69个东北杏(Prunus mandshurica)无性系果实表型多样性及优良无性系筛选

【目的】深入探寻东北杏种质资源遗传多样性,筛选关键综合评价指标,提升育种效率,发掘优良东北杏无性系并高效利用。【方法】采用多样性分析、聚类分析、相关性分析和主成分分析,对69个东北杏无性系的45个果实表型性状(23个质量性状和22个数量性状)进行研究。【结果】41个表型性状变异系数大于0.1,数量性状的平均Shannon-wiener多样性指数(1.91)高于质量性状(0.62),数量性状的多样性较质量性状更丰富。聚类分析将69个东北杏无性系分为3类,A类适用于薄壳、出仁率高的品种类群;B类可用于选育高产、大仁型品种,属优良仁用杏品种类群;C类可作为高出核率和出仁率的重要育种材料。果肉薄、果小的无性系出核率更高;核壳薄、单核质量小的无性系出仁率更高;单核质量大的无性系产核量更高。5个主成分的累计贡献率达84.42%,能够反映22个数量性状的基本信息。结合相关性分析和主成分分析,22个数量性状可简化为果肉厚度、果纵径、单果质量、单核质量、单仁质量、出核率、出仁率、产核量共8个关键评价指标,筛选出10个果实经济性状表现优异的无性系。【结论】东北杏无性系的果实性状表现出丰富变异,经多指标综合评价筛选出的803、777、783、720、721、725、719、711、731和784号无性系可用于东北杏良种选育及开发利用。

Selection of Suitable Area and Analysis of Adaptability Difference of Prunus humilis

This paper delves into and assesses the differences in biological traits and fruit nutritional composition of 3 varieties of Prunus humilis introduced from 2 different regions.Results showed that(i)the contents of protein,total sugar,and calcium of No.5 variety were higher those of the other 2 varieties,which was recognized as the most suitable variety for fresh fruit;(ii)the comparison of leaf areas index and fruit shape index of 3 varieties shows that the fruit shape index and individual fruit weight of the introduced varieties were higher than those of the control,the diameter of individual fruit of the introduced varieties higher than that of the control indicated that they had a higher fruit hardness,more dry matter accumulation and better fruit quality,and that the introduction region was more suitable for scale-up of P.humilis;(iii)there was a positive correlation with the number of fruiting branches and there was a significant negative correlation with individual fruit weight,while the leaf area had a significant negative correlation with the number of fruiting branches.The introduced varieties can develop normally in the 2 testing areas,notably,No.5 variety performed better than No.4 and No.6.Improving management is the prerequisite for maintaining proper number of fruiting branches and high yield.

Supervised Learning Method: Critical Analysis and Updating of Cubing Rate Formulas for Determining Bark Masses of Prunus africana (Hook. f.) Kalkman (Rosaceae) in Cameroon

The stem barks of Prunus africana are used in the treatment of the benign prostate. Cameroon is one of the important exporters of the barks. Despite the important measures adopted in Cameroon for sustaining its harvesting, some many chalenges still remain. The objective of this work is to refine the forest management parameters in relation to P. africana in the regions of Adamaoua and the South-West by developing a volume rate which makes it possible to estimate the production for a new stem. The work took place in two phases: in the South-West in 2010 and in Adamaoua in 2011. Data collection used the semi-direct method, while the cubing equation was deduced by the multiple linear regression method. Two models for volume estimation and three models for mass prediction were developed. The predictive parameters retained are diameter, height of the bole and thickness of the bark. Results show that the average mass of the dry bark for a given P. africana tree species is 27.55 ± 14.44 kg and this varies according to the site. The strong adjusted coefficient of determination (adjusted R2) observed illustrates the reliability of the proposed models. These models provide a reliable tool that can be adopted as a standard in Cameroon for P. africana.

Molecular phylogeny and inflorescence evolution of Prunus(Rosaceae)based on RAD-seq and genome skimming analyses

Prunus is an economically important genus widely distributed in the temperate Northern Hemisphere.Previous studies on the genus using a variety of loci yielded conflicting phylogenetic hypotheses.Here,we generated nuclear reduced representation sequencing data and plastid genomes for 36 Prunus individuals and two outgroups.Both nuclear and plastome data recovered a well-resolved phylogeny.The species were divided into three main clades corresponding to their inflorescence types,-the racemose group,the solitary-flower group and the corymbose group-with the latter two sister to one another.Prunus was inferred to have diversified initially in the Late Cretaceous around 67.32 million years ago.The diversification of the three major clades began between the Paleocene and Miocene,suggesting that paleoclimatic events were an important driving force for Prunus diversification.Ancestral state reconstructions revealed that the most recent common ancestor of Prunus had racemose inflorescences,and the solitary-flower and corymb inflorescence types were derived by reduction of flower number and suppression of the rachis,respectively.We also tested the hybrid origin hypothesis of the racemose group proposed in previous studies.Prunus has undergone extensive hybridization events,although it is difficult to identify conclusively specific instances of hybridization when using SNP data,especially deep in the phylogeny.Our study provides well-resolved nuclear and plastid phylogenies of Prunus,reveals substantial cytonuclear discord at shallow scales,and sheds new light on inflorescence evolution in this economically important lineage.

Genome of tetraploid sour cherry (Prunus cerasus L.) ‘Montmorency’ identifies three distinct ancestral Prunus genomes

Sour cherry(Prunus cerasus L.)is a valuable fruit crop in the Rosaceae family and a hybrid between progenitors closely related to extant Prunus fruticosa(ground cherry)and Prunus avium(sweet cherry).Here we report a chromosome-scale genome assembly for sour cherry cultivar Montmorency,the predominant cultivar grown in the USA.We also generated a draft assembly of P.fruticosa to use alongside a published P.avium sequence for syntelog-based subgenome assignments for‘Montmorency’and provide compelling evidence P.fruticosa is also an allotetraploid.Using hierarchal k-mer clustering and phylogenomics,we show‘Montmorency’is trigenomic,containing two distinct subgenomes inherited from a P.fruticosa-like ancestor(A and A’)and two copies of the same subgenome inherited from a P.avium-like ancestor(BB).The genome composition of‘Montmorency’is AA’BB and little-to-no recombination has occurred between progenitor subgenomes(A/A’and B).In Prunus,two known classes of genes are important to breeding strategies:the self-incompatibility loci(S-alleles),which determine compatible crosses,successful fertilization,and fruit set,and the Dormancy Associated MADS-box genes(DAMs),which strongly affect dormancy transitions and flowering time.The S-alleles and DAMs in‘Montmorency’and P.fruticosa were manually annotated and support subgenome assignments.Lastly,the hybridization event‘Montmorency’is descended from was estimated to have occurred less than 1.61 million years ago,making sour cherry a relatively recent allotetraploid.The‘Montmorency’genome highlights the evolutionary complexity of the genus Prunus and will inform future breeding strategies for sour cherry,comparative genomics in the Rosaceae,and questions regarding neopolyploidy.

Chromosome-scale genome assembly of Prunus pusilliflora provides novel insights into genome evolution, disease resistance, and dormancy release in Cerasus L.

Prunus pusilliflora is a wild cherry germplasm resource distributed mainly in Southwest China.Despite its ornamental and economic value,a high-quality assembled P.pusilliflora genome is unavailable,hindering our understanding of its genetic background,population diversity,and evolutionary processes.Here,we de novo assembled a chromosome-scale P.pusilliflora genome using Oxford Nanopore,Illumina,and chromosome conformation capture sequencing.The assembled genome size was 309.62 Mb,with 76 scaffolds anchored to eight pseudochromosomes.We predicted 33035 protein-coding genes,functionally annotated 98.27%of them,and identified repetitive sequences covering 49.08%of the genome.We found that P.pusilliflora is closely related to Prunus serrulata and Prunus yedoensis,having diverged from them∼41.8 million years ago.A comparative genomic analysis revealed that P.pusilliflora has 643 expanded and 1128 contracted gene families.Furthermore,we found that P.pusilliflora is more resistant to Colletotrichum viniferum,Phytophthora capsici,and Pseudomonas syringae pv.tomato(Pst)DC3000 infections than cultivated Prunus avium.P.pusilliflora also has considerably more nucleotide-binding site-type resistance gene analogs than P.avium,which explains its stronger disease resistance.The cytochrome P450 and WRKY families of 263 and 61 proteins were divided into 42 and 8 subfamilies respectively in P.pusilliflora.Furthermore,81 MADS-box genes were identified in P.pusilliflora,accompanying expansions of the SVP and AGL15 subfamilies and loss of the TM3 subfamily.Our assembly of a high-quality P.pusilliflora genome will be valuable for further research on cherries and molecular breeding.

Post Debarking Response of Prunus africana (Hook. F) Kalkman (Rosaceae) Trees at Two Exploitation Sites in North Kivu (Eastern Democratic Republic of Congo)

Prunus africana is a species of great economic, medicinal and ecological importance. Due to its multiple uses, unsustainable exploitation methods and low regeneration capacity in tropical rainforests, this species is threatened with extinction. Present and exploited in the eastern part of DR Congo, knowledge of the dynamics of post-bark regeneration of Prunus africana remains fragmentary and poorly known. In North Kivu province, this species thrives in both afromontane forest and lowland tropical rainforest habitats. In order to contribute to the rational and sustainable exploitation of Prunus africana in this province, this paper was carried out with the objective of contributing to the knowledge of the dynamics of the regeneration of post-harvest bark of Prunus africana in two exploitation sites (low and high altitude). To achieve this objective, the inventory was conducted on 16 plots of 25 hectares each, with 8 plots per site. Dendrometric parameters (diameter at breast height (DBH), total tree height) and tree growth and regeneration parameters, i.e., stem bark thickness of the unharvested and harvested portions of the trees (bark reconstitution) were measured. A total of 716 barked stems of Prunus africana in 2016 in 25 hectares constituted the study sample. Results show that sites do not influence diameter at breast height of P. africana trees (p > 0.05) or total tree height. The bark diameter of harvested trees and the bark diameter of unharvested trees varied significantly by site (p 0.05). In contrast, the annual growth rate of bark differed with altitude;the highest rate was observed in trees growing at high altitude (2.97 ± 0.9 mm/yr) compared to 2.23 ± 0.74 mm/yr at low altitude. In view of these results, this study indicates that a half-rotation of 7 years could allow an effective reconstitution of the bark of Prunus africana at the second passage on the remaining side of the same stem.

桃(Prunus persica(L.) Batsch.)品种核心种质的构建与评价

为构建桃品种核心种质,通过对56份桃（Prunus persica（L.） Batsch.）初级核心种质的形态农艺性状数据（MOR）和SSR等位基因数据的分析,研究了不同聚类取样方法和完全随机取样方法下9种取样比例的遗传多样性指数、保留比例及各频率段等位基因的丢失比例。结果表明：聚类取样的方法优于完全随机取样,并以在80%的取样比例下MOR结合SSR数据聚类取样的效果最好,利用此方案构建的桃品种核心种质共包括45份材料,该核心种质的基因遗传多样性指数最高,保留了初级核心种质100%的形态农艺性状和96.6%的SSR等位基因,在出现频率低于0.05的等位基因中共丢失了2个等位变异,保留了出现频率在0.05-0.10的所有等位基因;利用6个数量性状对所构建的核心种质的代表性检测表明所构建的核心种质很好地代表558份桃原始种质的遗传变异。

普通杏(Prunus armeniaca)种质资源数量性状的遗传多样性分析

【目的】种质资源的遗传多样性研究是资源工作的核心，了解和掌握种质资源资源多样性，对于资源收集、管理、发掘、利用方面具有重要意义。【方法】对219份普通杏种质资源的11个性状进行了相关分析、主成分分析和聚类分析。【结果】普通杏种质资源各性状变异系数的变幅为15．7％。42．2％，其中可溶性固形物含量的变异系数最小，平均单果质量的变异系数最大。相关性分析得出：平均单果质量与叶柄长度、叶片长度和叶片宽度呈极显著正相关；可溶性固形物含量与可溶性糖呈极显著正相关：维生素C含量与可溶性固形物含量呈极显著正相关．与1a生枝粗度呈显著负相关。主成分分析结果表明：11个性状可以综合为4个主成分，前4个主成分累计贡献率达58．65％．第1主成分反映叶片因子，第2主成分反映枝条因子，第3、第4主成分反映的是品质因子。根据聚类分析把219份杏种质资源划分为6大类群：第1类种质群的主要特点是叶片较大：第Ⅱ类种质群的特点是果实品质性状较好．但是果实平均单果质量小；第Ⅲ类种质群的特点是果实平均单果质量大：第V类种质群的特点是果实品质好：第Ⅵ类种质群的特点是叶片较大且1a生枝又粗又长。【结论]普通杏种质资源的主要数量性状的变异较大，遗传多样性较丰富。

基于优化LDSS法的中国李(Prunus salicina)初级核心种质构建

核心种质的构建不仅能够提高种质资源的保存效率、方便资源管理,而且有利于种质资源的深入研究和种质创新。以国家果树种质熊岳李杏圃中保存的405份中国李为材料,依据46个农艺性状的鉴定数据,在按品种类群和杂交类型分组的基础上采用S策略和优化后的最小距离逐步取样法(ILDSS)经2次抽样构建出中国李初级核心种质。该核心种质样本集由97份种质材料组成,占总体样本比例约24%。对核心种质群体的代表性进行检测,结果表明该核心种质群体能够代表中国李原种质资源的遗传多样性及其群体结构。平均多态位点百分率、平均Nei’s遗传多样性指数、平均Shannon-Weaver多样性指数、极差符合率、变异系数变化率、均值差异百分率、方差差异百分率和主成分分析(散点分布图)等8项指标能够有效地评价核心种质的遗传多样性和代表性。

Population Genetic Structure in Apricot (Prunus armeniaca L.) Cultivars Revealed by Fluorescent-AFLP Markers in Southern Xinjiang,China

Population-wide genetic structure was studied using fluorescent-AFLP markers on 85 apricot （Prunus armeniaca L.） cultivars collected from Kuche, Kashi, Hetian in the Tarim Basin, southern Xinjiang Uygur Autonomous Region of China. The purpose of this study was to determine the genetic structure and genotypic diversity among the different eco-geographical populations. Based on the results from this study, 8 pairs of fluorescent-AFLP primers showed clear electrophoregram and high polymorphism amongst the 64 pairs of EcoR Ⅰ/Mse Ⅰ （Mse Ⅰ - a FAM fluorescent marked primer） primers screened. There was a significant polymorphic difference for the same primer pair in different populations and for the same population with different primer pairs. The percentage of polymorphic loci （P） at species level was higher than Kuche, Hetian, Kashi population levels, respectively. The Nei＇s gene diversity index （H） and Shannon＇s information index （I） at species level were higher than those of Kuche, Hetian, and Kashi at population level, respectively. H and I of Kuche population were the highest amongst the three populations. Apricot population genetic diversity was found mainly within the population, Genetic differentiation coefficient between populations （GST） was 0.0882. Gene flow Nm between the populations was 5.1689. Population genetic identity was between 0.9772-0.9811 and genetic distance was between 0.0191-0.0232. These results further indicated that the similarity between populations was higher and the genetic distance between populations was smaller. The UPGMA cluster analysis indicates that the geographical populations at Kuche, Kashi, Hetian were relatively independent Mendelian populations. Concurrently, there was also partial gene exchange between the populations. All the evidences indicated that the genetic diversity in Kuche population was the highest, suggesting that it could be a transition population from wild apricot to cultivated apricot. There were abundant genetic diversities in apricot cultivar populations in southern Xinjiang, China, which provide promising germplasm for further breeding and theoretical basis for biodiversity conservation and utilization for apricot population in this area.

普通杏(Prunus armeniaca)初级核心种质资源的构建及评价

核心种质的构建不仅能够提高种质圃资源的保存效率、方便资源的管理,而且有利于种质资源的深入研究和种质创新。以国家果树种质熊岳李杏圃中保存的447份普通杏为材料,利用40个农艺性状的鉴定数据,对核心种质构建的几种聚类取样方案进行比较,明确了杏初级核心种质构建的最佳取样方案。在按品种类群分组的基础上,采用S策略经过多次聚类抽样,获得由111份种质材料组成的初级核心样本集,占总体样本比例25%。对该初级核心种质遗传多样性进行检测和评价,结果表明本研究所构建的初级核心种质能够很好地保留普通杏种质资源的遗传多样性。

Cloning and Expression of a cDNA Encoding Endopolygalacturonase from Feicheng Peach (Prunus persica)

Polygalacturonase (PG,EC3.2.1.15) is the key cell wall hydrolase in fruit ripening. The identification and characterization of a full length cDNA (pMT18) encoding for PG from Feicheng peach (Prunus persica (L.) Batsch cv. Feicheng) is described. The pMT18 clone is 1188 bp in length, with an open reading frame of 393 amino acids. The homology and phylogenetic analyses indicate a remarkable similarity between peach PG and other ripening related PG. And seven consensus sequences have revealed in peach PG compared to the PG from other plants. However, the profound divergence with other PG and the unique structure features suggest that peach PG probably belongs to a new evolutionary class. In RT PCR analysis, pMT18 related RNA was undetectable in leaves, and was much abundant in ripe fruits. The ripening specific expression pattern of this cDNA will be useful in investigating the roles of PG in fruit ripening and developing a transgenic peach with the improved post harvesting quality in the future.

半干旱黄土丘陵区天然次生灌木山桃(Prunus davidiana)与山杏(Prunus sibirica L.)叶片气体交换参数日动态差异

以半干旱黄土丘陵区5年生天然次生灌木山桃(Prunus davidiana)及山杏(Prunus sibirica L.)作为研究材料,系统比较了两树种叶片气体交换参数的日变化特征,分析了其光合作用和蒸腾作用与环境因子的关系。结果表明:山桃叶片气体交换参数日变化特征与山桃有所差异,山桃除蒸腾速率(Tr)外其它生理参数呈单峰曲线,山杏的日变化类型均呈双峰曲线。两树种光合速率(Pn)在下午明显下降,其原因主要是受到非气孔限制。山桃Pn的日均值((7.64±3.69)μmo.lm-2.s-1)比山杏((5.29±2.97)μmo.lm-2.s-1)高出46%,Tr的日均值((2.21±1.02)mmo.lm-.2s-1)比山杏((1.58±0.57)mmo.lm-.2s-1)高出40%左右,水分利用效率(WUE)的日均值相差不大,分别为(2.89±1.52)μmo.lmmol-1,(2.54±1.37)μmo.lmmol-1。多元回归及相关分析表明,影响光合作用与蒸腾作用的最重要因子是光合有效辐射强度,其次是大气CO2浓度;光合作用与蒸腾作用参数之间也有明显的相关性。结论:山桃与山杏表现出具有较高光合速率,较低蒸腾速率和较高水分利用效率的生理特征,因而在半干旱黄土丘陵区都有较好引种栽培与开发利用潜力。

Seed germination and seedling development of Prunus armeniaca under different burial depths in soil

A semi-greenhouse study was conducted to understand the effects of soil burial depth on seed germination and seedling development. The seeds of wild apricot （Prunus armeniaca） were buried at the soil depths of 0-cm, 4-cm, 8-cm, and 12-cm, respectively, to simulate the seed hoarding behavior of rodents in the field. The results revealed that the rates of seed germination and established seedlings from buried seeds were both the highest in 4-cm burial depth group, and then decreased with increasing soil depth. The number of rotten seeds increased in deeper burial depth. It is unfavourable for seed germination at 0-cm burial depth （i.e., seeds were laid on soil surface）. There was insignificant effect of burial depth on growth of established seedlings. The results from this study indicated that proper burial depth in soil would be helpful for the seed germination and seedling growth. The seedlings derived from buried seeds at shallower depth （4 cm） in this research have advantage in their early development.

防除杏树(Prunus armeniaca L.)冰核细菌药剂筛选及花期防霜效果

采用vali结冻法和含菌平板培养法，从9种供试药剂中筛选出1号、2号、3号、5号、7号5种对INA细菌触杀及破坏冰蛋白作用的药剂。将5种筛选的药剂于日光温室和田间进行药剂防霜试验研究，结果表明，日光温室霜冻温度为-4℃时，5种药剂中3号、7号防霜效果显著，分别为47．05％～67．74％和49．44％～69．33％。3号、7号分别提高座果率12．25％～14．83％和4．69％～11．36％，与对照相比差异达显著水平。大田温度为-6．5℃时，5种药剂中3号的防霜效果为21．80％，提高座果率9．17％。与对照相比达显著水平。

欧洲李(Prunus domestica)及其近缘种的孢粉学研究

运用扫描电子显微镜(SEM)系统观察了李属(Prunus)欧洲李(P.domestica)及其近缘种共13份试材的花粉形态,并采用平均连锁法(average linkage)对花粉的9个数量性状和2个质量性状进行聚类分析。观察结果显示,供试欧洲李的花粉均为单粒花粉,中等大小,等极,辐射对称,极面观为近圆形或圆形,赤面观均为椭圆形,表面纹饰由不规则条脊和散落于条脊间的穿孔组成,与其近缘种差异显著。花粉具3-孔沟环状萌发孔(tri-colporate),属N3P4C5类型,仅在耶鲁尓品种观察到个别花粉具4条萌发沟。对孢粉数量指标进行方差分析,结果表明欧洲李花粉形态与其近缘种存在明显的差异。聚类分析将供试材料分为二组,即多倍体组和二倍体组,经分析认为野生欧洲李与黑刺李亲缘关系近,野生欧洲李可能包含了黑刺李的种质,而栽培欧洲李可能由野生欧洲李演化而来。最后根据花粉形态对李属供试种的演化进行了讨论。孢粉资料结合聚类分析是进行李属种间亲缘关系及演化途径研究的有效手段。

Study on the Daily Change of Photosynthetic Rate for Prunus domestica × armeniacain Different Seasons

[Objective] The aim of this study was to explore the daily change of photosyntheticratefor Prunus domestica ×armeniacain different growing seasons. The study can provide theoretical basis for arid area high yield and quality cultivation.[Method] The photosynthetic physiological properties of leaves of different types of Prunus domestica × armeniaca were measured by the Li-6400 portable photosynthesis system indifferent seasons. By this method could analysis of photosyntheticcharacteristicsfor different types of Prunus domestica×armeniaca in different seasons.[Result] Daily change of photosyntheticrate（Pn） for Prunus domestica×armeniaca in differentseasons showed a ＂double-peak＂ curve. The peak values were at 10：00 and16：00. The Pn of ‘Fengweihuanghou＇, ‘Konglongdan＇, ‘Weihou＇, ‘Weiwang＇ and‘Weidi＇ reached the maximum in July, theywere 13.75, 14.76, 12.96, 13.3, and 11.9μmol/（m^2·s）, respectively. The Pn of Prunus domestica×armeniaca reached minimumin August, they were 9.78, 10.71, 12.02, 10.43 μmol/（m^2·s）. The Pn overall average of ‘Konglongdan＇ was highest,it reached 12.65 μmol/（m^2·s）.The Pn overall average of ‘Weiwang＇ was lowest, it reached 11.31μmol/（m^2·s）. There were extremely significant positive correlation between the Pn and Gs（P0.01）. [Conclusion] Daily change of photosyntheticrate for Prunus domestica ×armeniaca in differentseasons showed a ＂double-peak＂ curve, showing significant phenomenon of ＂midday depression＂.The photosynthesis intensity of Prunus domestica ×armeniaca was strongest in July, and the photosynthesis intensity was weakest in August. ‘Konglongdan＇showed the strongest photosynthesis capacity, ‘Weihou＇ and ‘Weiwang＇, followed.There were highest correlation between the Pn and stoma conductance（Gs）.

ISSR Analysis of Genetic Relationship of Germplasm Resource in Prunus mume Sibe. et Zucc

Using ISSR technique to analyze the diversity and genetic relationship of germplasm resources in 39 Prunus mume Sibe. et Zucc., the result showed that 10 primers were screened with high resolution from 51 primers, 120 fragments were amplified, of which 98 were polymorphic loci, accounting for 81.67% of total. Tested materials were divided into 3 classes, as was fundamentally accorded with the traditional classification base on horticulture. There was no obvious difference in geographic relationship among the clustering results.

Adaptive responses of Acer ginnala, Pyrus ussuriensis and Prunus davidiana seedlings to soil moisture stress

One-year-old seedlings of Amur maple (Acer ginnala Maxim), Ussurian pear (Pyrus ussuriensis Maxim) and David peach (Prunus davidiana Carr) were planted in pots in greenhouse and treated with four different soil moisture contents (75.0%, 61.1%, 46.4% and 35.4%). The results showed that net photosynthesis rate (NPR), transpiration rate (TR) and stomatal conductance (Sc) of seedlings of the three species decreased with the decease of soil moisture content, and Amur maple seedlings had the greatest change in those physiological indices, followed by Ussurian pear, David peach. Amur maple and Ussurian pear seedlings also presented a decrease tendency in water use efficiency (WUE) under lower soil moisture content, whereas this was reversed for David peach. Under water stress the biomass allocation to seedling root had a significant increase for all the experimental species. As to root/shoot ratio, Amur maple seedlings had the biggest increase, while David peach had the smallest increase. The leaf plasticity of Amur maple seedlings was greater, the leaf size and total leaf area decreased significantly as the stress was intensified. No significant change of leaf size and total leaf area was found in seedlings of Ussurian pear and David peach. It was concluded that Amur maple was more tolerant to soil moisture stress in comparison with David peach and Ussurian pear.