鲜食玉米品种心叶期对草地贪夜蛾抗性评价及不同品种受害后的产量损失

为初步探究鲜食玉米对草地贪夜蛾 Spodoptera frugiperda的抗性水平, 在田间草地贪夜蛾自然发生条件下对28个不同类型(甜玉米10个、甜糯玉米8个、糯玉米10个)的鲜食玉米品种进行了心叶期抗虫性鉴定, 研究了不同抗性水平及不同类型鲜食玉米的产量损失; 在室内研究了取食不同品种玉米苗对草地贪夜蛾幼虫发育历期的影响。经鉴定, 28个品种中无高抗及抗虫品种, 中抗品种12个, 感虫品种15个, 高感品种1个, 分别占鉴定资源总数的42.86%、53.57%和3.57%。28个品种的产量损失为8.30%~40.93%, 室内喂饲后幼虫的发育历期为11.29～15.31 d。不同类型鲜食玉米的叶部受害级别、产量损失和草地贪夜蛾幼虫发育历期无显著差异。甜玉米、糯玉米的叶部受害级别与产量损失呈正相关, 相关系数分别为0.61和0.79, 甜糯玉米的叶部受害级别与产量损失不相关。

Resistance of fresh corn varieties at whorl stage to Spodoptera frugiperda and yield loss of different infested varieties

To explore the resistance level of fresh corn varieties to Spodoptera frugiperda, resistance of twenty eight fresh corn varieties (ten sweet corn, eight sweet-waxy corn, and ten waxy corn) at whorl stage to S. frugiperda were identified under natural field conditions. Yield loss of fresh corn varieties with different resistance level and different types was assessed, and influence of corn seedlings of different varieties on larval developmental duration was investigated through an indoor feeding experiment. The results showed that there was no highly resistant or resistant variety among the 28 fresh corn varieties, 12 varieties displayed moderate resistance, 15 were susceptible and one was highly susceptible, accounting for 42.86%, 53.57%, and 3.57% of the total, respectively. The yield loss was assessed as 8.30%-40.93% in 28 varieties, and larvae feeding under laboratory conditions showed that the larval developmental duration was 11.29-15.31 d. Overall, no significant difference existed in leaf damage level, yield loss, and larvae period among the three types of fresh corn. Leaf damage level was positively related to yield loss in sweet corn and waxy corn, with a correlation coefficient of 0.61 and 0.79, respectively, while not related in sweet-waxy corn.