Chemical Defense in the Plant Bug Lopidea robiniae (Uhler)

Secretions from the metathoracic glands (MTG) of the black locust bug, Lopidea robiniae (Uhler) (Heteroptera: Miridae) contained six major compounds, including (E)-2-hexenal, (E)-2-hexen-1-ol, (E)-2-octenal, (E)-2-octen-1-ol (E)-2-heptenal, and (Z)-3-octen-1-ol. Males and females did not differ significantly in the relative compositions of identified compounds. In feeding trials, six bird species [robin (Turdus migratorious), blue jay (Cyanocitta cristata), brown thrasher (Toxostoma rufum), killdeer (Charadrius vociferus), starling (Sturnus vulgaris), and house wren (Troglodytes aedon)] demonstrated feeding aversions towards L. robiniae, implying that black locust bugs are chemically defended. Bugs discharged the liquid contents of their MTG when attacked, thereby producing a strong and distinct odor. Some birds immediately ejected bugs out of their mouth after biting them, suggesting that the MTG secretion was a deterrent.     

四倍体刺槐组培瓶苗生根培养研究

应用正交设计法研究6-BA,NAA及琼脂等3个因子对四倍体刺槐组培苗生根率的影响,试验按正交表L16(45)形成3因素、4水平的不同配比。试验结果表明:最佳的增殖培养基是1/2MS+6-BA0.5mg/L+NAA0.1mg/L+琼脂6g/L。     

Tree colonization trends on a sediment bar after a major flood

Tree mortality and regeneration in riparian areas are greatly influenced by flooding. The elevational distribution of Salix spp. and Robinia pseudoacacia were investigated by observing densities and standing conditions before and after a major flood on a sediment bar in the middle reaches of the Arakawa River in Kumagaya, Japan. The subsequent tree recruitment was also examined. R. pseudoacacia was easily washed away with the eroded sediment, whereas Salix spp. was found to be more tolerant. Both species were able to survive even after collapsing, provided that their roots were fully or partially embedded in the sediment. Re‐shooting of collapsed trees, rather than emergence from saplings (either by seeds or vegetative fragments), was observed to be the major method of recruitment after the flood. Therefore, tree density before the flood was unchanged, unless the trees were subject to washing away. Salix spp. recruitment was mainly observed in low‐lying areas and R. pseudoacacia in elevated areas. Recruitment from saplings was species‐specific. Salix spp. at high elevations originated mainly from shoot fragments as they need high levels of moisture for seed germination and at higher elevations, sediment moisture content is very low. R. pseudoacacia, on other hand, originated mainly from roots and seeds. At a given elevation, past recruitment patterns indicated that the annual recruitment of trees increased with tree density up to a particular threshold of recruitment density. Further increases in tree density beyond that optimum value resulted in a decline in recruitment. Furthermore, threshold density was observed to increase along with elevation for R. pseudoacacia while declining with Salix spp. Copyright © 2010 John Wiley & Sons, Ltd.     

微波辅助乙醇提取刺槐花浸膏及其在烟草中的作用评价

利用微波辅助乙醇提取刺槐花浸膏,研究了提取时间对刺槐花浸膏产率的影响,利用GC／MS分析刺槐花浸膏化学成分,共鉴定出14种成分,并且进行卷烟加香作用评价。结果表明：微波辅助乙醇提取刺槐花浸膏在香气质、香气量、杂气、透发性、浓度、细腻柔和、干燥程度、回甜方面均有所提升,余味有变差的趋势。     

刺槐对黄瓜白粉病的防治效果研究

通过室内盆栽和大棚药效试验,研究了刺槐叶片提取物对黄瓜白粉病的防治效果.室内盆栽试验表明,在刺槐提取物浓度为40 mg/mL时,对黄瓜白粉病的防治效果可以达到90.31％,刺槐提取物的EC5o为3.49 mg/mL.随着提取物浓度的增大,发病情况逐渐减轻.大棚药效试验表明,刺槐提取物的浓度为20 mg/mL时,其81.97％的防效高于三唑酮73.61％的效果,每隔7d喷施一次刺槐提取物,能够有效预防黄瓜产果期发生白粉病.     

乙醇提取刺槐花浸膏及其在烟草中的作用研究

利用乙醇提取槐花浸膏,对不同提取温度、不同提取时间对刺槐花浸膏产率的影响及最佳提取时间进行了研究,利用GC/MS对刺槐花浸膏二氯甲烷可溶物进行了分析鉴定,共鉴定出了22种成分。进行了卷烟加香作用评价,结果表明,刺槐花浸膏在增加卷烟抽吸香气量、改善干燥程度方面有作用。     

利用Landsat ETM+数据检测人工刺槐林冠健康

通过发展一种基于单景Landsat TM/ETM+数据客观、可靠、简单易行的人工刺槐林冠健康检测方法,为人工刺槐林地健康监测和管理服务。以孤岛林场的一块近乎纯人工刺槐林地为试验区,首先选择当地刺槐完全展叶时的2000年5月2日的Landsat ETM+数据进行几何精校正,并将第6波段重采样为与第1~5和7波段相同的空间分辨率30 m,然后将波段1~5和7波段数据校正到大气顶层反射率以减少传感器和数据获取方面的影响,利用第6波段计算亮度温度。接着进行3种组合的ISODATA非监督分类（健康或轻度枯梢、中度枯梢、重度枯梢或死亡或灌丛、非植被）：波段1~5和7,归一化后的缨帽变换Tasseled Cap Transform（TCT）绿度和湿度成分,归一化后的缨帽变换Tasseled Cap Transform（TCT）绿度、湿度成分和亮度温度。结果发现,增加了第6波段信息（亮度温度）的第3种组合对人工刺槐林冠健康检测更有效。     

响应面法优化刺槐花多酚的超声提取工艺

目的：利用响应面法对刺槐花多酚的提取工艺进行优化。方法：在单因素试验的基础上,选择温度、超声功率、超声时间、液料比为自变量,多酚提取得率为响应值,利用响应面分析法,研究各自变量交互作用及其对多酚得率的影响,模拟得到二次多项式回归方程的预测模型。结果：刺槐多酚类化合物的提取工艺为温度35℃、超声功率110W、超声时间36min、液料比20:1(mL/g)。结论：在最佳工艺条件下多酚得率为7.891%。     

Allelopathic Potential of <Emphasis Type="Italic">Robinia pseudo-acacia</Emphasis> L.

Robinia pseudo-acacia L. (black locust) is a nonindigenous species currently invading the central part of Japanese grasslands. Several allelochemicals were identified and characterized from the leaf tissue. The growth of both radicle and hypocotyl in the tested species (barnyard grass, white clover, lettuce, and Chinese cabbage) was reduced when grown in soil mixed with the leaves of R. pseudo-acacia at various concentrations. Aqueous leaf extracts, when bioassayed, exhibited a significant suppression of radicle growth. Chromatographic separation of an ethanolic extract of R. pseudo-acacia leaves resulted in isolation of three compounds, identified as robinetin (1), myricetin (2), and quercetin (3) by nuclear magnetic resonance and mass spectroscopy. All inhibited root and shoot growth of lettuce. Robinetin, found in a large amount, caused 50% suppression of the root and shoot growth of lettuce at 100 ppm. The presence of these bioactive substances in leaf tissue suggests a potential role for flavonoids in R. pseudo-acacia invasion in introduced habitats.