[目的]揭示油茶蓝翅天牛Chreonoma atritarsis Pic.发生与寄主枝条营养物质及次生物质含量之间的相互关系,为蓝翅天牛在油茶林中的发生监测预警提供基础依据.[方法]采用五点法对蓝翅天牛在油茶幼龄林和壮龄林中的为害情况进行了调查;采用烘干称重法、蒽酮比色法、3,5-二硝基水杨酸法(DNS法)和考马斯亮蓝G-250等方法分别测定不同林龄内的油茶枝条含水量,枝条可溶性总糖、还原糖、可溶性蛋白等主要营养物质的含量,以及总酚、缩合单宁和黄酮等次生物质的含量,并进一步分析为害情况与各物质含量间的相关性.[结果]林间调查结果表明,油茶蓝翅天牛能够为害幼龄油茶林,且在幼龄林中喜为害枝高≤50 cm、直径＞1 cm枝条,尤以直径1-2 cm枝条受害最重;壮龄油茶林中在枝高＞50cm枝条、直径＞1 cm的枝条上为害较重,尤以直径＞2 cm枝条受害最重.室内研究结果揭示了油茶枝条营养物质及次生物质含量由高到低依次为可溶性总糖、还原糖、总酚、缩合单宁、可溶性蛋白和黄酮.其中,枝条韧皮部和木质部中各物质的含量存在显著差异.油茶蓝翅天牛在幼龄林内的选择为害行为和油茶枝条的还原糖与可溶性总糖之比呈显著负相关,和可溶性蛋白含量呈显著正相关;在壮龄油茶林内选择为害行为与枝条的总酚、缩合单宁含量呈显著负相关.[结论]油茶蓝翅天牛对油茶枝条的为害选择与枝条内的可溶性蛋白含量存在显著正相关关系,与还原糖与可溶性总糖含量之比、总酚含量及缩合单宁含量存在显著负相关关系.因此在林间栽培油茶植株过程中应加强对相应树龄及直径枝条植株上蓝翅天牛发生的监测预警.

为明确南方晚粳稻适宜的氮肥运筹,设计3个不同施氮水平,分别为N210(210 kg/hm2)、N255(255 kg/hm2)及N300(300 kg/hm2),基肥、分蘖肥、穗肥的施氮比例为5∶2∶3,并在N255施氮水平下设置4种不同基肥、分蘖肥、穗肥的施氮比例,分别为BR6(6∶2∶2)、BR5 (5∶2∶3)、BR4(4∶2∶4)及BR3 (3∶2∶5),研究氮肥运筹对晚粳稻产量、干物质生产及氮素利用率的影响.结果 表明,随施氮量增加,晚粳稻产量先增后降,与N255处理相比,N300及N210处理分别降低1.8％～2.0％和6.0％～7.2％.随施氮量增加,晚粳稻氮素总积累量增加,抽穗至成熟期氮素积累量及该阶段占总氮素积累量的比例、氮素偏生产力及氮素收获指数均降低.随基肥施氮比例降低,晚粳稻产量、氮素偏生产力及氮素收获指数均先增后降,镇稻11号和甬优2640分别在BR5和BR4处理时最高,但两品种在这2个处理间的差异均不显著.随基肥施氮比例降低,晚粳稻成熟期氮素积累量、抽穗期至成熟期氮素积累量及该阶段积累量占总积累量的比例均增加.在江西等双季稻区,建议施氮量以255 kg/hm2,基肥、蘖肥、穗肥的施氮比例以(5∶2∶3)～(4∶2∶4)为宜,具体因品种特性而异.

Double cropping rice in southern China is planted starting from May to the end of October. The pests occur in turn during this period, and the rice planthopper, Cnaphalocrocis medinalis, rice stem borer, and Tryporyza incertulas are the most harmful. In order to obtain high yields, farmers must uninterruptedly use various types of agrochemicals for the prevention and control on the outbreak of pests. In recent years, researchers have studied the phototaxis behaviors of rice pests at night. For example, rice leaf folder, Scirpophaga incertulas, Chilo suppressalis, Sesamia inferens, and Oxya chinensis are more sensitive in the violet light (350-400 nm), and rice gall midge, brown planthopper, and white-backed planthopper are more sensitive in the blue light (470 nm) and green (515-550 nm), while aphids (green), thrips, and tabaci are more sensitive in the yellow light (550-590 nm). The use of black light lamp, double-wave lamp, vibration frequency spectrum lamp, light emitting diode (LED) lamp, and so on can prevent and control rice pest, which have achieved good results. Lighting prevention does not produced any pesticide pollution, pest resistance and high cost compared with the chemical prevention. In this paper, we studied the night life regularity of insects and the rhythm of insects to the searchlight trap. For instance, the activity time of rice planthopper, Cnaphalocrocis medinalis and rice stem borer is from 7:00 in evening to 1:00 in the next morning, rice gall midge, brown planthopper, and white-backed planthopper mainly appear in 8:30-10:30 in evening, and Sesamia inferens usually acts from 10:30 in evening to 1:30 in the next morning. In order to overcome the drawbacks that lights were on all night and beneficial insects were captured by the light, we developed the LED multispectral circulating solar insecticidal lamp that can control time cycle and open different spectral peak lamp to kill the corresponding insect at night, which realized the maximization of luring pests and avoided the trapping of beneficial insects to the greatest extent. All experiments started in May and finished in September, 2015, which were carried out in an experimental field in Jiangxi Agricultural University, Shanggao County, Jiangxi Province (longitude of 115°10’ and latitude of 28°25’). We investigated the quantity damage and rate of rice planthopper, Cnaphalocrocis medinalis, rice stem borer, and Tryporyza incertulas in test and control area. Results indicated that the developed lamp had larger trapping force towards rice pests, and trapped a total of 5 orders, 10 families and 19 species, mainly including Lepidoptera, Pyralidae, Cnaphalocrocis medinalis, stem borer, Tryporyza incertulas, and Plecoptera Delphacidae Laodelphax striatellus, brown planthopper, Sogatella furcifera, Diptera, Culicidae giant mosquitoes and rice gall midge. In addition, there were also a few pests of Coleoptera and straight wing. The percentages of the trapped pest were 32.5% for rice leaf folder, 25.6% for Chilo suppressalis, 25.15% for Tryporyza incertulas, 9.35% for rice planthopper, and 6.90% for other pests. The number of moths and eggs of rice leaf folder and rice planthopper per 667 m2 in rice fields of the light area was 62.5% of that in the control area. The amount of eggs in the light area significantly reduced, and it was not necessary to use agrochemicals for the preventation. The use of agrochemicals reduced by 2 times in the light area compared with the control area in July. This light also killed beneficial insects such as ladybird, ground beetle and grass ridge worm, but the ratio of pest to beneficial insects was 1:0.0089, which had less effect on beneficial insects. Therefore, it is very beneficial to the ecological balance. From the viewpoint of economic efficiency, the costs of agrochemicals and labor decrease significantly. Although the cost of the installation and maintenance is increased, the total cost is decreased. The lamp can effectively kill the rice pests, reduce the amount of pesticides used in the rice growing process and improve the economic efficiency.

随着硒（Se）的开发利用，其营养价值已得到广泛认同。硒为生物生长所需要的微量元素，补硒可以提高生物体免疫力、抗氧化力、生殖力并促进生物体的生长发育，但是受限于硒较窄的营养与毒性的界限，过量补硒反而对生物不利，严重则会导致硒中毒甚至死亡。目前，硒的研究热点集中于营养价值的开发，其潜在的毒性容易被忽略。本文综述了硒对植物、昆虫、哺乳动物以及人类的毒性机制、中毒症状，分析相应的耐硒能力等，并提出当前硒研究的问题和难点以及今后努力的方向，以期全面认识硒并对其进行评估。