, Badu-Apraku Baffour, Adeyemo Oyenike A, Ogunkanmi Adebayo L
Department of Cell Biology and Genetics, University of Lagos, Lagos 101017, Nigeria.
International Institute of Tropical Agriculture, IITA, PMB 5320 Oyo Road, Ibadan 200001, Nigeria.
Plants (Basel). 2021 Nov 26;10(12):2596. doi: 10.3390/plants10122596.
An increase in the average global temperature and drought is anticipated in sub-Saharan Africa (SSA) as a result of climate change. Therefore, early white quality protein maize (QPM) hybrids with tolerance to combined drought and heat stress (CDHS) as well as low soil nitrogen (low-nitrogen) have the potential to mitigate the adverse effects of climate change. Ninety-six early QPM hybrids and four checks were evaluated in Nigeria for two years under CDHS, low-nitrogen, and in optimal environments. The objectives of this study were to determine the gene action conditioning grain yield, assess the performance of the early QPM inbred lines and identify high yielding and stable QPM hybrids under CDHS, low-nitrogen and optimal environment conditions. There was preponderance of the non-additive gene action over the additive in the inheritance of grain yield under CDHS environment conditions, while additive gene action was more important for grain yield in a low-nitrogen environment. TZEQI 6 was confirmed as an inbred tester under low N while TZEQI 113 × TZEQI 6 was identified as a single-cross tester under low-nitrogen environments. Plant and ear aspects were the primary contributors to grain yield under CDHS and low-nitrogen environments. TZEQI 6 × TZEQI 228 and the check TZEQI 39 × TZEQI 44 were the highest yielding under each stress environment and across environments. Hybrid TZEQI 210 × TZEQI 188 was the most stable across environments and should be tested on-farm and commercialized in SSA.
由于气候变化，预计撒哈拉以南非洲地区（SSA）的全球平均气温将上升且干旱情况会加剧。因此，对干旱和热胁迫（CDHS）以及低土壤氮含量（低氮）具有耐受性的早熟优质蛋白玉米（QPM）杂交种有潜力减轻气候变化的不利影响。在尼日利亚，对96个早熟QPM杂交种和4个对照品种在CDHS、低氮和最佳环境条件下进行了两年的评估。本研究的目的是确定影响籽粒产量的基因作用，评估早熟QPM自交系的表现，并在CDHS、低氮和最佳环境条件下鉴定高产且稳定的QPM杂交种。在CDHS环境条件下，籽粒产量的遗传中，非加性基因作用比加性基因作用占优势，而在低氮环境中，加性基因作用对籽粒产量更为重要。TZEQI 6被确认为低氮条件下的自交测验种，而TZEQI 113×TZEQI 6被鉴定为低氮环境下的单交测验种。在CDHS和低氮环境下，植株和穗部性状是籽粒产量的主要贡献因素。TZEQI 6×TZEQI 228和对照品种TZEQI 39×TZEQI 44在每种胁迫环境及所有环境下产量最高。杂交种TZEQI 210×TZEQI 188在所有环境中最为稳定，应在SSA进行农场试验和商业化种植。
