低温胁迫下羊蹄甲和洋紫荆家系叶片相对电导率的变化

羊蹄甲Bauhinia purpurea和洋紫荆Bauhinia variegata是羊蹄甲属常见的景观树种,为研究其不同家系的抗寒能力,利用电导法分别对半年生实生苗进行人工低温胁迫试验。结果表明:随着低温胁迫的加重,各家系的叶片相对电导率整体呈上升趋势,且不同家系叶片的相对电导率增长速率不同,表明低温胁迫下各家系叶片的质膜受损程度不同。结合其形态特征变化和后期恢复速度,发现羊蹄甲Y15、洋紫荆G48、G26、G34家系的叶片相对电导率上升幅度较小,低温胁迫后恢复生长情况良好,表明其抗寒性较强。     

Selection of Corymbia citriodora for pulp productivity

Evaluation of a series of spotted gum (Corymbia citirodora) progeny trials, established in the subtropical region of Queensland, Australia, was undertaken to provide information for the development of advanced-generation breeding populations suitable for pulp production. Measurements of growth at two ages were combined with assessments of wood density and pulp yield from a selected sample of provenances to provide comparisons between provenances, to generate genetic parameter estimates and to predict genetic gain potential. Although growth at this age was moderate relative to other eucalypts, the near-infrared predictions of average wood density of 756 kg m^?3 and pulp yield of 55% indicate the species has considerable potential as a pulpwood crop. A pulp productivity breeding objective was used to identify production populations using a range of selection trait weightings to determine potential genetic gain for pulp productivity. Genetic parameters indicated (1) levels of genetic control were moderate for all traits and higher for wood property traits, (2) genetic improvements could be achieved by selection among and within provenances with greater levels of improvement available from selection within populations, (3) genotype by environment interactions were negligible, (4) genetic correlations between traits were favourable, and (5) selection of volume production alone would maximise improvements in pulp productivity.     

利用四斑尼尔寄蝇防治大袋蛾试验

大袋蛾是刺槐、悬铃木、泡桐等树木的主要害虫，食性杂，危害重。利用四斑尼尔寄蝇防治大袋蛾试验，结果表明，在7月中下旬，每公里林带释放四斑尼尔寄蝇6000只，寄生率达到92．7％，叶片保存率82％以上。以虫治虫，一次释放，多年受益，达到了有虫不成灾，保护环境，降低防治成本的效果。     

Improving productivity of Bauhinia purpurea for tree planting farmers in Nepal

Shortage of fodder is a major constraint to livestock production in Nepal. The genetic variation in canopy biomass production of Bauhinia purpurea L, a very important fodder species in Nepal, was estimated in a Breeding Seed Orchard in order to examine the potential of simple, low input breeding. Substantial genetic variation could be observed suggesting that low input breeding based on simple phenotypic selection can provide biomass gain in the order of 2–5% per year. Very high correlation was observed between stem diameter (cross section area) and total biomass, making farmer based selection relevant. Jointly, these results suggest that low input domestication is a promising option for improving fodder production in Nepal and thereby help to improve rural livelihood and development. A multiple population approach is recommended.     

Hypoglycemic effect of Bauhinia cheilandra in rats

The extract of the methanolic leaves of Bauhinia cheilandra (BC) was tested on glucose loaded and alloxan-induced diabetic rats. In both tests, the methanolic extract at doses of 300, 600, and 900 mg/kg, has shown a statistically significant and considerable hypoglycemic activity.     

园林废弃物堆肥对宫粉紫荆袋苗生长的影响

选用黄泥、黄泥︰泥炭=5︰2、黄泥︰园林废弃物堆肥产品=5︰2、黄泥︰园林废弃物堆肥产品︰泥炭=5︰1︰1等4种基质,研究其对宫粉紫荆袋苗生长的影响。综合分析植株株高、叶片叶绿素含量及叶片氮含量3个指标,结果表明:以黄泥︰园林废弃物堆肥产品︰泥炭=5︰1︰1配制的基质对宫粉紫荆生长有最好的效果,其次是以黄泥︰园林废弃物堆肥产品=5︰2配制的基质,说明园林废弃物堆肥产品是园林苗木基质的优良组成材料。     

法国梧桐大袋蛾室内药效试验初报

试验结果表明，试验用5种农药对防治大袋蛾均有效，其中以氰戊菊酯为最好的行之有效的农药，本试验为今后进行防治庭院和行道树法相袋蛾提供依据。     

大袋蛾生物防治技术综合应用研究

大袋蛾是林业的一大害虫。在1998-1999年试验的基础上，2000-2002年在刺槐小片林和林网内对综合生物防治技术进行科技攻关和实践应用研究。试验结果表明，Bt制剂的防治效果达到80％以上；寄生蝇的寄生率在片林中达到25％，在林网中达21％；而大山雀的招引率也很高，平均达70％。3种生物防治方法综合使用后，刺槐片林大袋蛾老熟幼虫平均虫口密度由防治前的47.4头／株下降到防治后的0．39头／株，林网内由46．9头／株下降到0．78头／株，而相似的对照区大袋蛾平均虫口密度刺槐片林为34．8头／株，林网37．6头／株。     

温度对七星瓢虫和多异瓢虫水分散失的影响

七星瓢虫(Coccinella septempunctata)和多异瓢虫(Hippodamia variegata)是新疆棉区棉蚜的主要天敌。为探索2种天敌对温度的适应性,室内设置25℃,30℃,35℃和40℃恒温处理,测定温度对2种瓢虫体内水分散失的影响。结果表明:2种瓢虫水分散失程度对温度响应具有差异性,多异瓢虫散失量高于七星瓢虫,约为七星瓢虫水分散失量的1.7～2.3倍;不同温度处理24 h内,多异瓢虫的死亡率显著高于七星瓢虫(p0.05,df=49)。田间调查结果表明,七星瓢虫与棉蚜有十分明显的跟随关系。因此,七星瓢虫种群崩溃的直接影响因子不是温度,可能与获取食物所得到的水分有密切关系。     

七星瓢虫和多异瓢虫对三叶草彩斑蚜的功能反应研究

研究了七星瓢虫和多异瓢虫在不同猎物密度下对三叶草彩斑蚜的功能反应,结果表明,七星瓢虫和多异瓢虫对三叶草彩斑蚜密度的功能反应可用HollingⅡ方程较好地拟合,经卡平方检验误差不显著（p>0.05）;捕食量在一定范围内随猎物密度的增加而增大;而七星瓢虫和多异瓢虫对三叶草彩斑蚜的捕食量随自身密度的增加而减少,相互之间存在一定的干扰,自身密度的功能反应能用Hassell数学模型较好地反映,经卡平方检验误差不显著（p>0.05）。