棉铃虫为害与拟轮生镰孢侵染对玉米穗腐病发生及玉米籽粒中伏马毒素污染水平的影响

本研究以‘浚单20’为供试玉米品种,以棉铃虫为供试昆虫,以拟轮生镰孢为供试病原菌,分别进行单独及复合处理,以明确棉铃虫和拟轮生镰孢单独处理和复合处理对玉米穗腐病发病程度及籽粒中伏马毒素污染水平的影响。结果表明,2011年和2012年均以棉铃虫与拟轮生镰孢侵染复合处理对穗腐病发病程度及籽粒中伏马毒素污染水平的影响最大,穗腐病平均病级分别为0.68±0.05和1.08±0.19;单独接种棉铃虫,2011年和2012年的穗腐病平均病级分别为0.31±0.05和0.71±0.06;单独接种拟轮生镰孢,穗腐病平均病级分别为0.24±0.03和1.05±0.29。复合处理的籽粒中伏马毒素污染水平,2011年和2012年分别为(0.85±0.56)mg/kg和(2.36±0.98)mg/kg;单独接种棉铃虫处理分别为(0.17±0.12)mg/kg和(0.01±0.002)mg/kg;单独接种拟轮生镰孢处理分别为(0.10±0.03)mg/kg和(1.14±0.62)mg/kg。相同处理条件下,降水量大和相对湿度高的气候条件更有利于穗腐病的发生及籽粒中伏马毒素的积累。

Effects of infestation by Helicoverpa armigera together with Fusarium verticillioides on the severity of maize ear rot and the contamination level of fumonisin in kernels

The morphology and distribution of the larval head sensilla of Sphecodoptera sheni (Arita & Xu) were studied by using scanning electron microscopy. The results showed that the head structure type of the larvae was hypognathous. The head contained antennae, ocellus, labrum, labium, mandible, maxilla, spinneret and so on. Three kinds of sensilla were found on antennae of the larvae: the basal scape is devoid of sensilla, and the pedicel possesses three sensilla chaetica and two sensilla basiconica. The terminal flagellum carried one sensillum styloconicum and one sensilla basiconica distally. Seven types of sensilla were found on the mouthparts: sensilla chaetica were widespread and abundant; sensilla basiconica and B?hm bristles were mainly located on the maxillary palp and galeae; sensillum styloconicum were found on the galeae and labial palp; sensilla basiconic mastoid were located on the galeae; sensilla squamiformia were found on the lateral margin of the basal segments of labial palp, and sensilla furcatea were only present on the labrum.