Aluminium toxicity in acidic soils (Al) and the maize streak virus disease (MSV) cause significant losses in maize productivity. These constraints can occur simultaneously in sub-Saharan Africa but there are no maize hybrids that combine resistance for both stresses. Therefore, the objectives of the study were to determine combining ability, gene action and heterosis for MSV and Al tolerance in maize. Ninety-nine experimental hybrids were generated from a 10 × 10 factorial mating design. The experimental maize hybrids, and 21 commercial hybrids were evaluated for MSV resistance under artificial infestation in Zimbabwe, and for grain yield and agronomic performance across eight environments in South Africa and Zimbabwe. Ninety-seven experimental hybrids and five standard control hybrids were evaluated for Al tolerance in a laboratory in South Africa. There were significant (p < 0.05) differences among hybrids for agronomic traits, grain yield, and MSV and Al toxicity tolerance. Only general combining ability effects were significant (p < 0.05) for grain yield and grain moisture content, while specific combining ability effects were significant (p < 0.05) for number of ears and ear prolificacy. Both GCA and SCA effects were significant for the Al toxicity tolerance related traits, indicating that Al tolerance was governed by both additive and non-additive gene action. Although hybrids displayed highly significant variation for MSV resistance, the GCA and SCA mean squares were not significant and only accounted for 59% of the hybrid sum of squares, suggesting that MSV resistance was partly under qualitative inheritance. The F1 hybrids displayed MSV severity scores similar to those of their MSV resistant parents, suggesting that probably simple dominance gene effects were involved. The hybrids also displayed significantly high levels of heterosis for both Al and MSV resistance, indicating that hybridisation would be effective in generating improved varieties. At least 60% of the hybrids were resistant to Al toxicity and more than 87% were MSV resistant, indicating that there is potential to develop varieties with resistance to both stresses.

酸性土壤（Al）中的铝毒害和玉米条纹病毒病（MSV）导致玉米生产力的重大损失。这些限制可能在撒哈拉以南非洲同时发生，但没有将两种抗性结合在一起的玉米杂交种。因此，本研究的目的是确定玉米MSV和Al耐性的组合能力，基因作用和杂种优势。从10×10因子交配设计中产生了99个实验杂种。在津巴布韦，对玉米杂交种和21种商品化杂种进行了人工侵染后的MSV抗性评估，并在南非和津巴布韦的八个环境中评估了谷物产量和农艺性能。在南非的一个实验室中评估了97个实验杂种和5个标准对照杂种的耐铝性。有重大（p  <0.05）杂交种在农艺性状，籽粒产量以及MSV和Al毒性耐受性方面的差异。 对于谷物产量和谷物含水量，只有一般的结合能力影响显着（p <0.05），而特定的结合能力影响则显着（p <0.05）的耳朵数和耳朵丰满度。GCA和SCA的影响对于铝毒性耐受相关性状均很重要，表明铝耐受性受加性和非加性基因作用的支配。尽管杂种表现出极高的MSV抗性变异，但GCA和SCA均方并不显着，仅占杂种平方和的59％，这表明MSV抗性部分属于定性遗传。F1杂种表现出的MSV严重性得分与其耐MSV的父母相似，表明可能涉及简单的优势基因效应。杂种还显示出高水平的Al和MSV抗性杂种优势，表明杂交将有效地产生改良的品种。