Kasoma Chapwa, Shimelis Hussein, Laing Mark D, Mekonnen Bethelihem
African Centre for Crop Improvement, University of KwaZulu-Natal, Private Bag X01, Scottsville, Pietermaritzburg 3209, South Africa.
Centre for Agriculture and Bioscience International (CAB International) Southern Africa Centre, 5834 Mwange Close, Kalundu, Lusaka P.O. Box 37589, Zambia.
Insects. 2022 Nov 4;13(11):1020. doi: 10.3390/insects13111020.
Knowledge of fall armyworm (FAW) (Spodoptera frugiperda J.E. Smith) rearing, infestation and development and precision screening protocols are preconditions for the successful introgression of resistance genes into farmer-preferred varieties. We aimed to determine FAW developmental stages, screen tropical maize and select resistant lines under controlled conditions in Zambia. Field-collected FAW samples constituting 30 egg masses and 60 larvae were reared using maize leaf- and stalk-based and soy- and wheat flour-based diets at 27 ± 1 °C, 60 ± 5% relative humidity and 12 h day length. The resulting neonates were separated into sets A and B. The life cycles of set A and field-collected larvae were monitored to document the FAW developmental features. Set B neonates were used to infest the seedlings of 63 diverse tropical maize genotypes. Egg, larva, pupa and adult stages had mean durations of 2, 24, 20 and 12 days, respectively. Test maize genotypes revealed significant differences (p < 0.05) based on FAW reaction types, with lines TL13159, TL02562, TL142151, VL050120 and CML548-B exhibiting resistance reactions, while CML545-B, CZL1310c, CZL16095, EBL169550, ZM4236 and Pool 16 displayed moderate resistance. These genotypes are candidate sources of FAW resistance for further breeding. This study will facilitate controlled FAW rearing for host screening in the integration of FAW resistance into market-preferred maize lines.
了解草地贪夜蛾（FAW）（草地贪夜蛾，J.E. 史密斯）的饲养、侵染和发育情况以及精准筛选方案，是将抗性基因成功导入农民喜爱品种的前提条件。我们旨在确定赞比亚可控条件下草地贪夜蛾的发育阶段、筛选热带玉米并选择抗性品系。使用以玉米叶和茎为基础以及以大豆和小麦粉为基础的饲料，在27 ± 1 °C、相对湿度60 ± 5%和12小时日照长度的条件下，饲养从田间采集的30个卵块和60只幼虫组成的草地贪夜蛾样本。将孵化出的幼虫分为A组和B组。监测A组幼虫和田间采集幼虫的生命周期，以记录草地贪夜蛾的发育特征。B组幼虫用于侵染63种不同热带玉米基因型的幼苗。卵、幼虫、蛹和成虫阶段的平均持续时间分别为2天、24天、20天和12天。基于草地贪夜蛾的反应类型，测试的玉米基因型显示出显著差异（p < 0.05），其中TL13159、TL02562、TL142151、VL050120和CML548 - B品系表现出抗性反应，而CML545 - B、CZL1310c、CZL16095、EBL169550、ZM4236和Pool 16表现出中度抗性。这些基因型是进一步育种中草地贪夜蛾抗性的候选来源。本研究将有助于在将草地贪夜蛾抗性整合到市场青睐的玉米品系过程中，进行可控的草地贪夜蛾饲养以用于寄主筛选。
