Pt茵剂对尾叶桉苗木抗旱性的影响

对尾叶按苗木采用Pt菌剂(Pisolithus tinctorius)和水分胁迫处理,研究不同处理对该苗木生长及营养物质积累方面抗旱性的影响.结果表明:接种茵荆后水分胁迫条件比常规供水更利于苗高生长.无论常规供水还是水分胁迫条件下,接种茵剂10 g地径增长量都最大,高Pt茵剂施用量对地径增长量有一定的抑制作用.茵剂处理能提高苗木生长质量.常规条件下,茵剂5 g处理苗木质量最高；胁迫条件下,茵剂10 g处理苗木质量最高,而对总体抗旱性而言,菌荆15 g处理效果最好.     

稳态营养与Pt菌根化在湿地松育苗中的应用

在苗圃地培育湿地松苗木 ,分别进行 4种处理 :①稳态营养 Pt菌剂 ;②不施肥 Pt菌剂 ;③稳态营养 松林土 ;④常规施肥 松林土。生长季末测定苗木的高度和地径。测定各小区标准木的叶、茎、根鲜重及干重 ,侧根条数和总长。按“十分法”目测吸收根外生菌根感染率。观测结果表明 ,湿地松苗木形成外生菌根的能力较强 ,无论是人工接种还是天然感染 ,菌根感染率均超过 85 % ,其中稳态营养下 ,人工接种Pt菌剂感染率最高 ,可达94 8%。稳态营养人工接种Pt菌剂处理的苗木生长最佳 ;稳态营养下松林土处理的苗木其次 ;人工接种Pt菌剂但不施肥处理的苗木再次 ;常规施肥 松林土处理最差。如稳态营养人工接种Pt菌剂处理与人工接种Pt菌剂但不施肥处理相比较 ,苗木的株高、地径分别提高 2 0 5 %、14 0 % ;侧根条数及总长分别提高 2 5 6 %、4 0 9% ;叶、茎、根、整株鲜重分别提高 34 6 %、4 3 7%、38 8%、37 0 % ;各部分干重分别提高 2 5 7%、38 6 %、4 2 4 %、32 7%。稳态营养人工接种Pt菌剂处理与常规施肥松林土处理相比较 ,各项指标的差异更加明显。充分体现了稳态营养与Pt菌根化的综合效应 ,同时说明稳态营养条件下 ,靠松林土感染真菌形成菌根也能获得较好的生长结果。但是 ,仅靠人工接种优良菌剂 ,不科学     

不同施肥方法对台湾相思苗木生长的影响

对台湾相思10个月苗木进行不同施肥方法和水分胁迫试验,结果表明:施肥对苗木高、径生长有明显的促进作用,其中平均施肥最有利于苗木的生长;在常规浇水的条件下3种施肥方法下苗木的总生物量顺序为:指数施肥平均施肥直线施肥ck(不施肥);水分胁迫有利于苗木根生物量的积累,提高了苗木的抗旱性。     

不同处理对大叶相思幼苗抗逆性及造林效果的研究

为了提高大叶相思幼苗在干热河谷地区造林的成活率,2008年在元江通过对其幼苗分别进行不同剂量的Pt菌剂、干旱胁迫和Pt菌剂+干旱胁迫处理,测定出圃幼苗的苗高、地径、高径比、生物量等形态指标和叶绿素、可溶性糖含量及SOD酶活性等生理指标,并比较其抗逆性,同时对不同培育措施出圃幼苗造林6个月时的成活率和生长状况进行测定与比较。结果表明:随着Pt菌剂的使用量增加,大叶相思出圃苗木的高径比和地上部分和地下部分生物量的比值逐渐降低,SOD酶活性和可溶性糖含量逐渐增加,因而出圃幼苗的抗逆性增强;干旱胁迫和Pt菌剂的作用效果可以叠加。Pt菌剂10 g+干旱胁迫大叶相思的处理效果最佳,成活率最高。     

Pt菌剂对高阿丁枫苗木生长的影响

进行高阿丁枫接种Pt菌剂的育苗效果试验。结果表明:Pt菌剂对高阿丁枫苗木的生长有明显的促进作用。经Pt菌剂处理后高阿丁枫苗木的苗高、地径、侧根数、主根长、地上部分鲜重、地下部分鲜重、全重及一级侧根长分别较不经Pt菌剂处理的对照提高了23.1%、8.7%、23.1%、21.0%、25%、33.3%、26.7%、49.2%。且苗木的径高比不失衡。     

Pt、ABT处理对马尖相思苗木生长的影响

通过接种Pt菌剂及施用3号ABT生根粉,进行马尖相思播种育苗试验。结果表明:Pt菌剂和3号ABT生根粉都对马尖相思苗木生长及生物量有明显的促进作用。用Pt菌剂处理后苗高、地径、侧根数、主根长、地上部分质量、地下部分质量、全质量及一级侧根长分别较对照有提高。用3号ABT生根粉处理后苗高、地径、侧根数、主根长、地上部分质量、地下部分质量、全质量及一级侧根长分别较对照有提高。     

不同水分下菌根育苗对大叶相思苗木造林效果的影响分析

为了解不同水分下菌根育苗对大叶相思苗木的影响,本试验以大叶相思为研究对象进行试验,研究干旱胁迫和Pt菌剂育苗对干热河谷地区造林效果的影响。研究结果发现:干旱胁迫和Pt菌剂具有叠加作用,能够极大地提高苗木的抗逆性和造林存活率,其中以Pt菌剂15g+干旱胁迫的造林效果最佳,从而为大叶相思苗木造林提供重要的理论依据。     

育苗期不同处理对尾叶桉U6无性系苗木质量及造林效果的影响

在云南的元江干热河谷,进行了尾叶桉U6无性系扦插苗育苗期的施用不同剂量Pt菌剂及干旱胁迫处理,提高苗木质量及植苗造林效果的研究。结果表明,以每株苗木用Pt菌剂15g+干旱胁迫处理的效果最佳,干旱胁迫反应能力的提高和施用Pt菌剂的增效作用可以叠加。其有助于提高尾叶桉U6无性系扦插苗出圃苗木的质量,使其植苗造林6个月时的造林成活率达93.33%。通过相关性分析,筛选出反映尾叶桉U6无性系扦插苗木主要质量指标的因子是出圃苗木的主根长、苗高、地径、高径比和总生物量,并对尾叶桉U6无性系扦插苗主要质量指标与其造林成活率的相关性进行了分析,建立了相关的回归方程。     

不同水分胁迫下罗甸小米核桃生长特性研究

以罗甸小米核桃苗木为试验材料,采用称取质量控制土壤含水量的方法,设置对照(CK)、轻度水分胁迫(W1)、中度水分胁迫(W2)和重度水分胁迫(W3)4个不同处理,研究罗甸小米核桃幼苗的生长特性。结果表明:水分胁迫下,罗甸小米核桃的生长受到抑制,苗高、地径、叶面积、生物量增长量都呈现出减少的趋势,并且随着水分胁迫强度和胁迫周期的增加而下降。     

马尾松芽苗移栽根菌根化育苗试验

在非松林砍伐迹地上或贫瘠的地区应用芽苗移栽截根接种Pt菌剂能有效促进苗木的生长，苗高提高了6．25％－21．2％，地径提高了6．67％－20％、侧根总数提高了100％－110％、菌根感染率提高了18．8％－110％。在松林砍伐迹地上进行的试验结果表明，Pt菌剂与乡土菌根菌对Pt菌有一定的换制作用，接种苗木的菌根感染率有所下降，对苗木的生长作用不明显。截根接种Pt菌剂及截根未接种的苗木冬季的苗高生长情况可以看出，该技术能有效促进苗木的木质化。     

Short-day treatment enhances root egress of summer-planted Picea abies seedlings under dry conditions

Abstract

Second year Norway spruce [Picea abies (L.) Karst.] container seedlings, short-day (SD) treated for 3 weeks in July, were exposed together with untreated control seedlings (Co) to three different drought treatments for 5 weeks after planting in early August. The treatments were: (1) regular watering (0 week drought); (2) 2 weeks of drought and 3 weeks of watering; and (3) no watering (5 week drought). No difference was found in the vigour and shoot xylem water potential between the SD-treated and the Co seedlings after the drought treatments. The root growth decreased less for the SD seedlings than for the Co seedlings along with the increase in the length of the drought period.     

水分胁迫下外生菌根对马尾松幼苗养分吸收的影响

利用接种褐环乳牛肝菌、鸡油菌、彩色豆马勃、土生空团菌的马尾松苗,在温室采用盆栽方法,研究水分胁迫下,不同菌根化苗对养分的吸收情况.结果表明:在水分胁迫下,外生菌根能显著提高马尾松幼苗对N、P、K的吸收.随胁迫加剧,菌根化苗N、P含量和磷酸酶活性均呈先增后降趋势,在中度胁迫时达最大,其中,接种褐环乳牛肝菌l的苗对N、P吸收效果最好,分别比对照增加56.65％和44.32％;接种彩色豆马勃和褐环乳牛肝菌1的马尾松苗的K含量随胁迫的加剧先增后降,在轻度胁迫时达最大,分别比对照增加221.99％和200.00％.N和K主要分布在叶中,而P在根、茎、叶中分布较均匀,菌根的形成有利于马尾松幼苗N、K的上行运输.在轻度和中度胁迫下,接种褐环乳牛肝菌1对提高马尾松苗N、P、K的吸收和含量效果最好,同时也促进了马毛松幼苗生长和抗旱能力的增强.     

干旱胁迫对榆树幼苗生物量分配的影响

干旱是主要的环境胁迫因子之一,严重影响植物的分布与生长发育。通过选取辽宁阜新章古台沙地1年生榆树幼苗为材料,采用盆栽控水方法,设置田间持水量80%、60%、40%和20%等4个水分处理梯度,研究干旱胁迫对榆树幼苗株高、基径及叶片、茎和根系生物量分配的影响。结果表明:随着干旱胁迫程度增加,幼苗茎和根系的生物量逐渐降低;但轻度干旱胁迫增加了株高和基径的生长,提高了叶片生物量,以抵御干旱胁迫的影响。中度干旱胁迫下,增加了根系生物量分配的比例,从而更利于获取水分资源适应干旱环境;重度干旱胁迫下幼苗无法存活。在科尔沁沙地,栽植榆树幼苗保证存活生长的最低田间持水量为40%。     

虎榛子几种菌根苗抗旱机制的研究

选用6个外生菌根菌株为接种体,分别对2个月龄虎榛子实生苗进行接种,培养4个月菌根感染率均超过40.8%.测定各处理苗木生物量、膜透性、SOD活性、MDA含量、叶绿素含量等指标,结果表明:彩色豆马勃、土生空团菌是以提高植物组织水势、SOD活性、降低MDA含量、减轻膜伤害程度、增加根冠比等机制来增强苗木的抗旱性,从而推迟苗木的萎蔫时间与延长干旱临界致死时间;厚环粘盖牛肝菌及点柄粘盖牛肝菌是通过提高苗木SOD活性和脯氨酸含量、降低MDA含量等机制来提高苗木的抗旱性;而卷边桩菇则是通过促进苗木的生长、增强苗木的生长势、降低苗木膜伤害程度、提高SOD活性和脯氨酸浓度、降低MDA含量等多种机制提高苗木的抗旱性.     

紫穗槐幼苗在不同干旱胁迫下生长特性的研究

干旱对紫稳槐幼苗的茎高、地径、叶片外部形态、生长状态等生态指标的影响的结果表明：干旱胁迫对植株的生长有明显的抑制作用。随着干旱胁迫时问的延长、胁迫强度的加剧,其株高和地径减小,复叶叶柄总长度、小叶数量,叶面积也逐渐减小;在长时间干旱胁迫下紫穗槐采用脱落下部枝叶的方式,确保个体生存以增强抗旱性。     

水松幼苗的水分和铜胁迫试验

应用盆栽试验方法,比较研究了水松幼苗在不同水分和铜胁迫条件下的生长表现。结果表明:①在渍水(Wa)、隔天渍水(Wb)及3天浇水1次(Wc)和7天浇水1次(Wd)等4种水分胁迫条件下,Wc处理组幼苗生长表现最好;Wa和Wb处理组次之,Wd处理组幼苗在第7 d就出现萎焉,至第10天时全部死亡。②在Cu2+50(Cu50)、100(Cu100)、200(Cu200)、500mg·L-1(Cu500)等4种铜胁迫条件下,水松裸根苗在第10天时全部死亡;水松土培苗也出现不同程度的死亡和生长受抑现象,随着铜胁迫时间的延长,其成活率和生长量与对照组(Cu0)的差异增大;至90 d时,Cu500处理组的苗木存活率只有22.2%,其幼苗高增长量仅为对照组的38.2%。     

Growth and biomass production in Azadirachta indica seedlings in response to nutrients (N and P) and moisture stress

Production of quality seedlings is an important aspect of successful tree planting. No information is available on the effect of nutrients and water on the growth and development of the seedlings of neem (Azadirachta indica A. Juss), an important component of many tropical agroforestry systems. In an experiment in central India, the growth and nutrient-use efficiency of neem seedlings grown at various levels of light, nutrients (N and P), and water stress were determined. Seedlings were given light (diffused and complete) and nutrient (N and P) treatments comprising either high N-high P, high N-low P, low N-high P, or low N-low P. Seedlings grown in complete light (800 mol/m²/s) had four times more biomass than those grown in diffused light (200 mol/m²/s). Significant increase in seedling biomass was observed with nitrogen application, while phosphorus had no effect on biomass. Leaves contributed maximum biomass, followed by roots and stem. Nutrient use efficiency decreased with an increase in the supply of nutrients. In another experiment, containerized and bare-root seedlings were subjected to five watering treatments, viz., watering twice a week, watering weekly, watering every alternate week, watering every third week, and natural precipitation. Plant moisture stress affected both growth and survival of neem seedlings. Only 50 per cent of seedlings survived in severe drought treatment (no. 4) whereas 90 to 95 per cent seedlings showed growth in all other treatments. Plant moisture stress in severe drought treatment averaged –21 bar while in other treatments it ranged from –9 to –12 bar. Shoot-root ratio was high in bare-root seedlings as compared to containerized seedlings. Containerized seedlings had shown better endurance against drought than the bare-root seedlings. The results suggest that neem seedlings adjust their nutrient use efficiency and can be grown even under limited available resources. It is also inferred that the species can tolerate soil resource depletion caused by competitor species.This revised version was published online in November 2005 with corrections to the Cover Date.     

Growth, nutrition and response to water stress of Pinus pinaster inoculated with ten dikaryotic strains of Pisolithus sp

Reconstituted dikaryons of Pisolithus sp. (Pers.) Coker & Couch from South Africa influenced growth parameters (shoot length, shoot/root ratio and leaf area), nutrition and physiological indicators (transpiration rate, stomatal conductance and xylem water potential) of maritime pine (Pinus pinaster Ait.) seedlings during drought and recovery from drought. Seedlings colonized with certain dikaryons were more sensitive to water stress and showed less mycorrhiza formation under water stress than seedlings colonized with other dikaryons. Control (uninoculated) seedlings were significantly smaller than those inoculated with dikaryons. Transpiration rate, stomatal conductance and xylem water potential varied among mycorrhizal treatments during the water stress and recovery periods. After rewatering, the controls and seedlings inoculated with dikaryon 34 x 20 had a weaker recovery in transpiration rate, stomatal conductance and xylem water potential than the other treatments and appeared to have experienced damage due to the water stress. Concentrations of various elements differed in the shoots of Pinus pinaster colonized by the various dikaryons. It is suggested that breeding of ectomycorrhizal fungi could constitute a new tool for improving reforestation success in arid and semi-arid zones.