杨干象虫防治技术的研究

通过采用高渗透对硫磷点涂杨干象幼虫期取食刻痕的试验,结果表明:5倍液的高渗透对硫磷对杨干象幼虫杀虫效果最好,平均达到99.9%,防治时间以5月10-20日进行效果最好。     

灭幼脲对杨干象作用机制和防治的研究

采用灭幼脲油剂，油胶悬剂等，用点涂的方法对杨干象幼虫和成虫进行了适时防治，结果表明：灭幼脲油剂可抑制表皮几丁质的合成达１５％以上；灭幼脲油胶悬剂抑制杨干象成虫精巢和卵巢的发育，可使成虫产卵间降低４０－７０％，使卵的孵化率降为零。这为杨干象的防治找到一条高效，安全，经济，易全文的新途径。     

杨树对杨干象抗性选择的研究

在杨干象危害80％以上的人工杨树林内,以抗杨干象、速生等综合指标,选出了抗虫优树。对3年生优树后代室内外人工接种和自然感染的结果表明:106号优树比周围3株优势水平均胸径高9％,树高高7％,材积高61％,室内接种其诱虫数、取食孔数都低;野外接种,虫株率低40％以上,危害指数低69％;自然感染的虫株率低54％,危害指数低50％以上。优树生长量较对照原种中东杨(Populus berolinensis)高得多,但低于小黑杨(P.×xiaohei)。其抗虫性与树皮内含物果糖和酚酸含量有关。     

杨干象成虫补充营养及在杨树幼林内的扩散

在培养皿和养虫笼内放吸附糖酒醋、蜜酒醋及水３种营养液的棉球，观察杨干象成虫取食每种营养液的情况，其结果表明杨干象最喜欢以糖酒醋作补充营养。杨干象在杨树幼林内自虫源地一方的林缘向林内逐渐扩散，幼林边行的虫口密度最高，为整个林分虫口密度的４５．２％，自林缘至６６ｍ间的虫口密度为整个林分虫口密度的９１．０％。     

板蓝根提取物对果蝇的杀虫作用

为了探究不同浓度的板蓝根提取物对果蝇生长发育的影响,采取对照组果蝇喂食正常的玉米粉-酵母培养基,实验组喂食含有4%和8%的板蓝根提取物的正常培养基的方法,分别检测不同浓度板蓝根提取物对果蝇的生长速率、发育时间、结蛹率、羽化率、蛹大小、成虫大小、成虫翅膀面积、幼虫翅原基面积及成虫寿命的影响。结果表明:喂食低浓度的板蓝根对果蝇的生长发育没有产生影响,喂食8%板蓝根使果蝇的生长速率、发育时间明显延缓,结蛹率、羽化率、蛹大小、成虫大小、成虫翅膀面积、幼虫翅原基面积以及成虫寿命明显降低的现象。此结果说明高剂量的板蓝根能够显著抑制果蝇的生长发育和生存率,为板蓝根作为新型植物源杀虫剂提供理论基础。     

机油、氧化乐果混配制剂对杨干象防治效果的研究

文章阐述了机油与氧化乐果混配制剂对杨干象防治试验效果,结果认为:1份机油加10份氧化乐果和10份水的比例,对速生杨进行涂干防治杨干象幼虫危害效果最好,防治效果达到了99.2%,药害率为零。     

植物生物碱的杀虫作用及应用

植物生物碱是植物在与昆虫协同进化过程中形成的一大类具有防御功能的次生代谢物质,在害虫综合治理中具有非常重要的作用。本文对植物生物碱的杀虫作用方式、作用机理和作为杀虫剂、昆虫拒食剂、驱避剂、产卵忌避剂的应用以及作为先导化合物在新农药创制中的作用做了综述,并对植物生物碱的研究前景进行了展望,提出了今后研究和开发应用中注意的问题。     

NaCl胁迫对露水草种子萌发与幼苗生长及β-蜕皮激素含量的影响

对不同浓度NaCl处理下露水草种子发芽、幼苗生长及蜕皮激素含量的差异进行研究的结果表明,较低浓度NaCl可促进露水草种子发芽,而较高浓度则抑制其发芽。25、50、75和100 mmol/L浓度NaCl处理的发芽指数较对照分别下降15.81%、40.57%、59.33%和81.94%,种子活力指数分别下降了7.73%、12.69%、30.69%和61.28%。随着NaCl浓度的增加,幼苗茎长与根长呈下降趋势,当NaC1浓度50 mmol/L时,各处理间的茎长和根长明显受到抑制。露水草根部蜕皮激素含量较对照分别下降了3.21%、7.91%、34.8%和53.63%,地上部分的蜕皮激素含量较对照分别下降6.12%、57.14%、69.39%和77.55%,其中地上部分蜕皮激素含量的影响大于地下部分,由此表明高浓度的NaCl对露水草地上部分蜕皮激素含量形成具有明显的抑制作用,为提高其蜕皮激素产量,应避免在高含量NaCl土壤中种植露水草。     

2种植物源药剂对松丽毒蛾幼虫应用效果

为明确1.3%苦参碱可溶液和1.2%烟碱·苦参碱乳油喷烟防治松丽毒蛾幼虫的林间最佳配比和用药量,在三明市三元区岩前镇、莘口镇的马尾松林建立试验区开展林间防治试验。结果表明:药后3 d,施用2种药剂的松丽毒蛾幼虫死亡率达85.6%以上,1.3%苦参碱可溶液和1.2%烟碱·苦参碱乳油2种药剂与烟雾剂最佳配比均为V(药剂)︰V(烟雾剂)=1︰9,林间最佳用药量分别为750 mL/hm^(2)和600 mL/hm^(2)。2种植物源药剂喷烟防治松丽毒蛾幼虫均有良好效果。     

植物次生性物质对植食性昆虫的抗虫作用及其分析方法

植物次生物质是一种十分重要的抗虫物质,它对植食性昆虫具有驱避、抑食、毒害作用。此外还对昆虫的天敌具有引诱作用。在植物次生物质的分析手段方面,主要包括色谱法和波谱法。在实际应用过程中,二者常是结合在一起使用的,色谱-波谱联用技术在植物次生物质分离分析过程中已经成为不可缺少的工具。     

Research advances in allelopathy of Quercus L.

The term allelopathy refers to biochemical interaction between all types of plants including microorganisms through pro-duction of chemical compounds that escape into the environment and exist widely in Quercus L. The development of investigations into types of allelochemicals, their compounding and spreading pathways, as well as expression of allelopathy in Quercus L. are re-viewed in this paper. We have closely and systematically emphasized the functional mechanisms of allelopathy in forest plants for our next research project on allelopathy in Quercus L.     

Intraspecific variation in <Emphasis Type="Italic">Trifolium pratense</Emphasis>: impact on feeding and host location by <Emphasis Type="Italic">Sitona lepidus</Emphasis> (Coleoptera,Curculionidae)

Red clover (Trifolium pratense L.) is becoming increasingly important in grassland systems because of its high productivity, protein content and nitrogen-fixing ability, but its use has been constrained by losses due to pests and diseases, and this contributed to the decline of red clover usage allowing white clover (T. repens L.) to become the dominant legume of UK grasslands. One of the major pests of red clover is the clover root weevil (Sitona lepidus Gyllenhal, Coleoptera, Curculionidae) which attacks both the shoots and roots, particularly the N-fixing root nodules, of clover plants. This current work investigates the feeding preferences of S. lepidus with respect to 11 varieties (Pawera, Kuhn, Astra, Norseman, Norseman low, Norseman high, Marcom, Merviot, Milvus, Britta, Sabtoron) and 5 lines (AA30, AA31, AA4493, AA4494 and AA4495) of red clover in order to identify relationships between the variation in attractiveness of different red clover varieties for both adult and larval stages of the weevil. Of those tested Norseman high showed potential resistance, being less favoured by both adults and larvae of the weevil. This may be attributed to the potentially high phyto-oestrogen levels in this variety.     

Extraction of <Emphasis Type="Italic">Trigonella foenum-graecum</Emphasis> L. by supercritical fluid CO<Subscript>2</Subscript> and its contact toxicity to <Emphasis Type="Italic">Rhyzopertha dominica</Emphasis> (Fabricius) (Coleoptera: Bostrichidae)

Rhyzopertha dominica (Fabricius) has developed extensive pesticide resistance in the last several decades. We have developed a supercritical fluid extraction method for Trigonella foenum-graecum L. (TFG) and studied the contact toxicities of the extracts to R. dominica. The extraction method was designed with orthogonal experiments to preserve and collect all the possible active components. Contact toxicity and efficiency of extraction were used as standard values to optimize extraction conditions, which were achieved at 55°C under 25 Mpa of pressure. The extraction efficiency for 200 g of dry sample reached 6.21% with 30 ml of 95% alcohol. Extracts loaded on filter paper showed dose and time dependent toxicities to adult R. dominica with a LC₅₀ value of 65.02 μg/cm² after 3 days post treatment. Our extensive in vivo studies indicated the extracts from Trigonella foenum-graecum seeds have high efficacy against pesticide resistant R. dominica. The active ingredient(s) from the extract shows promise as a novel pesticide candidate.     

Vitality and storage condition of Syringa pollen

The fresh pollen vitality,the effect of different storage conditions on the pollen vitality,and the difference of vitality among the species of seven species of Syringa were determined in Shenyang,China.The results indicated that the pollen vitality (81.5%) of Syringa villosa was the highest among the seven tested species,followed by S.microphylla and S.meyeri,and that of S.oblata var.affinis was the lowest.The low temperature was the best condition for storage of pollen of Syringa,and the most proper temperature for the storage was 0-2℃.The storability of S.microphylla was the best of all,and it could be stored over 60 days at the temperature of 0-2℃,next was S.villosa and S.meyeri.     

Embryo culture and rapid propagation of Syringa

Embryo of lilacs (Syringa L) culture in vitro and the rapid propagation were studied. The orthogonal experiments, including the selection of basal medium, embryo age and other factors such as sugar, benzyladenine (BA), naphthalene acetic acid (NAA) and glutamine (Gln), were carried out. The results indicated that the optimal medium for embryo culture was Monnier medium supplemented with NAA (0.001 mg.L^-1), BA (0.1 mg.L^-1), sugar (50 g.L^-1), and Gin (400 mg.L^-1), with a germination rate of 91.7% at least; the optimal embryo age was 50 d; and Gln had significant effects on the germination rate of embryo.Moreover, the optimal medium for subculture was MS BA (2 mg.L^-1) NAA (0.001 mg.L^-1) Gln (0.5 mg.L^-1), with the propagation coefficient of 3.6 at least.     

思茅松天然群体的遗传多样性及遗传分化

采用凝胶电泳技术,检测了思茅松(Pinuskesiyavar.Langbinaensis)种子胚乳的9种同工酶。通过对9种酶系统编码的16个酶位点的遗传分析,揭示了思茅松三个天然群体的遗传多样性和遗传分化情况。思茅松天然群体的遗传多样性较高,群体的多态位点比例为0.667;平均每个位点的等位基因数为2.13;期望杂合度和观察杂合度分别为0.288和0.197。群体间的遗传分化程度较低,分化系数仅为0.052,群体间的遗传距离为0.015。表5参15。     

Analysis on age structure of Zoysia japonica（Poaceae） population

The age-structure of natural population of Zoysia japonica in Xiuyan County of Liaoning Province was studied by generational method.The results showed that the highest tiller age class was three,but 1st age class tillers held dominant position with proportions over 95% in each month during the growing seasons.The 2nd age class and 2rd age class tillers were minority in the population.So Z.japonica population was an expanding population.The zero age class buds on the rhizomes were dominantin buds age structures.The proportion of buds to tillers on quantity in each month was about 30% to 40% and reached the highest at the end of September.The increasing of buds proportion before dormancy guaranteed the quantity of tillers in the next spring.The biomass of 1st age class tillers changed with time.The biomass kept increasing from April to July and reached the highest at the end of July and then decreased.     

Research advances in the study of Pistacia chinensis Bunge, a superior tree species for biomass energy

As a renewable energy, biomass energy has aroused wide attention and studies of this issue have become a hot topic throughout the world. Pistacia chinensis Bunge (Anacardiaceae) is a superior species for biomass energy with high oil content in seeds and wide geographic distribution. It is a dioeciously, deciduous arbor, flowering from March to April and bearing fruits from September to November. The classification, regional distribution and biological characteristics of P. chinensis are stated in this paper, then, research advances in the growth, breeding and physiology of this species are summarized. The problems in present studies are broached. Finally, a future direction for research is proposed.     

Contamination and browning in tissue culture of Platanus occidentalis L.

Twigs of 2–3-year-old Platanus occidentalis L. were used as experimental material to find the causes for the contamination and browning in the initial stages of tissue cultures. To compare the degree of browning of explants picked off from different growing seasons, the experimental material was excised from trees on each of the first ten days in January, March, May and July, 2006. The results indicated that the contamination and browning rates of the material cut off in January (14.2% and 30.6%, respectively) and March were somewhat lower than those in July. The pretreatment of soaking the explants in different anti-oxidants and absorbents at the same time could diminish some side effects. The pretreatment of using 10 g·L–1 vitamin C reduced the contamination and brown-ing rate effectively. An orthogonal experiment showed that the optimal factor and level arrangement is 0.5 mg·L–1 BA, 2.0 g·L–1 ac-tive carbon and 1.5 g·L–1 PVP which resulted in a browning rate of only 16.5%. In general, sampling period, physical properties and pretreatment of explants are the main factors responsible for the contamination and browning of material in the initial stages of P. occidentalis tissue cultures.     

Agrobacterium-mediated genetic transformation of Camptotheca acuminata

UGPase gene related with wood cellulose synthesis was transferred into C. acuminata using the method of Agrobacte- rium-mediated genetic transformation, and an efficient transformation system was developed for C. acuminata on the basis of evaluations of several factors affecting Agrobacterium-mediated DNA transfer rate. The highest transformation rate was achieved when pre-cultttred leaf explants were infected with an Agrobacterium culture corresponding to OD600 （0.5） for 10 min, and cultured on explant regeneration medium for three days. The results of Southern hybridization showed that genomic DNA of the kanamycin-resistant shoots to an UGPase gene probe substantiated the integration of the transgene. Transformation efficiency （6%） was achieved under the optimized transformation procedure, This system should facilitate the introduction of important useful genes into C, acuminata.