山荆子全光喷雾扦插育苗试验

以清水为对照,试验研究了ABT1号和"根太阳"生根剂分别在2种浓度下对山荆子全光喷雾扦插繁殖的扦插成活率,苗木根系数量、长度、直径的影响,结果表明,不同处理和对照扦插苗平均成活率22.2%～51.1%,"根太阳"生根剂50倍液(X4)成活率最高,显著高于对照和其他处理(p<0.05);不同处理和对照扦插苗单株平均根系数量为3.0～7.0条,根系平均长度为7.5～9.5cm,根系平均直径不同处理为0.9～1.2mm,不同处理及其与对照之间差异不显著(p>0.05);除"根太阳"生根剂50倍液对山荆子扦插繁殖苗成活率有显著促进作用外,其他处理对扦插繁殖苗成活率,根系数量、长度、直径都没有促进作用或促进作用不明显。     

几种植物生长调节剂对荷兰菊扦插生根的影响

以荷兰菊"粉团"为试材,研究了30、60、90mg/L 3种浓度的2,4-D、吲哚丁酸、萘乙酸(NAA)3种植物生长调节剂处理对荷兰菊扦插枝条的生根时间、生根率、生根数量、根长等指标的影响。结果表明:2,4-D处理对插条生根时间、生根率、生根数量、插条根长指标影响效果总体优于NAA和吲哚丁酸,以2,4-D60mg/L浓度处理的插条生根效果最好;NAA效果最差,但优于清水对照;吲哚丁酸随着处理浓度的升高对插条生根影响效果递增,以90mg/L浓度处理情况下生根状况最好;多重比较分析表明:2,4-D在浓度为60mg/L时对插条根生长影响较显著,较其他激素效果明显。     

容器苗切断胚根的试验研究

容器苗切根育苗试验结果表明:催芽切根苗木的主根和高生长受到一定程度的抑制,但地径、侧根生长发育、须根数量及根系含水均有显著改善,并避免了苗木的畸形,切根容器苗的规格质量明显优于对照,造林成活率也比对照有显著提高。     

根太阳”生根剂在湿加松扦插育苗中的应用效果初报

2005年11月至2006年6月间,在广东省台山市红岭种子园开展了利用“根太阳”生根剂处理湿加松嫩枝的扦插试验。试验结果表明,利用1．25mL／L或1．00mL／L浓度的“根太阳”生根剂可明显缩短湿加松嫩枝生根时间、提高生根率、增加不定根数量和促进生根苗木生长。扦插后133d,经过1．25mL/L“根太阳”生根剂处理的嫩枝,其生根率为86．11％,比对照高10．55个百分点,不定根数量为3．82条,比对照多109．89％。进一步的分析表明,根太阳的促根效果,在扦插后68d就可得到可靠的评价。此外,试验结果也显示,该试验的扦插环境对湿加松嫩枝的生根率、不定根数量和生根苗木生长也有显著影响。     

孔雀草杂交F1代的植株再生

以孔雀草（Tagetes patula）子叶、下胚轴和叶片为外植体,通过器官直接发生途径诱导形成不定芽,探讨植物生长调节剂组合、AgNO3浓度、蔗糖浓度和外植体类型等因素对植株再生的影响,建立了再生体系。结果表明：MS＋6-BA 1.0 · L^- 1＋NAA 0.5 · L^- 1＋AgNO31.0 · L^- 1＋蔗糖40 g·L^-1培养基最适合不定芽的分化和增殖,子叶不定芽分化率达90%以上,平均每外植体分化不定芽数达5.3个。不定芽较适生根培养基为1/2MS＋IAA 0.2 · L^- 1＋NAA 0.1 · L^- 1,生根率达到90%。     

日本樱花高空压条繁殖技术研究

以3号生根粉和萘乙酸2种植物激素为生根剂,对日本樱花高空压条枝进行处理,2种生根剂各设50、100、150、200、300、600kg／L6种浓度,共12个处理,并以清水（CK）作为对照。经统计分析和Duncan新复极差比较,结果表明：3号生根粉和萘乙酸处理都有利于樱花根长和根数量的生长;以200kg／L3号生根粉其根长生长最好,平均根长达到103．81cm;以200kg／L萘乙酸处理,其生根数量最多,平均根数达到86．2根。     

小油桐外植体分化及植株再生影响因素的初步研究

研究发现在MS培养基中添加6-BA 3 mg.L-1+IBA 0.5 mg.L-1的激素对小油桐苗质及外植体分化有明显促进作用。15 d苗龄的小油桐幼苗外植体有较高的分化率。正交实验研究最佳分化激素浓度,发现6-BA+IBA组合对小油桐外植体芽苗诱导效果明显优于6-BA+NAA组合。子叶再生芽诱导最佳培养基为MS+6-BA 3 mg.L-1+IBA 0.5 mg.L-1,最高诱导率为82.9%;下胚轴再生芽诱导最佳培养基为MS+6-BA 2 mg.L-1+IBA 0.2 mg.L-1诱导率为23.8%。在子叶和下胚轴再生培养基中添加1 mg.L-1的AgNO3能促进小油桐植株再生,并抑制褐化产生。小油桐再生苗最佳生根培养基为WPM培养基。     

不同坡位3年生岗梅根系分布及年生长规律

为研究不同坡位及不同土层深度岗梅根系的生长分布特征,于2021年3月—2022年2月,在梅州市平远县热柘镇热柘村3年生的岗梅林中,对不同坡位及不同土层深度的岗梅根数、根长、根粗进行调查与分析。结果表明,岗梅根数在不同坡位间没有显著差异,在不同土层深度间存在显著差异;岗梅根长和根粗在不同坡位间均无显著差异。岗梅根长和根粗的3 a生长量均具有1次明显的高峰增长特点和二次曲线的生长规律。综合结果表明,在赤红壤条件下种植岗梅,其根系分布及根长和根粗均不受坡位影响,岗梅可在山坡任何坡位种植。     

木棉离体再生体系的建立

为给木棉的快速繁殖和转基因研究奠定基础,以木棉下胚轴为外植体,探讨基本培养基种类、植物生长调节剂组合和AgNO3等因素对木棉不定芽诱导和植株再生的影响,建立了下胚轴高效再生体系。结果表明:MS+6-BA 1.5 mg.L-1+NAA 0.1 mg.L-1+KT 0.5 mg.L-1+AgNO31.0 mg.L-1+蔗糖30 g.L-1培养基最适合不定芽的分化和增殖,不定芽分化率达72%,平均每外植体分化不定芽数达3.85个。较适生根培养基为MS+NAA0.5 mg.L-1,生根率达到90%。     

几种植物生长调节剂对黑果腺肋花楸扦插生根的影响

以2,4-D、吲哚丁酸(IBA)、萘乙酸(NAA)3种植物生长调节剂进行黑果腺肋花楸扦插生根影响试验的结果表明,3种植物生长调节剂在优化始生根时间、生根率、生根数量和根长等方面作用显著,其效果均随浓度递增而递减。2,4-D对黑果腺肋花楸扦插生根影响最为显著,其中,2,4-D 20 mg/L处理的促生根效果最佳。     

Armillaria ostoyae in managed coniferous forests in Kastamonu in Turkey

Although several Armillaria species have been reported in Turkey, there is little information about their ecology in Turkish forests. In this study, we investigated five forest stands, approximately 5–74 ha in size, in Kastamonu province in the Black Sea Region of Turkey for the presence of Armillaria species in stumps and logs. The stands were mixed Abies nordmanniana ssp. bornmülleriana and Pinus sylvestris forests managed using a selective cuttings system; the proportion of fir in the total number of stems and stumps ranged from 36 to 98%. Based on sequence analysis of the internal transcribed spacer and intergenic spacer regions of the rDNA, all rhizomorphs sampled from the stumps and logs were of Armillaria ostoyae. The size of the genets was estimated with random amplified microsatellites analysis of the isolates and ranged from single stumps to approximately 450 m². One to seven genets were found in each stand. These results indicate that the genets had arisen from spores and vegetative spread was limited on most sites.     

上海中央公园特大银杏树白蚁防治探讨

通过对上海松江中央公园内65株特大银杏树白蚁为害情况的调查,发现该公园银杏受害率为100%,其中存在活白蚁的银杏占总量的56.9%,采用毒土处理、粉剂疗法、建立白蚁监测点等措施,经过两次灭杀,活白蚁的灭杀率达到92.3%和93.3%,从而使存在活白蚁银杏树的比例从56.9%下降到2.7%,白蚁发生情况明显降低。       

我国食品中农药残留研究进展

随着人们安全健康意识提高,食品中农药残留问题更加受到重视,本文综述了样品预处理研究进展及农药残留快速检测技术研究进展,并简单分析介绍各种方法的优缺点。     

建平半干旱地区石质山地造林技术研究

研究了不同植物在石质山地的造林成活率、土壤化学性质随造林年限的变化和造林措施对土壤化学性质和植物胸径、树高年净生长量的影响。结果表明：不同植物在石质山地的成活率在21%～85%之间,其中白榆和沙打旺的成活率分别为81%和85%,而小叶杨、刺槐、栾树的成活率均在70%左右;植被能明显提高石质山地不同土层的有机质、全N、P2O5含量,但提高程度随土层深度、养分种类和造林年限的不同而不同;在同一土层,生物复合肥料、菌剂和保水剂均显著提高土壤有机质含量（p〈0.01）并显著降低土壤P2O5含量（p〈0.01）;只有保水剂可引起土壤全K含量的明显升高;生物复合肥料、菌剂和保水剂均显著提高白榆、小叶杨、刺槐、栾树树高和胸径的年净生长量,但保水剂的提高程度最高。     

植物DNA甲基化研究进展

植物经常暴露在各种生物和非生物的胁迫之下,这些胁迫会影响植物的生长发育和繁殖并最终导致植物死亡。为了抵御不利的环境条件,植物已经进化出复杂而精细的网络来感知胁迫并激活防御系统。为此,植物激活许多信号转导通路,这些信号转导通路可以改变一些胁迫响应基因的表达,从而引起植物形态、生理和生化的改变以适应逆境。DNA胞嘧啶甲基化是高等真核生物的主要表观遗传机制之一,在维持基因组稳定性和调节基因表达方面起着关键作用。表观遗传变异比遗传变异更为灵活。一旦环境条件发生变化,为了适应新的环境植物都会发生表观遗传的改变。许多研究表明DNA甲基化参与植物的发育和应激反应。基于相关研究对DNA甲基化进行了综述,对植物逆境胁迫有重要意义。     

木材碳封存研究进展

碳封存可以分工业封存和生物封存, 工业封存包括地质封存、海洋封存、矿石碳化以及工业循环利用, 这些方法能快速回收CO₂, 但工艺流程技术复杂, 成本较高。木材碳封存是生物碳封存的一种类型, 树木光合作用吸收的碳主要存贮在木材中。运用木材密度、微密度等检测仪器, 通过确定木材密度变化, 结合其含碳率来计量木材的碳封存过程以及封存过程中碳的分配格局, 同时研究其与环境因子的相关性, 可以为研究森林的碳吸收动态提供便捷的方法和科学的依据。     

Natural regeneration in patch clear-cutting in Picea abies stands in Southern Finland

Abstract

The success of natural regeneration on patch clear-cuts in Norway spruce stands in Southern Finland was examined in terms of stocking and tree height. The experiment was established in mature spruce stands in the submesic Myrtillus (MT) site type. In each of the eight study sites, three plots were treated with clear-cutting and planting, clear-cutting with partial tree retention and planting, and patch clear-cutting without site preparation, respectively. In three of the study sites, one plot with patch clear-cutting and site preparation was established. Each plot was 1 ha, out of which three patches of 40×40 m were clear-cut in the patch treatments. 10–11 years after cutting, the patches had on average 1316 crop trees ha^–1, of which 91% were spruces. Some 27% of the stands were up to the target stocking level (≥1600 ha^?1), and 36% were at least satisfactory (≥1300 ha^?1). Site preparation did not yield greater stocking levels on patches, but that result is ambiguous due to a difference in initial stocking. The average spruce tree height in the patches (0.76 m) was much smaller than in the case of clear-cutting and planting (2.42 m). In conclusion, the patches had been restocked tolerably well with spruce and birch for practical purposes during the 10- to 11-year period, but the regeneration process had been very slow compared to clear-cutting and planting.     

Tree regeneration in patch cutting in Norway spruce stands in northern Finland

The study focused on the success of regeneration on patch cuts in spruce-dominated stands in terms of stocking and tree height. It was based on an experiment in the Kainuu region in northern Finland. The experimental design included 8 stands with 58 clearcut patches of variable size (0.09–0.37?ha), on which either natural regeneration without site preparation or site preparation and planting of Scots pine was applied. A regeneration survey was conducted 13–15 growing seasons after treatments. Patches without site preparation had been restocked quite well from natural seed sources. The average number of trees was about 11,000?ha^?1, of which 1700?ha^?1 crop trees. With site preparation and planting, the stocking levels were also very high, 25,000 and 2100?ha^?1, respectively. One hundred percent of the planted patches and 75% of the naturally regenerated patches had an acceptable density. Restocking was equally good across the range of patch sizes. Tree growth had been somewhat slower in the smallest patches than in the largest ones in the range. Natural regeneration was capable of yielding good regeneration results in most patches, especially when site preparation was applied. Stocking levels and height development were higher yet in the planted patches.     

Changes in micropores in dry wood with elapsed time in the environment

To investigate the changes in microstructures of wood with elapsed time in the environment, CO₂ adsorption onto dry wood was measured at ice-water temperature (273 K) for samples aged from 0.1 years to over 1000 years. The micropore size distribution was obtained using the Horvath-Kawazoe method. Micropores smaller than 0.6 nm in wood decreased in number with elapsed time in the environment, and a negative correlation was found between cumulative pore volume for pores smaller than 0.6 nm and elapsed time in the environment. Cumulative pore volume in the 1000-year sample was almost half of that in the 0.1- year sample. Micropores smaller than 0.6 nm in wood with a few decades or more of elapsed time increased in number after rewetting and drying. Consequently, microstructures of wood with longer time elapsed in the environment were considered to be more stable, because of longer-term thermal motion and possibly more repeated moisture adsorption and desorption and/or temperature variation in the environment.