嫁接对橡胶树砧木甲基化水平的影响

选择IAN873、GT1、RRIM600三品种实生树作为接穗,IAN873、GT1、RRIM600播种移栽苗为砧木,用MSAP方法对嫁接前后砧木的甲基化水平进行分析。结果表明,对砧木进行嫁接后发生了甲基化变化,且IAN873接穗引起砧木的甲基化变化大于GT1和RRIM600接穗引起的变化;砧木嫁接后,甲基化变化主要以半甲基化与无甲基化间的相互转换为主,而由半甲基化转化为全甲基化或者由全甲基化转换为半甲基化的很少,全甲基化与无甲基化间的转换居中。     

澳洲坚果品种‘HAES951’为母本的杂交试验

以澳洲坚果品种‘HAES951’为母本,采用9个品种的花粉授粉,获得9个全同胞家系苗木。观测各组合的坐果率、种子横径和杂交F1代苗木的株高、地径及冠幅。结果表明:组合间的坐果率和种子横径均达极显著差异(P0.01);家系内株高、地径、冠幅的变异系数范围在13.67%~30.25%,平均为20.81%。9个全同胞家系间苗木的株高、地径差异不显著,冠幅达显著差异(P0.05)。     

无患子半同胞家系苗期生长表现

本文采用湖南省内30株无患子半同胞家系优树的种子为试验材料,开展家系种子播种育苗,研究各家系1年生苗苗高、地径等主要生长性状的差异.结果表明:家系间苗木的苗高和地径生长差异极显著,表明无患子家系间生长性状的遗传变异丰富,具有较大良种选育潜力.综合苗高和地径性状,初步选择出SM27、SM16、SM05、SM22、SM12...     

秃杉不同家系种子品质及1年生苗木生长变异分析

对90余个秃杉家系种子品质及1年生苗木生长的观测分析表明:秃杉家系种子千粒重平均为1.342 g,变异呈连续的数量性状,近似于对数正态分布曲线;家系的场圃发芽率平均为10.56%,变异呈连续的数量性状,近似于泊松分布曲线;千粒重、场圃发芽率和苗高间呈正相关关系,而千粒重、场圃发芽率与地径相关不密切;1年生苗高和地径在家系间和家系内差异均显著或极显著,而在种源间则苗高差异极显著、地径差异不显著,苗高和地径均大于对照的有19个家系。     

橡胶树优良品种IAN873在云南的适应性

通过对国外橡胶树优良品种IAN873在西双版纳24年适应性观察研究,结果表明:该品种生长快,开割前年均增粗5.65cm,高于对照RRIM600(5.06cm)10.67%;林相整齐,开割时平均茎粗50.5cm,开割率80.2%,分别比对照高2.8cm和10.4%;产胶量中等,1-16割年平均干胶产量1 310kg/hm2,为对照RRIM600(1 969kg/hm2)的66.55%;年平均单株产量为4.0kg,略低于对照RRIM600(4.2kg/年.株)0.2kg;抗辐射寒害能力中等偏下,抗寒力小于GT1,但较RRIM600强;耐割性强,割胶16年后死皮发病率为15.79%,病指14.95,分别比对照(28.79%、27.58)轻13个百分点和12.63。     

铁橡栎不同家系苗期生长差异及其早期选择

以建水县5个铁橡栎种群的22个家系的子代实生苗为研究对象,通过对0.5年生和1.5年生苗木的苗高及地径2个性状的测定,估算其遗传参数,研究其遗传变异规律,采用苗木生长性状指标综合评定与标准差相结合的方法进行优良家系的早期选择。结果表明,(1)铁橡栎子代苗的苗高和地径生长量在家系间,其差异主要是亲本的遗传基础差异所致。其苗高和地径生长均受极强的遗传控制,二者生长趋势高度一致,且具有较好的延续性和稳定性。(2)铁橡栎种子质量的大小影响着其幼苗的生长,种子质量越大的苗木长势越旺盛。(3)苗木生长与母树的生长性状虽无显著的相关关系,但随着苗龄的增大,亲本的优良性状正逐渐得到体现。按综合选择的标准,最终评选出1号、7号、9号、17号、18号、20号、21号和23号8个优良家系,入选率为36.36%。其中尤以17号、9号和18号3个家系生长表现最为突出,其苗高和地径的遗传增益分别达23.70%～33.62%和16.26%～18.24%。     

湖北恩施5个滇楸半同胞家系育苗初报

为发掘利用湖北乡土滇楸资源,本研究对源自恩施地区的5个滇楸半同胞家系开展不同时间播种移栽育苗试验。研究结果表明,3月1日播种4月17日移栽大田的滇楸家系间苗木地径和株高性状存在极显著差异,4月20日播种6月1日移栽大田的滇楸不同家系间苗木地径和株高性状差异均不显著。4月移栽苗木的地径和株高遗传力分别为0.818和0.749,明显高于6月移栽苗木的性状遗传力。     

锦鸡儿属植物种子性状和幼苗生长特征比较研究

以不同种子产地的锦鸡儿属植物柠条锦鸡儿、秦晋锦鸡儿、中间锦鸡儿、小叶锦鸡儿和扁刺锦鸡儿为试材,比较研究了锦鸡儿属植物不同种子产地间的种子性状、种子萌发率及幼苗生长特征。结果表明:不同产地间锦鸡儿属植物的种子性状、萌芽率及幼苗生长特征均存在显著差异。锦鸡儿属植物种子性状受产地影响明显,种子萌发率和幼苗株高的大小顺序均为柠条锦鸡儿秦晋锦鸡儿中间锦鸡儿小叶锦鸡儿扁刺锦鸡儿,幼苗地径的大小顺序为柠条锦鸡儿中间锦鸡儿秦晋锦鸡儿小叶锦鸡儿扁刺锦鸡儿。柠条锦鸡儿的种子萌发率以浑源县的最高,秦晋锦鸡儿以岚县的最高,中间锦鸡儿以岢岚县的最高,小叶锦鸡儿以方山县胡堡村的最高。柠条锦鸡儿幼苗的株高和地径在3个产地间差异不显著,秦晋锦鸡儿在方山县的明显大于临县的,中间锦鸡儿在岢岚县的明显高于方山县的,小叶锦鸡儿为方山县胡堡村的显著高于其它3个地方的。种子千粒重与种子萌发率、苗期生长特征存在显著的相关关系,可作为锦鸡儿属植物苗木出苗和幼苗生长预测的参考指标。     

欧洲白桦早期生长性状变异分析

欧洲白桦(2 a生)13个家系间的苗高性状变异较小,变异范围在22.78%～37.14%之间;家系间地径生长变异较大,而家系内地径生长变异较小,变异范围为20.15%～50.32%.方差分析结果表明:家系问2 a生苗高与地径生长均达差异显著水平.通过2 a连续测定,综合考虑苗高及地径2个性状,初步认为6号、9号、1号、10号及13号等5个家系生长表现良好,且家系内苗木高生长及地径生长变异较小,生长稳定.     

紫薇家系播种品质及苗期生长性状变异

对9个紫薇家系种子的主要播种品质、一年生播种苗的苗期生长性状变异和年生长规律,及其自然越冬存活率进行了研究.结果表明:紫薇家系间的种子播种品质检验指标存在丰富的变异,其中生活力的变异最大.紫薇种子的发芽率与发芽势呈极显著正相关,与生活力显著相关.不同家系内个体间的苗高和地径变异幅度差异较大,家系间的苗高、地径生长量均存在极显著差异.采用Logistic方程能良好地拟合紫薇一年生苗高和地径生长过程.紫薇家系间苗木越冬存活率差异极显著,与生长性状无显著相关.     

云南种植橡胶树品种性状传递遗传分析

以云南植胶区推广种植的橡胶树品种为材料,根据各个品种的试验测定数据和生产中的性状表现,结合亲本特点,分析了橡胶树产量和抗辐射型低温能力两个性状在亲子间的传递关系。结果表明云南推荐品种的51%和自育品种的64%是GT1、PR107、RRIM600和PB86的后裔,GT1和PR107一般配合力高,GT1×PR107特殊配合力高,以在当地规模化种植具有较高重复力的无性系为育种亲本能获得较大遗传增益。要培育更好的地方品种,宜在当地选择符合育种目标的优树经过无性系重复力鉴定后用作育种材料。     

木荷优树子代苗期生长遗传和变异研究

利用设置在福建建瓯、浙江龙泉和淳安3个试验点的96～141个木荷优树自由授粉家系苗期测定材料,以研究和揭示其苗木生长和叶片形态性状的家系遗传变异规律.方差分析结果显示,木荷苗高、地径、叶片数、叶片长和叶片宽等在家系间的遗传差异皆达到极显著水平.性状遗传力估算值显示,苗高和叶片长分别受中等和较强的家系与加性遗传控制,而地径、叶片数和叶片宽等则受弱度至中等的家系和加性遗传控制.试验观测到,与来自较北部和较高海拔地区的家系比较,来自较南部和低海拔地区的家系在各区试点的苗木生长量大、叶片宽大、叶片数多,说明木荷苗木生长和叶片形态的家系效应中还存在明显的产地效应.木荷苗高和地径等不仅立地效应显著,而且存在显著的家系与立地互作效应.基于家系苗期测定结果,以苗高为标准,分别为水热条件较好的中心产区(福建建瓯)、一般产区(浙江龙泉)和水热资源较差的北缘区(浙江淳安)初选出20个速生的优良家系.     

Performance of different rubber tree clones against South American leaf blight (Microcyclus ulei)

This study was aimed to evaluate the behaviour of eighteen clones of Hevea brasiliensis (rubber) against South American leaf blight and to study progress of the disease. The experiment was conducted in Cachoeiro de Itapemirim‐ES, where 18 clones were evaluated. The experimental design was a randomized block with four replicates; each experimental unit consisted of three plants. Evaluations were performed at 15‐day intervals on 30 leaflets per tree. Disease incidence was quantified and infection classified according to the stages of development and type of damage. Leaf blight occurred during the entire experimental period; however, disease intensity varied with the resistance level of the clones and the time of year. Clones FX 3864, RRIM 725, RRIM 711, IAC 300 and IAN 873 exhibited the highest resistance to leaf blight.     

Contrasting strategies to cope with chilling stress among clones of a tropical tree, Hevea brasiliensis

Eight Hevea brasiliensis Muell. Arg. clones (GT1, YUNYAN77-4, IRCA707, IRCA317, PB217, PB260, PR107 and RRIM600) were compared for their tolerance towards chilling stress. Net photosynthesis (Pn), stomatal conductance (Gs), optimal and effective photochemical efficiencies (F(v)/F(m) and ), non-photochemical quenching, cellular lysis and leaf necrosis were measured on trees chilled at 10?°C for 96?h, as well as upon recovery at 28?°C. In addition, ascorbate peroxidase, catalase, dehydroascorbate reductase, glutathione reductase, monodehydroascorbate reductase and superoxide dismutase activities were monitored. Clone RRIM600 appeared to be the most tolerant, because it showed no cellular lysis or leaf necrosis and the best recovery as revealed by Pn, Gs, F(v)/F(m) and . Its ability to sustain chilling stress seemed related in part to the fast closure of stomata, suggesting an 'avoidance strategy' for this clone. IRCA707, GT1 and YUNYAN77-4 were also tolerant to the cold treatment as only a few leaf injuries were observed. However, YUNYAN77-4 showed a particular behaviour with a large stomata opening during the first hour of chilling, some photosynthetic activity after 96?h at 10?°C, but the slowest recovery in Pn. The greatest cell or leaf damage was observed on PB260, IRCA317, PR107 and PB217 clones, thus classified as sensitive to chilling. These clones showed the strongest decrease in Pn, F(v)/F(m) and and the slowest recovery for F(v)/F(m) and , indicating a high sensitivity of photosystem II to cold temperatures. Punctual increases of various enzymatic activities were observed for all clones during chilling kinetics. During recovery, the strongest increases in enzymatic activity were observed for the most tolerant clones, suggesting that efficient reactive oxygen species elimination is a crucial step for determining chilling tolerance in Hevea although the enzymes implicated varied from one tolerant clone to another. This study points out contrasted strategies of the Hevea clones in copping with chilling stress and recovery.     

Evaluation of Brazilian wild Hevea germplasm for cold tolerance:genetic variability in the early mature growth

Hevea brasiliensis is a commercially cultivated species for its natural rubber(NR) latex in South East Asian countries. To meet the ever-increasing demand, NR cultivation has been extended to non-traditional regions due to the limited scope of further expansion in traditional rubbergrowing areas in India. These areas are often confronted with various abiotic stresses, especially high and low temperatures, which cause reduction in plant growth, thereby increasing its uneconomical immaturity period. Eighteen wild Hevea accessions along with two modern clones RRII203 and PB 235 and two check clones RRIM 600 and Haiken 1 were evaluated in the early mature growth phase.The site was at Nagrakata, West Bengal, the sub-Himalayan cold-prone region of India. In Hevea, crop production is governed by two major factors, growth-vigor and production capacity. Growth-vigor is of special importance because the production of rubber is a process linked with the early growth of the plant, which results in early tappability and early economic gains. The genotypes exhibited highly significant clonal differences(P = 0.05) for all the growth traits. Tappability percentage in the seventh year, ranged from 0.33 %(AC 3074, AC 3075, AC 3293) to 89.67 %(RO 2727). The most vigorously growing accession(RO2727) reached tappabile girth early in the seventh year when the girth of plant ranged from 22.38 cm(AC 3293) to53.12 cm(RO 2727). The general mean was 43.32 cm, and the similar growth trend was exhibited by these accessions in the tenth year also. Annual girth increment(cm a-1) over3 years ranged from 1.81 cm(AC 3075) to 6.80 cm(RO2727). The mean winter girth increment(cm a-1) over4 years ranged from 0.13 cm(AC 3075) to 0.96 cm(RO2727) as compared to the check clone RRIM 600(1.11 cm)and Haiken 1(1.10 cm). Wide differences between the phenotypic coefficient of variation(50.29) and genotypic coefficient of variation(24.82) were observed for winter girth increment. Girth in the tenth year recorded the highest heritability(87 %). Girth was significantly correlated with the other growth traits. The top 30 % of the potential accessions showing high growth vigour and early tappability under cold stress were identified. These ecotypes/selections have high potential value for the development of coldtolerant clones for these regions and also in broadening the genetic base of the present-day cultivated rubber.     

大径材杂种落叶松优良家系选择

为选择适宜大径材培育的杂种落叶松优良家系,以40年生全同胞子代测定林31个家系为研究对象,对其生长性状、干形性状、遗传力及遗传增益进行了测定.结果 表明:生长性状单株遗传力整体高于干形性状,树高单株遗传力平均值超过0.5,胸径平均值超过0.4,中央直径平均值超过0.3,材积的平均值超过0.5.胸径和材积的相关系数为0....     

Intra- and inter-clonal tree growth variations of Hevea brasiliensis

We evaluated the effects of planting densities (500, 1,000,1,500 and 2,000 trees·ha-1) on tree growth performance (diameter atbase, diameter at breast height, and clear bole height) of two clones(RRIM 2020 and RRIM 2025) of nine years old plantations of rubber tree(Hevea brasiliensis Muell. Arg) in Malaysia. For the four planting densities of the two clones, basal area and diameter at breast height declined with increasing planting density. Clear bole heights were greatest at 1,500 trees·ha-1 and lowest at 500 trees·ha-1 for the clone RRIM 2020, andat 2,000 trees·ha-1 and 500 trees·ha-1 for clone RRIM 2025. We conclude that the ideal planting density is 2,000 trees·ha-1 for obtaining high volume of wood production and 500 trees·ha-1 for high wood quality.     

油松全同胞家系苗期生长性状遗传变异研究

对来自陕西省陇县八度林场和洛南古城林场两个油松种子园的47个全同胞家系进行苗期试验,结果表明,一年生幼苗苗高、地径、子叶长度、真叶长度、下胚轴高等性状苗期表现在家系间差异显著而在家系内差异不显著;一年生幼苗地径与苗高间存在显著相关关系,真叶长度与地径和苗高均存在显著相关关系,下胚轴高与苗高存极显著相关关系,其余性状间的相关性不显著,二年生幼苗苗高与地径间仍为显著相关关系。二年生与一年生油松幼苗的苗高间存在极显著相关关系,二年生的苗高与一年生地径间也存在显著相关关系,二年生与一年生油松幼苗地径间的相关性则不显著;各性状的家系遗传力均大于单株遗传力。家系遗传力与单株遗传力由大到小的顺序均为苗高>真叶>下胚轴>地径>子叶;初步选取了D8×G3,276×52,C16×B32,B146×K60,265×16,65×305,48×230,B69×B26,44×270,66×245,D11×G8等11个优良家系。     

美洲黑杨与不同种源青杨杂种苗叶片和生长性状多水平变异研究

利用美洲黑杨50号为母本和青杨5个种源(各10个单株)为父本杂交,获得杂种F1代无性系,对此多水平杂交育种体系叶片和生长遗传变异进行了研究.结果表明,父本青杨种源间及种源内单株间均达到极显著差异,F1代无性系的种源间、种源内家系间和家系内无性系间存在不同差异.杂种F1代无性系扦插苗父本种源不同的杂交组合间和组合内家系间成活率差异不显著,1、2、3年生苗的生长性状在不同层次变异水平上差异显著或极显著,表明父本青杨种源间和种源内变异对F1代生长有显著影响,F1代无性系存在丰富的遗传变异,具有选择潜力.杂种F1代叶片形态与苗期生长性状间未发现有较大相关性.