利用根蘖苗巧除苹果潜叶蛾

苹果潜叶蛾即金纹细蛾，对苹果树的为害是：幼虫潜入叶背面表皮内取食叶肉，致使叶背被害部位仅剩下表皮，外观呈泡囊状，大小约黄豆粒般，幼虫潜伏其中。叶片正面被害部位则呈黄绿色网眼虫疤。发生严重时，1叶片上约有10个左右的泡囊，使全叶光合作用受到极大影响。导致植株提早落叶，严重影响到树势和生育。     

园林树木施肥应注意的事项（三）

（8）基肥因发挥肥效较慢应深施，追肥肥效较快，则宜浅施，供树木及时吸收。（9）叶面喷肥是通过气孔和角质层进入叶片，而后运送到各个器官，一般幼叶较老叶，叶背较叶面吸水快，吸收率也高。所以实际喷布时一定要把叶背喷匀，喷到，使之有利于树干吸收。     

观赏绿化树木害虫—樱桃类

1 笹木瘤蚜虫 (Tuberocephius sasakii) 沿叶面叶脉筑造袋状黄绿色或浅红色虫肿瘤的蚜虫。切开虫肿瘤,可以看到群棲有长1.6毫米,浅黄色无翅胎生雌虫或幼虫。 在桃花枝条上产卵,以卵越冬,4月上旬在嫩叶展开时孵化,寄生在叶背吸食叶液。寄生部凹陷,叶面出现虫瘤,从5月上旬开始,有翅成虫飞出虫瘤,移居艾蒿,秋季返回桃花上产卵。 形成虫瘤后不易防治,应在孵化期4月上旬喷洒灭蚜松水溶剂(2000倍液)异砜硫磷乳剂100O倍液。2 樱桃瘤头蚜 (Tuaerocephalas sakunae) 樱桃新梢前端的叶片纵向向叶背内侧卷曲,叶片明显萎缩,萎缩叶片很硬,呈紫红色。 无翅胎生雌虫长1.6毫米,暗绿色,在樱花枝条上产卵越冬。4月中旬开始孵化,5～6月造成为害,6月中旬开始长翅膀,移居艾蒿地下茎,秋季返回樱花上。 樱桃花叶虫瘤的识别: 叶片有浅红色袋状虫瘤……笹木瘤蚜叶片萎缩。     

欧洲桤木叶片中氮素浓度的季节变化

桤木有不同时落叶的倾向,直到初冬之前还保持着绿色叶片。绿色叶片的保存,说明了直到落叶之前,叶片中仍保存着有机养分,特别是氮素化合物。大多数冬季落叶的树种,在秋季落叶之前,将大部分叶片中的氮素转移到附近的小枝和枝条内。例如,苹果树在叶片凋落或遭低温冻害之前,叶中氮素失去40—80%。在芬兰,怀诺指出桦木属、杨属、柳属和花楸属的一些树种,在8月初至9月底之间,     

柿小叶蝉的化学防治试验

<正>柿小叶蝉Erythroneura mori Mats,又叫血斑小叶蝉,柿小浮尘子。此虫分布普遍,柿树产区几乎都有发生,主要为害柿树,但枣树、桃、李、葡萄、桑也为害。成虫和若虫栖息在叶背,吸食汁液,被害叶面出现白色小点,严重时全叶呈苍白色,致使柿树提早一个月左右落叶,果实早熟,使柿产量降低。为此,1988、1989连续     

角菱背网蝽的初步研究

角菱背网蝽(Eteoneus angulatusDrake et Maa)属半翅目网蝽科、网蝽亚科,是危害泡桐的重要害虫。为了有效地控制其为害,我们于1979年初至1981年初,在湖南省零陵地区林科所对它进行了初步研究。现总结如下:一、分布和为害角菱背网蝽在湖南零陵地区,长沙市不少地方造成危害,在福建南平市也发现此虫为害泡桐。为害时,成虫、若虫刺吸泡桐的叶、叶柄、枝梢和嫩茎的汁液。受害叶面呈灰白色或淡黄色的斑点,叶背呈褐色斑点。虫口密度大时,一张叶片上有成虫或若虫数     

绿萝的盆栽与养护

绿萝(Scindapsus aureum)又名黄金葛,柚叶藤,为天南星科麒麟叶属多年生藤本观叶植物。绿萝叶似心脏形,全缘,暗绿色,有光泽,叶面上有规则的黄色斑点或斑块,幼苗期叶片较小,色较淡,随着植株生长而长大,叶色变浓绿,叶片增大,因肥水条件差异,其叶片大小有别,叶色有淡绿或深绿。给室     

潮汐对秋茄叶表型塑造及叶经济谱的影响

【目的】明确秋茄叶表型及叶经济谱对自然潮汐生境的响应特征,以期掌握秋茄在周期性浸淹下的适应机制。【方法】对福州市罗源湾秋茄成熟林满潮线上及线下叶片进行研究,以上层未受淹叶片为对照,测定上、下层叶表型性状,并对各性状间关系及叶经济谱进行分析。【结果】与满潮线上层叶片相比,满潮线下层叶片干质量、叶柄长及叶干物质含量较小(P0.01),叶形指数较小(P0.05),比叶面积较大(P0.01);在叶片气孔特性中,满潮线下层叶片气孔长度、宽度、面积、周长、开度、开口长度、开口面积、开口周长均大于上层,而气孔密度则小于上层(P0.01);满潮线下层叶片的净光合速率、蒸腾速率及气孔导度较小,而胞间CO2浓度较大(P0.01),羧化速率较小(P0.01),水分利用效率在满潮线上、下层叶片中差别不显著。满潮线上层秋茄叶片气孔特性与光合功能之间相关性比下层高,而满潮线下层叶气孔特性与叶形态性状相关性高于上层。【结论】秋茄满潮线上、下层的叶表型差异明显,下层叶片气孔功能适应性较强,但光合功能受到一定限制。上层叶气孔特性与光合功能具有协同进化表现,而下层叶气孔特性与叶形态性状存在趋同适应。满潮线上、下层秋茄叶为适应自然潮汐生境,存在明显生存策略选择。叶经济谱表现为:满潮线下层叶片总体上向"缓慢投资-收益型"一端偏移,具有较小的叶干物质含量、气孔密度,较低的净光合速率及较大的比叶面积、气孔面积和气孔开度,以适应周期性低光、缺氧的淹水极端环境;上层叶片则向"快速投资-收益型"一端偏移以应对海岸带大风、海浪拍打等特殊生境。     

贵阳市木兰科树种叶片滞尘效应及影响因素

选择贵阳市不同地点3种木兰科树种为研究对象,应用气溶胶再发生器测定叶片滞尘能力,并用电镜扫描观察比较叶表面微形态,分析其对滞尘能力的影响。结果表明:不同树种叶片表面附着颗粒物能力不同,红花木莲最大,深山含笑次之,白玉兰最低。叶片附着的不同颗粒物PM_(10)、PM_(2.5)占TSP比例分别在40%左右和2%~3%。电镜扫描发现,红花木莲叶表面粗糙,具沟槽、突起、柔毛等结构,气孔密度大滞尘能力较强,白玉兰叶片较光滑、气孔密度较小,滞尘能力弱。生长环境和季节变化对树种的滞尘效应均有一定的影响,市区(河滨公园)滞尘量是郊区(林科院)的1.5倍左右,冬滞尘量最大,而夏季滞尘量最小。     

栽树为什么要记阴阳面

树木向阳面的枝叶,由于长期处在阳光充沛的生态条件下,叶面角质层和栅栏组织较为发达,结构紧密,气孔数目较多.细胞体积较小,光合作用和蒸腾作用都较强.而树木的背阴面,光照弱、温度低、湿度大,则形成与阳面枝叶不同结构的组织.如果移栽时改变了树木的阴阳方     

不同梨品种叶片光合特性及其影响因素研究

以莱阳茌梨、栖霞小香水梨和黄县长把梨为试材,应用CIRAS-II便携式光合测定仪,研究了光合有效辐射、叶龄、叶位和方位对不同梨品种叶片光合特性的影响。结果表明:晴天条件下,所有供试梨品种的净光合速率(Pn)日变化呈不对称双峰曲线;阴天条件下表现为单峰曲线。正面受光叶片的Pn显著高于背面受光叶片。此外,光合速率还受到叶位和叶龄的影响,相同方位外围新梢叶片的净光合速率以基部第7-9叶片最高,且拟合曲线呈抛物线状。Pn随叶龄的增加呈“低—高—低”的趋势,30 d叶龄的莱阳茌梨和栖霞小香水梨叶片具有最大的Pn,而黄县长把梨是40d叶龄。     

严重水分失衡状态下四照花蒸腾表面的削减

应用RGB图像分析的方法,研究了日本山口市街区生长的四照花（Comus kousa Buerg.）对2007年夏季干热多风的环境的响应。结果表明,许多四照花叶尖叶缘出现焦枯,清晰的暗棕色防护带显示在焦枯的叶片上。这些防护带逐渐从叶尖向叶基退缩直到成功控制焦枯为止,且留下许多不成功的防卫痕迹。焦枯的叶片呈现鲜明的逻辑斯蒂函数式变化趋势。依据气象数据分析,四照花叶片退缩型焦枯几乎与干燥峰值期同步。这表明在干燥度突然升高期间,极端的水分亏缺诱发了四照花的防卫反应,从而保护其余部分免于进一步的失水。像素分析结果表明,截止到2007年8月底四照花样树通过局部叶片退缩型焦枯减少了40.2%的叶面积。相比之下,鉴于上半年雨量充足,2008年,相同的样树只有13.2%叶面积减少。不管怎样,四照花的确削减了蒸腾表面积,并且表现出一种独特的蒸腾表面减少方式。既不同于落叶也不同于地上部枯死。依据脱水过程的分析,四照花在突然的干热胁迫下叶尖始发的干缩和叶片防卫反应的共同作用被认为是其蒸腾表面削减的关键所在。     

Influence of clonal susceptibility,leaf age and inoculum density on infections by Melampsora larici-populina races E1 and E3

A study was conducted on the influence of clonal susceptibility, leaf age and inoculum density on the incubation and presporulation periods, and on the intensity of attack of Melampsora larici-populina races El and E3, under controlled conditions, on artificially inoculated poplar leaf discs. Both races were more virulent on susceptible clones and on 5- to 15-day-old leaves. On susceptible clones the intensity of attack increased progressively with the increase of inoculum density. Where there was complete coverage of the leaf surface, uredia were smaller in size as a result of the increase in density. The incubation period and, above all, the average presporulation period of susceptible clones proved to be longer with 1- to 3-day-old leaves and, generally, with the oldest. The epidemiological consequences of these results are discussed.     

构树不同种源叶性状变异研究

【目的】分析构树不同种源叶表型性状遗传变异规律,为构树遗传多样性研究和优良种源的筛选等提供参考。【方法】以30个构树种源的叶为材料,通过测量叶面积、叶长、叶宽、叶周长等8个叶的表型性状,进行综合分析。【结果】1)构树不同种源间8个叶表型性状的差异均达到极显著水平,且性状间具有显著的相关性,叶面积与叶长、叶宽、叶周长、叶柄长和绒毛密度均呈极显著正相关。2)不同叶片性状间变异系数幅度为12.72%~64.50%,该结果初步表明不同种源间叶片性状的遗传变异幅度较大,叶面积、叶长、叶宽和叶周长的种源重复力均在55%以上,表明构树的叶性状差异在一定程度上是受遗传控制的。3)对不同种源建立叶面积拟合方程,除四川大邑外,其他种源的叶面积拟合方程的相关系数均在0.8以上,说明这些模拟方程的拟合效果较好,后续试验可通过叶长与叶宽预测叶面积,简化试验。4)对构树叶各性状与地理、气候因子进行相关分析,叶面积、叶长、叶宽、叶周长和绒毛密度与经度呈显著负相关,与纬度呈极显著负相关,说明种源间构树叶的地理变异是以纬度变异为主。5)根据叶片的8个性状可将30个构树种源聚为3类。【结论】构树不同种源间叶表型性状差异显著,可为构树遗传多样性研究和优良种源的筛选提供参考。     

Influence of light availability on leaf structure and growth of two Eucalyptus globulus ssp. globulus provenances

Light availability strongly affects leaf structure of the distinctive ontogenetic leaf forms of Eucalyptus globulus Labill. ssp. globulus. Late-maturing plants from St. Marys, Tasmania and early maturing plants from Wilsons Promontory, Victoria (hereafter referred to as Wilsons Prom.) were grown for 9 months in 100, 50 or 10% sunlight. Growth, biomass and leaf area were significantly reduced when plants were grown in 10% sunlight. Provenance differences were minimal despite retention of the juvenile leaf form by the Tasmanian plants throughout the study. The time taken for initiation of vegetative phase change by the Wilsons Prom. saplings increased with decreasing light availability, but the nodal position of change on the main stem remained the same. Both juvenile and adult leaves remained horizontal in low light conditions, but became vertical with high irradiance. Leaf dimensions changed with ontogenetic development, but were unaffected by light availability. Juvenile leaves retained a dorsiventral anatomy and adult Wilsons Prom. leaves retained an isobilateral structure despite a tenfold difference in light availability. Stomatal density and distribution showed ontogenetic and treatment differences. At all irradiances, juvenile leaves produced the smallest stomata and adult leaves the largest stomata. Amphistomy decreased with decreasing irradiance. Detrended, correspondence analysis ordination highlighted the structural changes influenced by ontogenetic development and light availability. Adult leaves had characteristics similar to the xeromorphic, sun-leaf type found in arid, high-light conditions. Although juvenile leaves had characteristics typical of mesomorphic leaves, several structural features suggest that these leaves are more sun-adapted than adult leaves.     

木兰青凤蝶生物学特性的初步研究

木兰青凤蝶[Graphiumdoson(FelderetFelder)]在浙江1a发生3～4代,以蛹在叶背越冬。以幼虫为害广玉兰、含笑的嫩叶、芽,成虫4～10月份均有发生,卵散产于嫩叶正面的叶缘,一般1叶1卵,偶见2卵,幼虫共5龄,5龄幼虫为害最烈,1d能取食4～6张含笑嫩叶,老熟幼虫在老叶背面化蛹,第2代部分蛹有滞育越夏现象。     

Sclerophylly and leaf anatomical traits of five field-grown olive cultivars growing under drought conditions

Leaf-level morphological and structural adaptations to reduce water loss were examined in five olive (Olea europaea L.) tree cultivars (Arbequina, Blanqueta, Cobran?osa, Manzanilla and Negrinha) growing under field conditions with low water availability. Leaf measurements included leaf tissue thickness, stomatal density, leaf area, leaf mass per unit area, density of leaf tissue, relative water content, succulence, water saturation deficit, water content at saturation and cuticular transpiration rate. We found considerable genotypic differences among the cultivars. Negrinha, Manzanilla and Cobran?osa had more morphological and structural leaf adaptations to protect against water loss than the other cultivars. Manzanilla and Negrinha enhanced their sclerophylly by building parenchyma tissues and increasing protective structures like the upper cuticle and both the upper and lower epidermis. Cobran?osa exhibited good protection against water loss through high density of foliar tissue and by thick cuticle and trichome layers. Compared with the Negrinha, Manzanilla and Cobran?osa cultivars, Arbequina leaves had a thinner trichome layer, implying that the leaves were less protected against water loss; however, the development of smaller leaves may reduce water loss at the whole-plant level. Among cultivars, Blanqueta had the largest leaves and some anatomical traits that may lead to high water loss, especially from the adaxial surface. The mechanisms employed by the cultivars to cope with summer stress are discussed at the morpho-structural level.     

Physiological defence reactions of young beech trees (Fagus sylvatica) to attack by Phyllaphis fagi

The physiological reaction to attack by the lachnid Phyllaphis fagi compared with non-infested control plants was examined in whole leaves and leaf phloem of beech (Fagus sylvatica) saplings as well as in beach seedlings cultivated in different nutrient substrates. The colonisation density of the lachnids on beech seedlings increased with improved nutrient supply. However, growth was not depressed to a comparable extent. Defence reactions were found at three hierarchic levels. Infested plants exhibited a strongly decreased amino acid/monosaccharide ratio in the entire leaf and leaf phloem. In addition, secondary plant defence substances were detected in beech saplings and lamma shoot leaves of beech seedlings. A systematic reaction, dependent on the infestation density of the lachnid was observed in the leaf phloem of the beech saplings.     

Responses of decomposition of green leaves and leaf litter to stand density,N and P additions in <Emphasis Type="Italic">Acacia auriculaeformis</Emphasis> stands

The effects of nitrogen (N), phosphorus (P) and N?+?P additions on the decomposition of green leaves and leaf litter were studied over 2 years using the litterbag technique in Acacia auriculaeformis stands with different densities in southern China. The green leaves and leaf litter were treated with four fertility treatments: control, N addition, P addition and N?+?P addition to test the effect of stand density and fertility on the decomposition of green leaves and leaf litter. The mean percentage of mass remaining (PMR) of green leaves and leaf litter significantly decreased with increasing density. Nitrogen and N?+?P additions had a negative effect on PMR, whereas the addition of P had a positive effect. The rapid decomposition of green leaves was associated with a higher N and P content and a lower N/P ratio, indicating a likely P limitation for A. auriculaeformis stands. Our results imply that stand density associated with canopy openness can impact litter decomposition, and P is an important control factor on litter decomposition in A. auriculaeformis stands.     

Outbreak of powdery mildew caused by Sawadaea negundinis on boxelder in Iran

Boxelder (Acer negundo) is planted as ornamental and shade tree in many countries including Iran. During July 2016, boxelder trees in parks and streets of different localities in East Azarbaijan province, Iran were found to be heavily infected with powdery mildew. Whitish powdery fungal mass developed mainly on the lower leaf surface. The infected young leaves became bubbled, curled and crinkled, giving affected plants an unpleasant appearance. During September, scattered, dark brown, spherical chasmothecia were produced on the lower leaf surface. The causal agent was identified as Sawadaea negundinis based on a combination of morphological characteristics of sexual and asexual morphs and sequence data of the rDNA internal transcribed spacer region (ITS1‐5.8S‐ITS2). This study provides the first report on the occurrence of S. negundinis on boxelder in Iran.