婺源太白林场吴新华杉苗灾年夺高产

1988年气候异常，杉苗普遍生长不良。婺源县太白林场职工吴新华培育的5亩杉苗，却一枝独秀，在先年亩产5万苗(平均高50厘米以上、根颈0.5厘米)的基础上,又夺得亩产杉苗6万株(平均高40厘米以上、根颈0.35—0．4厘米)的好成绩。     

SH40中间砧苹果苗失水强度对其生理指标及成活的影响

为明确SH40中间砧苹果苗在起苗至假植期间中间砧段率先失水的原因,以1年生红富士/SH40/八棱海棠为材料,测定不同失水强度下苹果苗木各部位的生理指标及其对苗木成活率的影响,以期明确苗木所能承受的极限失水率。结果表明,(1)苗木失水快的部位在根系,根系失水快的部位在于细根;(2)苗木失水对后期的生长量有显著性的影响,苗木失水15%后其幼树总生长量较未失水的苗木显著降低,失水20%后,其树势明显减弱;(3)在各项生理指标中,束缚水/自由水与苗木的成活率呈显著负相关,通径系数为-0.936;其次为自由水,通径系数为0.878,呈显著正相关,苗木水分含量多少对苗木栽植成活率有显著影响。因此起苗至栽植期间,要做好苗木根部保护,尤其防止细根过多失水最为重要。     

营养钵杉苗的培育与造林

杉苗造林，一般采用一年生实生苗的传统造林方法。造林时受季节和气候所限制，成活率低，生长缓慢，生产成本高，出材率低。如果采用营养钵移栽杉苗造林（指一年生裸根杉苗移栽在营养钵中，通过人工培育后而成的造林苗木。），     

用空中压条法繁殖松树

用空中压条法繁殖的植株遗传力较强,可以保持母树的优良性状,同时能提早开花结实,对选种育种具有一定的意义。1972年以来,我们对马尾松、火炬松、湿地松、思茅松空中压条200枝,四季进行均能发根成苗,以春季进行较好,发根成苗率90%。处理枝条时在切口涂吲哚丁酸(150PPM),能促进早发根,加快根的生长速度。具体做法如下: 1.选枝:在生长发育良好的母树上,选择1年生枝条,径粗约1厘米,生势旺盛,皮色光泽,外皮层不厚,内皮层青绿,顶芽健壮,枝体无病虫害及无其他伤害。这类枝条处理后发根快,定植后速生。枝条过嫩,剥皮后     

公路植树de技术措施

一 、植树 苗 木 应 随起 随 栽 ,避 免 使用长 期 假植 苗木 苗 木 失 水 最 快 的 部 位 是 根 系 ,苗木假植后 土壤的保水 性会降低,加 之操作 不细 ,透 风和 通 气 不 良,造 成苗 根 失水和烂根 ,影响成活。 因此应尽量 缩短从起苗到 栽植的时间 ,使起苗与植 树紧密衔接。 尽量做到随 起苗、随栽植。 二 、 长 途运 输 苗 木 时应 做 到 保 湿运输 因 特 殊 原因 需 从 异 地运 来 苗 木 栽植 时 ,一 是 不 能 路 途 太 远 、时 间 过 长 ,二 是 要 做 好 运 输 途 中 的 苗 木 保 湿 、通风 ,以 防 苗 木 失水 和 霉 烂 。具 体 做 法…     

无机盐质量浓度及激素配比对四倍体刺槐组织培养苗生根的影响

在四倍体刺槐试管苗的生根培养阶段,诱导愈伤组织形成根原基,主要取决于6-BA和NAA的质量浓度配比。试验结果表明,在生根培养过程中,单加NAA0．3mg／L,可使组织培养苗发根早,根系发达,须根多,最终能形成完整的健壮植株;当培养基采用低无机盐质量浓度的Ms培养基即l／2MS时,试管苗发根早,且根多而粗壮。     

GGR6号在马尾松芽苗切根育苗中的应用效果

在进行马尾松芽苗切根育苗时使用GGR6号浸根，其移栽育苗成活率高，侧根须根多，发根快。     

营养钵杉苗的培育与造林

杉苗造林,一般采用一年生实生苗的传统造林方法.造林时受季节和气候所限制,成活率低,生长缓慢,生产成本高,出材率低.如果采用营养钵移栽杉苗造林(指一年生裸根杉苗移栽在营养钵中,通过人工培育后而成的造林苗木.),就基本上不受季节和气候的限制,一年四季均可造林,且成活率高达97％,成林时间可缩短3-5年.营养钵移栽杉苗造林在城步苗族自治县云马林场已试验4年,效果较好.     

建兰快速繁殖技术研究

通过对兰花茎尖诱导，原球茎增殖和根、芽分化的培养基筛选及对不同发根时间、不同基质移栽效果试验，结果表明：在ＭＳ培养基上附加ＢＡ３－４ｍｇ／Ｌ和ＮＡＡ１－２ｍｇ／Ｌ诱导茎尖，效果较好，诱导率为６９％；原球茎增殖在改良ＭＳ培养基上附加ＢＡ２－３ｍｇ／Ｌ和ＮＡＡ１－２ｍｇ／Ｌ增殖倍数可达４０倍；筛选出可同时进行原球茎增殖及根、芽分化培养的培养基，用该培养基培养外殖体，每瓶可繁殖完整试管苗２０株，原球茎６０余个；试管苗移栽以发根时间７０天以上为宜，移栽基质以苔藓、红壤土、腐殖土混合物（１：１：１）为佳。     

水分胁迫对油茶容器苗生理特性及成活率的影响

为给油茶容器苗水分的科学管理提供理论依据,在不同失水程度下对油茶容器苗进行了根、茎、叶和基质电阻值以及叶和基质含水量的测定.结果表明:在失水程度0％～30％条件下叶片电阻值呈下降趋势,在失水程度0％～25％的条件下根和茎的电阻值呈下降趋势;当叶片失水程度在30％以上、根和茎在25％以上时电阻值呈上升趋势,尤其在失水程度...     

杉木、观光木混交林群落细根N、P养分现存量动态变化

通过对杉木、观光木混交林和杉木纯林细根的养分现存量动态进行研究 ,结果表明 ,混交林细根N、P养分现存量分别是纯林的 1.3和 1.2倍 ;年归还量分别是纯林的 1.2 3倍和 1.14倍 ,且分别占混交林凋落物N、P养分年归还量的 38.3%和 6 7.4 % ;年分解量分别是纯林的 1.2 6和 1.2 3倍 ,而年累积量分别是纯林的 1.2 3和 1.14倍 ,可见混交林细根具有比纯林更高的养分累积和周转能力。混交林和纯林群落中林下植被细根在群落细根N、P养分循环中占有重要地位 ,而杉木和观光木 <0 .5mm径级细根则是其细根养分循环功能的主体。混交林和纯林杉木活细根N养分现存量动态变化呈单峰型 ,P则呈双峰型 ;死细根N、P养分现存量动态变化均呈倒“S”型。混交林中观光木细根的N、P养分现存量动态变化与杉木的较相似 ,但其活细根P养分现存量动态变化呈单峰型。混交林与纯林中林下植被活细根N、P养分现存量动态变化均呈双峰型 ,而死细根的动态变化则呈单谷型     

Regrowth and dry matter allocation in Quercus robur (L.) seedlings root pruned prior to transplanting

Two-year seedlings of Quercus robur (pedunculateoak) were root-pruned before transplanting in order toevaluate the importance of coarse versus fine roots onregrowth. Root systems were pruned by leaving c. 19,13 or 7 cm root from the root collar. Alternatively,coarse roots (>2 mm in diameter) were removed, leaving only the taproot and the fine roots (<2 mm)attached, or fine roots were removed from coarse rootsand taproot. Growth of shoots and roots after onegrowing season was compared to an unpruned controlunder standard nursery conditions. Seedlings rootpruned to 19, 13 or 7 cm were further tested undercompetition achieved by transplanting into a mixtureof clover and grass. Pruning of the root systemsignificantly reduced regrowth in terms of total plantDW in accordance with the severity of pruning, shootDW being more affected than root DW. Removal of coarseroots depressed final root DW whereas removal of fineroots reduced shoot DW and hence root:shoot ratioincreased. The study suggests that fine and coarseroots have different roles in root:shoot allocation.The competition test increased root:shoot ratioindicating that competition induced seedlings toallocate more of their resources into growth of theroot system.     

Field performance of Quercus petraea seedlings grown under competitive conditions: influence of prior undercutting in the seedbed

Quercus petraea was undercut according to the following procedure: undercutting first year once (July, September, November), twice (July and November), or undercutting in two consecutive years (September of year 1 and either July, September or November of year 2). Undercutting decreased height and dry weight of the seedlings compared to uncut control seedlings. Undercutting in September and July in two consecutive years increased the number of first-order lateral roots. Field performance was evaluated by transplanting under two conditions, (a) competition with a mixture of grasses with no irrigation or fertilisation and (b) standard conditions with fertilisation and irrigation first year and no competition with grass. After two growing seasons under competitive conditions, seedlings undercut in September of year 1 had a significantly higher dry weight compared with that of uncut control seedlings. Numbers of lateral roots and field performance under competitive conditions was related when numbers of lateral roots were small, but not when high. Competitive conditions had limited effect on root growth after one growing season, whereas shoot growth was reduced. After two growing seasons both shoot and root growth were reduced in all treatments compared with standard conditions.     

杉木不同优良品种苗期对比研究

在福建省将乐国有林场对不同种源的6个杉木优良品种进行了苗期对比试验。通过对苗高、地径、高径比及苗木质量分级的分析结果表明,参试杉木优良品种播种品质优良,苗木生长良好,质量高;苗高、地径、高径比在各品种苗木间差异达到极显著或显著水平;广西融水杉木种源种子是苗期表现最为优良的杉木品种。     

不同坡位6年生杉木木荷混交林生物量分布格局分析

对不同坡位6年生杉木木荷混交林林分生长及生物量进行分析研究。研究结果表明,杉木木荷混交林平均胸径、平均树高生长量以及地上部分和地下部分各个器官生物量均体现为下坡位>中坡位>上坡位;杉木各器官生物量表现为树干>树叶>树枝,木荷各器官生物量表现为树干>树枝>树叶;就杉木及木荷不同径级根生物量差异而言,杉木各径级根表现为骨骼根>中根>大根>粗根>小根>细根,木荷则表现为骨骼根>中根>大根>小根>细根。     

Effects of flooding depth on growth,morphology and photosynthesis in <Emphasis Type="Italic">Alnus japonica</Emphasis> species

The present study deals with effects of flooding depth on growth, morphology and photosynthesis in Alnus japonica species thorough one field study and two controlled experiments. In the field study performed in Kushiro Mire, Hokkaido Island, Japan, tree heights and stem diameters decreased with an increase in water depth accompanied with the reduction of soil redox potential. In contrast, the rate of multiple stems per individual tree increased. In the controlled experiments for seedlings flooding suppressed the shoot elongation and biomass increment in roots. However, diameter increment around water levels, epicormic shoot development and adventitious root formation were enhanced in flooded seedlings. The photosynthetic rate and stomatal conductance of flooded seedlings also were lowered with an increase in flooding depth. The recovery of the reduced photosynthetic rate and stomatal conductance occurred simultaneously with the advancement of adventitious root formation in the flooded seedlings. These results indicate the importance of a series of morphological changes occurring on stems around water levels in flood tolerance in A. japonica species.     

Responses of citrus fine roots to localized soil drying: a comparison of seedlings with adult fruiting trees

We studied the responses of citrus (Citrus volkameriana Tan. & Pasq.) roots to 15 weeks of soil drying. A comparison was made between the fine roots of 1-year-old seedling root systems (seedling) and the fine roots of woody laterals of 6-year-old grafted trees (adult). Each seedling and woody lateral root system was established in a pair of vertically separated and independently irrigated soil compartments located in field root chambers excavated adjacent to the trees to which the woody laterals were attached. Root + soil respiration and fine root survival of seedlings and adults were similar for the first 5 weeks. However, eight weeks after termination of irrigation to the upper soil compartments, mortality of fine roots was high in adults but not seedlings. Fine roots of adults exposed to dry soil for 5, 8 and 15 weeks exhibited 2, 26 and 33% mortality, respectively, whereas the corresponding values for fine roots of seedlings were 2, 6 and 8%. Although root + soil respiration rates of adults and seedlings were similar before the soil drying treatment, rates for adults were only 25% of those for seedlings after 15 weeks of soil drying. We conclude that, although fine roots of adults and seedlings are similar in form, they respond differently to soil drying.     

Effects of nickel and copper on growth and mycorrhiza of Scots pine seedlings inoculated with Gremmeniella abietina

Scots pine (Pinus sylvestris) seedlings were planted in soil originating from two localities with different background levels of nickel and copper. In addition, some of the seedlings were exposed to additional nickel (20.5 mg Ni/l of soil) or copper (63.5 mg Cu/l of soil), or a combination of both Ni and Cu, via soil without direct shoot exposure during their second growing period. The seedlings were either irrigated with spring water (pH 6) or got only natural rain during the whole field experiment. All seedlings were inoculated with conidia of a shoot‐pathogen Gremmeniella abietina during their third growing season, and harvested the following spring. Lengths of shoots of different year‐classes were used as growth estimates. In roots, the proportion of fungal (assumedly mycorrhizal) biomass was estimated by measuring ergosterol concentration. Guajacol peroxidase activity was measured. Short roots were classified into two groups according to their condition and the composition of the mycorrhizal community was expressed as a proportion of morphotypes in the roots. The seedlings exposed to additional Ni had higher shoot growth than the seedlings in the other treatments. The mean Ni concentration in the roots of seedlings exposed to additional Ni was 79 p.p.m. and in other seedlings 16 p.p.m. Additional Ni also decreased the frequency of clearly senescent short roots and the proportion of the mycorrhizal morphotype with the thinnest mantle. These results indicate that the Ni exposure levels used in this experiment had some positive effects on the seedlings. The relative fungal biomass was about 6% lower (p = 0.0981) in the fine roots of seedlings treated with additional Cu. The mean Cu concentration in the roots of seedlings exposed to additional Cu was 256 p.p.m. and in other seedlings 29 p.p.m. Peroxidase activity, which was used as a general stress indicator in this study, was not affected by any of the treatments. The shoot growth and the relative biomass of fungi in the fine roots were positively correlated in all seedlings, and this correlation was stronger in seedlings exposed to additional Ni that were not irrigated compared with seedlings not exposed to additional Ni that were irrigated. The frequency of asymptomatic infections of G. abietina was positively correlated with the proportion of senescent short roots in the irrigated seedlings but not in not‐irrigated seedlings. The general condition of seedlings may be an important factor for infection by G. abietina when moisture is high enough for the fungi to infect seedlings by conidia.     

Root cold tolerance of black spruce seedlings: viability tests in relation to survival and regrowth

Root systems of 6-month-old, cold-hardened, container-grown black spruce seedlings (Picea mariana (Mill.) B.S.P.) were exposed to 0, -5, -10, -15, -20, or -22.5 degrees C. Freezing-induced damage to fine roots, coarse roots and the whole root system was assessed by various viability tests including leakage of electrolytes, leakage of phenolic compounds, water loss, root and shoot water potentials, and live root dry mass. To assess the long-term effects of freezing-induced root damage, seedling survival and regrowth were measured. Leakage of both electrolytes and phenolic compounds differed among fine roots, coarse roots, and whole root systems. In coarse roots and the whole root system, but not in fine roots, leakage of electrolytes, leakage of phenolic compounds, water loss, and root and shoot water potentials were correlated with percentage of live root dry mass which, in turn, was highly correlated with seedling survival and regrowth. Compared with live root dry mass, electrolyte and phenolic leakage, water loss, and root and shoot water potentials were less well correlated with seedling survival and regrowth. Among the viability tests, electrolyte leakage of the whole root system correlated most closely with seedling survival and regrowth. Under freezing conditions that destroyed less than 50% of each seedling's root system, about 70% of the seedlings survived and subsequent growth was little affected, whereas under freezing conditions that destroyed 70% of each seedling's root system, only about 30% of the seedlings survived and subsequent growth was reduced compared with that of undamaged plants.     

改进马尾松育苗方法的试验

对马尾松采用控制苗木密度、芽苗截根移栽和接种菌根菌等技术进行育苗试验，结果表明：苗木密度应控制在１５０株／ｍ２，芽苗截根以保留主根长度１／２为宜；采用厚环乳牛肝菌进行人工接种效果较好。