Influence of slope position, stand type and rhododendron (Rhododendron ponticum) on litter decomposition rates of Oriental beech (Fagus orientalis Lipsky.) and spruce [Picea orientalis (L.) Link]

Oriental beech (Fagus orientalis Lipsky.) and Oriental spruce [Picea orientalis (L.) Link] are the two most common tree species in northeast Turkey. Their distribution, stand type and understorey species are known to be influenced by topographical landforms. However, little information is available as to how these changes affect litter decomposition rates of these two species. Here, we investigated the effects of slope positions (top 1,800 m, middle 1,500 m and bottom 1,200 m), stand type (pure and mixed stands) and purple-flowered rhododendron (Rhododendron ponticum) on litter decomposition rates of Oriental beech and spruce for 4 years using the litterbag technique in the field. Among these three factors, stand type had the strongest influence on litter decomposition (P < 0.001, F = 58.8), followed by rhododendron (P < 0.001, F = 46.8) and slope position (P < 0.05, F = 11.6). Litter decomposition was highest under mixed beech/spruce forest, followed by pure beech and spruce forest. Beech and spruce litter decomposed much faster in mixed bags (beech–spruce) than they did separately under each stand type. Purple-flowered rhododendron significantly reduced litter decomposition of Oriental beech and spruce. Beech and spruce litter decomposed much slower at top slope position than at either bottom or middle position. Differential litter decomposition of Oriental beech and spruce was mainly due to adverse conditions in spruce forest and the presence of rhododendron on the ground which was associated with lower soil pH. Higher elevations (top slope position) slowed down litter decomposition by changing environmental conditions, most probably by decreasing temperature as also other factors are different (pH, precipitation) and no detailed investigations were made to differentiate these factors. The adverse conditions for litter decomposition in spruce forest can be effectively counteracted by admixture of beech to spruce monoculture and by using the clear-cutting method for controlling rhododendron.     

百合鳞片无土扦插小子球分生动态研究

以东方百合索蚌(Sorbonne)的鳞片为试材,采用Hoaglang与Amon 1938年提出的营养液配方Y1(N:P:K=15:1:6)和对照(CK)去离子水处理,研究了小子球分生、新根和新叶产生动态.结果表明,小子球分生大多在鳞片愈伤组织腹内侧1～2 mm处,呈线状规律排列,愈伤组织(伤口)与腹背产生较少,仅占1%左右;营养液和对照两种培养方法,子球的分化期都集中在破球扦插后的3～4周,以后子球的数量不再增加;营养液无土扦插较对照去离子水培养,子球产生高46.74%,差异极显著;新根的分化集中在破球前1～4周,但破球后的生长期内仍有新根产生;新根产生较对照高35.69%,差异极显著.营养液培养下,子球分生较新根早,而对照根的发生则先于小子球,但新叶产生较早,比对照提早2周,差异显著.     

东方百合鳞片组织培养研究

以鳞片为外植体,研究了7个东方百合品种的组织培养方法。结果表明,东方百合不同品种之间鳞片不定芽的分化率以及单个外植体上再分化不定芽的数量存在显著差异,以西伯利亚最高,分化率为68．04％,瑞塔较低,仅为12．96％,索蚌最差。不同部位鳞片不定芽的分化率也存在显著差异,分化能力由大到小依次为中层、外层、内层。适宜东方百合鳞片不定芽分化和增殖的最适培养基为MS＋6-BA0．50mg／L＋NAA0．05mg／L,不定芽生根最适培养基为1／2MS＋NAA0．20mg／L。     

柑橘园柑橘小实蝇入侵扩散规律与危害动态模型研究

为了探索柑橘小实蝇入侵扩散与危害规律,提高其监测与防控水平,2008-2010年应用柑橘小实蝇专用性诱剂和诱捕器,在全市19个镇（街道）35个柑橘园建立监测点进行全市性入侵扩散分布普查;在古城伏龙柑橘园和市区水果市场建立2个系统监测点开展全年种群数量消长监测,结果表明柑橘小实蝇种群入侵扩散与时空分布呈塔型趋势,即以城区为中心,并呈向周边区域扩散蔓延趋势;全年种群时序数量变化主要呈单峰型曲线变化,一般于6月中下旬至7月上中旬初见性诱成虫,8月上旬形成增长拐点,9-10月形成数量高峰, 影响种群数量消长的主要因子有种群基数、气候和生境条件等,从而创建柑橘小实蝇基数（m6）与全年种群诱量（M）关系模型M=23.8339 m6+59.8003（n=6, r=0.9735**）、当旬虫口密度(mn)与其前3个月的旬平均气温(tn-9)关系模型mn=1.9248tn-9-14.88063（n=72, r=0.5123**）,以及柑橘挂果期成虫诱量（M）、有虫株率（R%）、有虫果率（P%）、每虫果幼虫量（N）等关系模型：R=0.3667M-1.2746（n=11, r=0.8901**）;P=0.0581R+0.3112（n=11, r=0.9649**）;N=0.6438P+0.9610（n=11, r=0.7000*）。应用柑橘小实蝇种群入侵扩散危害规律及其参数模型,可反映柑橘园柑橘小实蝇发生变化动态,可随旬作出预报和决策防治,这对提高其监测预警和持续控制具有重要指导意义。     

种植密度对东方百合“西伯利亚”生长及切花品质的影响

为了研究不同种植密度对东方百合"西伯利亚"生长及切花品质的影响,试验选用周径16～18 cm的东方百合"西伯利亚"为试材,分别设32株·m2(处理A)、44株·m-2(处理B)、52株·m-2(处理C)3个种植密度处理.结果表明,不同种植密度下的东方百合"西伯利亚"生长发育进程的总体趋势基本一致,种植密度对东方百合"西伯利亚"生长发育进程的影响主要出现在植株生长发育的中后期,但处理间的差异不显著;种植密度对东方百合"西伯利亚"的生物学性状具有一定影响,其中处理A的叶片数、比叶重、基根均长以及茎根均长都显著高于处理C;种植密度对东方百合"西伯利亚"的干物质积累和分配存在一定影响,除了切花产量之外,不同种植密度下的东方百合"西伯利亚"的其他切花品质指标虽然存在一定差异,但均不显著.因此,适当密植不仅对东方百合"西伯利亚"的生长和切花品质不会造成较大的影响,而且还可以有效地利用各种资源,增加单位面积的切花产量,进而提高切花生产企业的经济效益.     

基于层次分析法的盆栽东方百合品种综合评价体系构建

[目的]建立盆栽东方百合品种综合评价体系,筛选出适合广西地区规模化设施栽培的优良百合品种.[方法]观测统计12个盆栽东方百合品种的20个植物学性状指标,应用层次分析法从花性状、茎叶性状和生长适应性3个方面构建盆栽东方百合品种的综合评价体系.[结果]通过对花性状、茎叶性状和生长适应性赋权,确定评价20个性状指标的权重值,其中叶烧情况、成花率、花径、落叶情况和株型紧凑度的总排序权重所占比重较大,分别为0.1429、0.1372、0.1139、0.0714和0.0677;根据品种综合评价得分,将12个东方百合品种划分为优秀、优良、一般和较差4个等级,其中,Entertainer、Starlight express、Souvenir、Bahamas和Pink champion 5个品种综合性状表现优良,适合小规模生产;Fortune和After eight综合性状表现差,可淘汰.[结论]东方百合品种Entertainer、Starlight express、Souvenir、Bahamas和Pink champion具有花朵硕大、花色艳丽、花期长、株型紧凑和适应性强等优点,可作为广西地区设施盆栽百合品种引进推广.     

东方百合不同外植体愈伤组织诱导效果

对东方百合Tiber品种的多种外植体进行了组织培养试验,研究结果表明,在不同激素浓度条件下,东方百合Tiber品种不同外植体的组织培养效果不同,诱导形成愈伤组织在数量、质量和时间上具有明显的差异,形成愈伤能力大小依次为:幼嫩鳞茎>花托>鳞片>叶柄>叶片。     

利用性诱剂防治梨小食心虫的研究试验

采用性诱剂对梨小食心虫进行防治研究,结果表明,梨小食心虫在晋中地区1年发生4代,可在成虫高峰期进行化学防治;15个/hm2诱盆用于梨小食心虫大量诱捕试验中,可在72d内平均每盆诱虫900头;1050,750个/hm2诱芯的迷向处理迷向率极显著,迷向率分别为97.43%和81.83%,防治效果为74.72%和56.43%。并对梨小食心虫性诱剂的应用提出了几点建议。     

东方白鹳国内圈养种群的统计分析

应用种群管理软件SPARKS 1.5及PM 2000 v1.214对东方白鹳的国内圈养种群进行统计分析。在有记录的36 a人工圈养的历史中,野外捕获个体在1975～1999年间是构成圈养种群的主要部分,自1984年首个圈养个体出生后,圈养出生个体数量以年平均增长率15.10%速度增长,至2000年取代野外捕获个体数量,成为目前种群发展的主要力量。截至2009年12月31日,我国共有61家动物园或机构圈养了375只东方白鹳个体。种群周期增长率λ=1.0311,性别比例为雄性：雌性=0.927 8,现有种群中能够繁殖的个体共25只（雄性13只,雌性12只）;种群遗传多样性指标GD=95.44%,平均近亲系数F=0.031 6。为了保证东方白鹳国内圈养种群的自我维持,促进种群的健康发展,建议开展未知性别个体的性别鉴定工作、建立种群发展规划并进行合理的宏观调控。     

Effect of Chloride in Irrigation Water on Oriental (Sun-Cured) Tobacco

ABSTRACT

Responses of tobacco (Nicotiana tabacum L.) to chloride vary according to tobacco types, cultivars, and methods of fertilization, cultivation, and harvesting used. Until now, research has focused on types other than Oriental. In this work, the effect of chloride concentration (10 to 80 mg L^?1) in irrigation water on growth and agronomic and chemical characteristics of Oriental tobacco was evaluated with a three-year (1999–2001) outdoor pot experiment. Whether Oriental tobacco cultivars, aromatic and neutral, respond differently to chloride was also investigated. The results showed that the influence of chloride on growth-development and total cured leaves yield on Oriental tobacco was inconsistent and substantial only in neutral cultivars. The increased cured leaves yield in neutral cultivars with 50 mg Cl L^?1 was attributed mainly to the increased size of leaves. Leaf chloride concentration increased linearly with the increase of chloride level in irrigation water, but the leaf chloride concentration and the rate of linear increase were highest in the upper leaves of the plant, and decreased gradually from the upper to the lower leaves. Generally, the optimum chloride level in irrigation water was found to be below 20 mg L^?1, whereas the 40 mg L^?1 level was the critical upper threshold to avoid adverse effects on Oriental tobacco. The six cultivars showed different accumulation rates of chloride in leaves, and these rates were affected differently by the increased chloride in water. The changes in chemical characteristics examined concerning cured-leaf product quality were minor. The results indicate that one may choose among cultivars, either aromatic or neutral, in order to limit the adverse effects of irrigation with water containing increased chloride concentration.