Explore the vast range of titles available.

[目的]通过我国无患子主要分布区的居群样本,研究无患子天然居群的遗传多样性和遗传结构。[方法]采用ISSR分子标记技术,利用12条ISSR引物分析18个天然居群的265株个体样本。[结果]表明无患子遗传多样性水平较高,物种和居群水平上的多态位点百分率（PPB）分别为95.37%和57.82%,Shannon’s信息指数（I）分别为0.256 9和0.199 8,Nei’s遗传多样性指数（H）分别为0.390 9和0.298 0。AMOVA分析表明,18个居群间出现一定程度的遗传分化,且遗传变异主要发生在居群内。UPGMA聚类和Mantel检验结果表明,18个天然居群可分为2大组群,且居群间的地理距离与遗传距离之间不存在显著相关性（r=0.066 7,P=0.541 7〉0.05）。[结论]无患子以自交为主,其天然居群遗传多样性丰富,居群内的遗传多样性高于居群间。研究结果可为无患子育种策略的科学制定和种质资源的有效保护及利用提供理论依据。

S718.81; [目的]研究雷公山国家级自然保护区的棉革菌属外生菌根的分布情况,探索外生菌根与林木互利共生的关系.[方法]采用表型分析和rDNA ITS序列分析等方法,对贵州雷公山国家级自然保护区的常绿阔叶林、落叶阔叶林、暖性针叶林、灌丛4种优势林分的外生菌根进行研究.[结果]表明:基于形态及解剖结构特征分析,从4种优势林分中分离得到7种具有棉革菌属(Tomentella)典型特征(如颜色为棕色)的外生菌根;rDNA ITS区段系统发育分析表明,分离得到的7种外生菌根隶属棉革菌属,并可将其中6种形态型分别鉴定为r badia、T.fuscocinerea、T.atramentaria、T.lapida、rramosissima和T.terrestris.[结论]首次从雷公山国家级自然保护区发现棉革菌属外生菌根真菌6种,为该属外生菌根与优势林分的共生关系及功能研究等提供参考.

[Objective] To explore the ectomycorrhizae types and relationship with forest stands at Leigong Mountain Nature Reserve, and to study the ectomycorrhizae in four preponderant forest stands.[Method] The methods of random sampling and rDNA ITS sequencing were applied in this study.[Result] The results showed that seven types of genus Tomentella were determined by phenotype with brown morphotypes that was similar with genus Tomentella, and the results was verified by rDNA ITS sequencing,. Six of them were identified as T. badia, T. fuscocinerea, T. atramentaria, T. lapida, T. ramosissima and T. terrestris, respectively.[Conclusion] This research is the first report that the genus Tomentella was found at Leigong Mountain Nature Reserve, so the results will benefit for next research at commensalism and function with four preponderant forest stands at Leigong Mountain Nature Reserve. [目的]研究雷公山国家级自然保护区的棉革菌属外生菌根的分布情况，探索外生菌根与林木互利共生的关系。[方法]采用表型分析和rDNA ITS序列分析等方法，对贵州雷公山国家级自然保护区的常绿阔叶林、落叶阔叶林、暖性针叶林、灌丛4种优势林分的外生菌根进行研究。[结果]表明

[Objective]To reveal the genetic diversity and genetic structure in natural populations of Sapindus mukorossi. [Method]The genetic diversity and genetic structure of 265 S. mukorossi individuals sampled from 18 natural populations distributed in China were examined using fifteen inter-simple sequence repeat (ISSR) markers primers. [Result]The percentages of polymorphic bands (PPB) at the species and population level were 95.37% and 57.82%, respectively. The Shannon's indexes (I) of phenotypic diversity at the species and population level were 0.256 9 and 0.199 8, respectively, and Nei's genetic diversities (H) at the species and population level were 0.390 9 and 0.298 0, respectively. These results indicated that S. mukorossi contains relatively high levels of genetic diversity. There was genetic differentiation among the 18 populations to a certain level (GST: 0.233 7; FST: 22.22%; AMOVA genetic differentiation: 24.74%), and most of the genetic differentiation occurred within populations. The UPGMA clusterin

对我国无患子分布区7个产地的种实形态性状及种仁含油率进行取样测定。方差分析结果表明，种实各性状在产地内单株间的变异程度不同，但多数性状在多数产地内均存在丰富的变异，在产地内进行单株选择是可行的。在不同产地间，无患子种实各性状均存在显著差异，河南西峡产地果实和种子较大，与其它产地间差异显著。无患子种仁含油率产地间变异系数最小，与地理气候因子间不存在明显的相关性，而种子质量、种子出仁率在不同产地间变异系数相对较大，且与种实大小显著正相关，可以通过选择较大的果实、种子来提高产油量。聚类及相关性分析表明，在一定程度上，无患子种实大小和种子出仁率有从低纬度产地向高纬度产地变大的变异趋势，因此无患子高产油单株的选择应重点在较高纬度产地果实、种子较大的个体中进行。

The morphological characters of fruit, seed and kernel oil content of Sapindus mukorossi in 7 producing areas were investigated. The results of variance analysis showed that the degrees of characters variation were different among individuals in these producing areas, but most chara ters had wide range of variation in most producing areas, so individual selection was effective. However, all characters had significant differences among producing areas. The producing area of Xixia County of He'nan Province had obvious differentiation from the others, and with bigger fruits and seeds. The oil content of kernel, with the smallest variation coefficient, had no obvious correlation with geographical factors of different producing areas. In contrast, the seed weight and kernel rate had larger variation coefficient among different producing areas, and they had significant positive correlations with the size of fruits and seeds. So it is feasible to raise oil content by selecting big fruits and seeds. Cluster and corre

以我国亚热带落叶阔叶优势树种毛红椿的1年生幼苗为试验材料,设置4个水分胁迫处理,模拟研究不同水分胁迫强度下毛红椿幼苗生长和生物量分配规律.结果表明：水分胁迫对毛红椿幼苗根系生长的限制作用明显大于对苗高生长的限制作用,对地径生长限制作用不明显;随着水分胁迫程度增加,根质量比表现出先增大后减小的趋势;叶质量比在处理初期和中期增大,在处理后期和末期降低;在整个处理阶段,茎质量比始终保持增加趋势;根系平均直径在处理中期和后期逐渐减小,处理末期则有所上升;细根/总根长比值则在处理中期和后期逐渐增大,处理末期则有所降低;不同水分胁迫程度导致根尖数量差异显著.在整个处理阶段,水分首先保证苗高和叶片生长,根系生长受到限制;随着水分胁迫程度增加,通过落叶和根系二次生长来保障根系的水分需求和提高水分吸收效率,以此来缓解水分胁迫对生存的胁迫.

对无患子果实生长发育动态及果肉内含物含量变化进行研究，结果表明．无患子果实纵径、横径、侧径、鲜质量等性状发育进程呈现明显的S型生长曲线特征；以果实生长发育时期为横轴（＊），分别以果实纵径、横径、侧径、鲜质量的均值为纵轴（Y），构建的果实生长发育数学模型表明，无患子果实生长各性状与果实发育时期高度相关，数学模型可以正确地反映无患子果实生长发育动态变化规律。对无患子果实脱落规律、果肉含水量、可溶性糖含量、皂苷含量变化规律等综合分析表明，10月下旬，无患子果实发育成熟，生长性状趋于稳定，果肉含水量和可溶性糖含量从峰值下降至相对较低水平，而果肉皂苷含量相对较高，因此提出该时期为无患子果实采摘的适宜时期。

The dynamic changes of fruit development and pulp inclusion of Sapindus mukorossi were studied. The results showed that the development process of fruit vertical diameter, transverse diameter, side diameter and fresh weight presented an obvious Sigmoid growth curve. The mathematical models of fruit growth and development were built by using development period as X-axis, and using respective mean of fruit traits as Y-axis. Meanwhile, the models were proved available to reflect the change rule, because the fruit growth traits highly correlated with development periods. The change rules of fruit drop, pulp water content, pulp soluble sugar content and pulp saponin content were analyzed comprehensively. The result indicated that the fruits matured and the growth traits tended towards stability in later October, and the pulp water content and soluble sugar content decreased from peak to relatively low levels. However, the pulp saponin content was relatively high at the same time. So the suitable period for fruit h

Toona ciliata var. pubescens is a native and widespread dominant deciduous broad-leaf tree in the subtropical region of China. An experiment was conducted to investigate the effect of water stress on the growth, biomass partition and root characteristic index of 1-year-old T. ciliata var. pubescens seedlings. The seedlings grew under well-watered and water stressed conditions which were imposed by controlling the water supply. The results showed that the water stress had a negative significant effect on the root growth, but no effect on the growth of ground diameter was found. The root mass ratio increased in the beginning, and then decreased. The leaf mass ratio increased at the early and medium water stress period, and decreased at later and terminal water stress period. The shoot mass ratio increased from beginning to end. The average root diameter decreased gradually from the medium to the later water stress period, and then increased at terminal water stress period. However, the ratio of fine root to tot