中国南部新发现的入侵害虫——银合欢豆象

报道近年发生在我国南部的海南、广西、云南等省区的1种新的入侵害虫——银合欢豆象。经初步调查,该虫严重危害银合欢豆荚和种子。对其形态特征、寄主、分布等进行简要的介绍。     

银合欢豆象生物学特性及其防治

银合欢豆象[Acanthoscelides macrophthalmus(Schaeffer,1907)]是银合欢属Leucae植物种子上的重要害虫,除银合欢外,也可蛀食南洋楹(Falcataria moluccana)种子。在75%RH及20~35℃的条件下,卵期为4～12 d。幼虫期为18～37 d,蛹期为5～11 d。成虫寿命17~31 d,雌雄性别比约为1∶1。在75%RH及26℃条件下,银合欢豆象完成1个世代需要44～48 d。在野外,银合欢豆象在幼龄阶段常被一种姬小蜂科(Eulophidae)的柄腹姬小蜂属(Pediobius Walker)寄生。在75%~80%RH及25～30℃条件下,使用56%磷化铝片剂对银合欢豆象进行熏蒸,用药量7~9 g/m3,熏蒸时间48~72 h,成虫、幼虫及蛹死亡率100%。     

银合欢遗传资源和育种进展

银合欢为豆科含羞草亚科银合欢属木本植物,现发现22个种,其中18个种为二倍体,4个种为四倍体。银合欢栽培种可作于薪材、木料、造纸、木炭、遮荫和绿肥等,已在澳大利亚、印度、巴拉圭、泰国、中国和其它东南亚国家种植。综述了银合欢的种质收集、评价及分类学研究,分子遗传学研究,种间杂交,增加遗传多样性,抗异木虱育种,耐寒、耐霜和耐旱育种,高产优质牧草育种,优质高产木材育种,不结籽树种育种等。     

王草青贮品质研究

研究了不同添加水平的尿素和新银合欢对王草发酵品质的影响。尿素的添加比例分别为0.3%、0.4%和0.5%,新银合欢的添加比例分别为1/3、1/2、2/3和100%,另设100%王草组作为空白对照。试验结果表明,新银合欢添加组的青贮品质均优于尿素添加组。在尿素添加组中,所有添加尿素组和100%王草对照组青贮品质较差,说明王草青贮单独或添加尿素青贮的效果不佳,在实际运用应尽量避免使用这2种方法进行青贮。在新银合欢添加组中,青贮品质由高到低的排列为：1/3新银合欢组、1/2新银合欢组、2/3新银合欢组和100%     

银合欢种子研究进展

随着农业生产对银合欢种子需求的增加,确保银合欢种子的质量成为首要问题。综述近年来对银合欢种子成分、种子萌发、种子保存和种子健康等方面的研究概况,并对银合欢种子研究中存在的问题提出了展望。     

银合欢AFLP分子标记体系的优化

以银合欢幼苗为材料,采用CTAB区室法和试剂盒法2种方法提取DNA,通过对影响AFLP反应关键因子,如DNA样品酶切时间、引物等进行优化,建立了适合银合欢AFLP分子标记的反应体系,为利用AFLP标记对银合欢进行分子生物学研究及分子育种奠定基础。     

银合欢豆象在云南省的潜在分布区预测

为了掌握银合欢豆象在云南的潜在分布区,为银合欢豆象在云南省的发生、早期预警和防控提供参考资料,利用银合欢豆象的分布点数据和环境因子数据,通过Maxent生态位模型预测了银合欢豆象在云南省的适生范围区。结果表明:银合欢豆象在云南省适生范围分为4级,高适生区以绿色表示;中适生区以蓝色表示;低适生区以浅黄表示;非适生区以红色表示。利用ROC曲线分析法对预测结果进行验证表明:其训练数据和测试数据分别为0.995和0.996,远大于随机分布模型的AUC值0.5,说明预测结果可靠。     

红茶菌－嗜酸乳杆菌对银合欢叶的发酵脱毒效果

以银合欢叶含羞草素降解为单一指标.利用红茶菌液、嗜酸乳杆菌液、保加利亚乳杆菌液及植物乳杆菌液为发酵菌液,对银合欢叶的脱毒效果进行研究.以便选取有效的脱毒菌.结果表明,红茶菌液与嗜酸乳杆菌菌液等比例混合液对银合欢叶含羞草素降解效果最好.当菌液接种量为8%,固体密封发酵30d.银合欢叶中含羞草素降解率能达到82%左右,降解效果明显.这为拓宽银合欢的应用具有一定意义.     

世界银合欢研究进展

根据１９９４年召开的国际银合欢专题讨论会的材料，从种质资源、栽培技术、利用技术以及病虫害防治等方面，概述了世界银合欢的研究进展及将来的研究方向。     

新银合欢在浙江的引种试种与适应性研究

浙江引种新银合欢已有10余年。种植的4年生树高达8.36米、胸径10.36厘米。植地分布于北纬29°以南的东南沿海丘陵山地和岛屿。新银合欢能忍耐冬季0℃左右低温霜冻。在极端最低气温-6℃时,地上枝干虽然枯死,但根尚能生长。2—4年生树地上部年生物量达11.97—23.72吨/公顷。3年生树木蓄积量达40.5立方米/公顷。根据树木越冬情况,浙江种植的新银合欢可分为基本常绿型、落叶型、宿根型三种生长类型。     

不同林龄木麻黄沿海防护林林下植被多样性研究

为了揭示木麻黄防护林群落不同演替阶段的物种多样性的变化规律,为中国沿海木麻黄防护林的恢复和重建提供理论依据,采用典型抽样法,选取了海南文昌滨海台地不同林龄的木麻黄(Casuarina equisetifolia)防护林,对林下植物物种组成和植物多样性进行调查研究。结果表明,木麻黄防护林下出现的植物种类为19科31属32种,其中木本植物6科6属8种;草本植物14科24属24种。黑面神(Breynia fruticosa)、马樱丹(Lantana camara)、银合欢(Leucaena leucocephala)、丰花草(Borreria stricta)、白花草(Habenaria dentata)等物种几乎在木麻黄林的各个年龄阶段出现。随着林龄的增加,林下物种总丰富度指数明显在增长。Simpson指数和Shannon-Wiener指数表现为前期物种多样性随林龄的增加而增高,后期稳定不变。说明滨海台地的木麻黄沿海防护林随着林龄的增长,植被群落的生境趋于稳定。     

Effect of season, soil type and fertilizer on the biomass production and chemical composition of five tropical shrub legumes with forage potential

The biomass production and the nutritive value of three tropical shrub legumes with condensed tannins (CT) ( Calliandra calothyrsus , Flemingia macrophylla , Leucaena leucocephala ) and two without CT ( Cratylia argentea , Desmodium velutinum ) as nitrogen-rich feed supplements for ruminants were assessed in two field experiments in Colombia. In one experiment, conducted on two different typical tropical soils (mollisol vs. oxisol; pH, 7·8 vs. 5·0; P content, 43 vs. 2 mg kg DM⁻¹), the effects of low and high levels of fertilizer application with P, K, Ca, Mg and S were tested in both the dry and rainy seasons. In a second experiment on the oxisol, the effect of a lower level of application of either P or S fertilizer was assessed. On the oxisol, C. calothyrsus and F. macrophylla had the highest biomass production (93 and 100 g DM plant⁻¹ in 9 weeks respectively) but the dry season caused extremely low DM yields in all species tested. Leucaena leucocephala did not grow on the oxisol but had the highest biomass production on the mollisol (454 g DM plant⁻¹ in 9 weeks). On the oxisol, the mineral concentrations of the forage were below the requirements of ruminant livestock. Fertilizer treatment had no clear effects on the nutrient composition of the forage. The non-CT shrub C. argentea had the highest concentrations of most minerals in its forage.     

海南热带牧草真菌病害调查(Ⅰ)

对海南省部分牧草病害进行了调查与病原鉴定,发现真菌性病害10多种,其中国内新记录寄主病害8种。为害较重的病害有银合欢黑霉病、山蚂蝗炭疽病、爪哇大豆瘤座孢叶斑病和野花生炭疽病等。     

Nodulation Status and Nitrogenase Activity of Some Legume Tree Species in Bangladesh

Summary

A study was conducted to observe the nodulation status and measure nitrogenase activity of some important legume tree species in nursery. Of the thirteen species surveyed eight belong to Mimoceae, two Papilionaceae and three Caesalpiniaceae. All the species in Mimo-ceae and Papilionaceae were found nodulated whereas all the members of Caesalpiniaceae were non-nodulated. Among nodulated seedlings, highest number of nodules per seedling was recorded in Leucaena leucocephala (82) followed by Acacia auriculiformis (55), Acacia mangium (52), Albizia lebbeck (46), A. procera (41), Dalbergia sissoo (32) and Acacia catechu (29). Nitrogenase activity was highest in L. leucocephla (4913.59 nmole C₂H₄ h^?1) followed by Albizia procera (2080 nmole C₂H₄ h^?1). Seedling height, nodule fresh weight, root fresh weight and nitrogenase activity (per nodule per h, per gram nodule fresh weight per h, per gram root fresh weight per h and per gram root dry weight per h) were also highest in L. leucocephala.     

海南岛油梨树的害虫

记录了海南岛油梨对害虫４３种，并对重要种类角盲蝽、樟脊网蝽、红带蓟马、中喙丽金龟及梨豹蠹蛾的形态、为害特性及生物学作了记述。     

Farmers’ knowledge and perceptions of pests in agroforestry with particular reference to Alnus species in Kabale district, Uganda

Ugandan farmers were interviewed in order to investigate their knowledge, perceptions and ability to manage pests in agroforestry generally and on Alnus species particularly. Farmers’ ability to recognise pest problems on Alnus species was significantly influenced by their length of experience in cultivating the species, but not their age, sex or formal education. Most farmers (77%) were aware of pest problems on Alnus species. However, identification of pest problems was based largely on damage type rather than causal agents. Whereas farmers had good knowledge of vertebrate pests of Alnus, insects and diseases that infest the tree species were unknown to most farmers. Apis mellifera damage on Alnus was the most frequently described damage, but its cause was either unknown or misdiagnosed. Most farmers did not control insect and disease infestations on Alnus because they did not know the causal agents and/or appropriate control measures. Farmers were generally more knowledgeable on insect and disease infestations on crops than on multipurpose tree species (MPTS) and most of them (98%) perceived that crops suffer more damage from such pests than do MPTS. However, farmers’ ability to manage insect pests and diseases seemed weak on both crops and MPTS. Most farmers suggested the use of pesticides to combat pests, but they mentioned only one insecticide, permethrin and one fungicide, mancozeb. More alarming were the suggestions by a few farmers on the use of mancozeb against aphids, and permethrin to combat crop wilt and dieback. Farmers need to be educated about diagnosis, basic ecology and management strategies for both crop and tree pests to ensure sustainable pest control in agroforestry.     

中国剑麻园杂草种类分布危害调查与防控策略

剑麻是我国重要的热带经济作物,杂草危害给剑麻生产带来严重障碍和损失。为了掌握我国广东、广西和海南剑麻园杂草情况,从而进行科学防控。本研究采取踏查和定块系统调查相结合,全面调查了我国剑麻园杂草种类、分布与危害。结果表明,剑麻园共有杂草49科144属200种,其中禾本科40种,菊科24种,豆科20种,茜草科和莎草科各10种;一年生杂草79种,二年生杂草1种,多年生杂草100种,其它生活周期20种;种子繁殖杂草143种,种子、茎和根茎等繁殖杂草57种;外来杂草68种,本地杂草132种;5级危害的杂草3种（大白茅、铺地黍和香附子）,4级危害的杂草7种（牛筋草、短颖马唐、假臭草、阔叶丰花草、加拿大蓬、鬼针草、薇甘菊）。在剑麻园杂草防控方面,提出了"生态优先,以草治草"策略和"不生草的剑麻园不可能是生态剑麻园,只有生良草的剑麻园才可能是生态园"的新观点,并采取剑麻园种草控草、养地、养麻、养畜和驱虫防病的生态化管理技术措施,达到减肥减药、生态安全的可持续发展目标。