To deepen our understanding of the role of the microhabitat in seedling colonization, we analyzed the relationship between microhabitat factors and the natural renewal seedling traits of 1-year-old Tianshan spruce（Picea schrenkiana var. tianschanica） seedlings in the central northern slope of the Tianshan Mountains. In addition, we explored the influence of microhabitat factors on seedling traits via ranking analysis. Our results identified 11 microhabitat factors, namely, litter thickness, soil compaction, herb height, herb cover, moss cover, litter cover, altitude, root disc layer thickness, soil weight, soil phosphorus, and soil volume, that significantly affected the seedling traits of natural-regenerated 1-year-old Tianshan spruce seedlings. These factors explained 56.01% of seedling variation, with litter thickness, moss cover, soil compaction, and soil weight accounting for 55.13%. During the natural renewal colonization of Tianshan spruce, the type of ground cover and degree of soil loosening had a strong impact on the traits of 1-year-old seedlings.

Schrenk spruce was the main constructive species of forest community in Mont Tianshan, which plays an important role in maintaining the integrity of forest ecosystem in Mont Tianshan.In order to deepen the understanding of the effects of microhabitat changes on the functional traits of spruce seedlings in Mont Tianshan, and to explore the microhabitat disturbance measures that can promote the successful settlement of schrenk spruce seedlings, the one-year-old seedlings of schrenk spruce were studied in this paper, the functional characters of schrenk spruce seedlings were compared with those of natural regeneration seedlings under different conditions of artificial disturbance in microhabitat by means of artificial disturbance experiment in field and harvest of whole seedlings.The results showed that: compared with the human disturbance in the micro-habitat, the specific root area, root tissue density, specific stem length, rhizome length ratio, average leaf length and specific leaf area of seedlings under different interference conditions increased to varying degrees,the tissue density of roots,stems and leaves all decreased to varying degrees,and the difference reached a significant level（P ＜0.05）. The use of measures to add carbon in topsoil,break root mat layer and high-temperature carbonization of topsoil micro-habitats can effectively promote the development of the root,stem and leaf functional characteristics of schrenk spruce seedlings in the direction that was conducive to successful colonization. Among them,adding carbon in topsoil interfer-ence was the most suitable micro-habitat interference measure.

Carbohydrate content and metabolism-related enzyme activities were analysed in walnut fruits during fruit growth by artificial manipulation of the leaf-to-fruit ratio (LFR) to investigate the relationship between carbohydrate utilisation and LFR. LFR significantly affected glucose and sucrose content, and sucrose synthetase (SS) activity in the pericarp or kernel. When the leaf number was the same, sucrose content and SS activity in the pericarp and kernel decreased with increasing fruit load, while glucose and fructose content and acid invertase (AI) activity in the pericarp increased gradually. When the fruit number was the same, glucose and sucrose content and SS activity in the pericarp and kernel increased gradually as the number of leaves increased, while fructose content and AI and sucrose phosphate synthetase (SPS) activity in the pericarp increased, thereby indicating that enhanced AI activity in the pericarp improved the competitive ability of the sink when LFR was low during the fast fruit-growing period, while, high AI activity rapidly decomposed sucrose into hexose to supply the energy required for cell multiplication and growth during the fruit fast-growing period, when LFR was high. During the oil transformation period, the increase in sucrose content in the pericarp resulted from SS and SPS activities.

以'贝尔奇卡金Belgica Aurea'、'金皇帝Gold King'、'牢苏尼阿纳Lawsoniana'3个哈克勒雷冬青Ilex×altaclerensis品种13 a生嫁接植株成熟叶片为试材,采用LI-6400光合仪测定其净光合速率(Pn)、蒸腾速率(Tr)、胞间CO2浓度(Ci)、气孔导度(Gs)等光合参数日变化,测定叶片相关生理指标,并进行相关性分析.结果表明:3个哈克勒雷冬青品种的Pn受生理及环境因子不同程度的影响,影响Pn的主要生理因子是Gs,环境因子为大气温度.3个品种的Pn日变化均呈双峰曲线,"午休"现象,原因主要是非气孔因素;Pn、Tr、叶绿素含量和比叶重均表现为'牢苏尼阿纳'>'贝尔奇卡金'>'金皇帝'.综上所述,'牢苏尼阿纳'光合生产能力最高,能够快速生长;'贝尔奇卡金'次之,且受环境影响最小;'金皇帝'综合光合性能最弱.

2019年4—11月,以美国山核桃品种'波尼'Carya illinoensis'Pawnee'1年生幼苗为试验材料,通过浇灌方式探讨0(CK)、0.3％、0.4％,0.5％,0.6％和0.7％(质量百分数)NaCl处理对美国山核桃幼苗的发育物候期及存活率的影响;2019年6—9月,分别选择0(CK)、0.3％和0.6％(质量百分数)NaCl对美国山核桃的10年生苗进行盐胁迫处理,探讨对其果实形态特征和果仁营养成分的影响.结果表明,当NaCl浓度达到0.7％时,美国山核桃幼苗的存活率仅为49.5％,宜选用低于0.7％的NaCl作为其可耐受浓度.对10年生苗的盐胁迫处理结果表明,随着NaCl浓度的增加,果实纵径、单果质量、种壳厚度、果仁蛋白质和还原糖含量均呈上升趋势,而脂肪和可溶性糖含量呈现出缓慢下降的趋势;除单果质量外,不同处理对果实品质的影响差异不显著(P?0.05);NaCl处理改变了果仁中棕榈酸、α-亚麻酸和顺-11-二十碳烯酸3种脂肪酸的相对含量,但不同处理对脂肪酸组成的影响差异不显著(P?0.05).以上研究结果可为美国山核桃在滨海盐碱地上的绿化及生态应用提供理论依据.

为了探究林火烈度和火后时间对喀纳斯泰加林林下草本层碳密度的影响,在喀纳斯自然保护区设置火干扰样地,采用收获法进行了生物量调查.分莎草科、禾本科、豆科和其他草类4个功能群进行草本地上碳密度对林火烈度的火后时间响应研究.结果表明:喀纳斯林泰加林草本层地上碳密度的范围为0.096～0.359 t/hm2.在3个演替阶段,莎草科和禾本科对草本层地上碳密度贡献率大;其他草类对草本层地上碳密度贡献率的范围为10.03％～40.97％;豆科对草本层地上碳密度贡献率最小,仅在针叶阔叶林阶段中低烈度火后51～84 a的林分中其贡献率较大.喀纳斯林草生态系统大部分林分处于针叶阔叶和针叶混交林阶段,草本层地上碳密度在不同烈度的火干扰下总体趋势为:低烈度>中烈度>高烈度,表明低烈度火干扰有利于草本植物的生长.3个演替阶段草本功能群地上碳密度对林火烈度的火后时间响应并不相同,但草本层地上碳密度随着火后时间的增加总体呈减小趋势.高烈度火干扰对草本层地上碳密度的影响最大,且不利于保持或提高森林的生产力.通过清除林下凋落物将林火烈度控制在中、低烈度范围内,有利于提高草本层的碳汇功能.

The Gly-Asp-Ser-Leu (GDSL)-lipase family is a large subfamily of lipolytic enzymes that plays an important role in plant growth and defense against environmental stress. However, little is known about their function in pecans (Carya illinoensis K. Koch). In this study, 87 CilGDSLs were identified and divided into 2 groups and 12 subgroups using phylogenetic analysis; members of the same sub-branch had conserved gene structure and motif composition. The majority of the genes had four introns and were composed of an α-helix and a β-strand. Subcellular localization analysis revealed that these genes were localized in the extracellular matrix, chloroplasts, cytoplasm, nucleus, vacuole, and endoplasmic reticulum, and were validated by transient expression in tobacco mesophyll cells. Furthermore, the analysis of the promoter cis-elements for the CilGDSLs revealed the presence of plant anaerobic induction regulatory, abscisic acid response, light response elements, jasmonic acid (JA) response elements, etc. The qRT-PCR analysis results in “Pawnee” with salt treatment showed that the CilGDSL42.93 (leaf) and CilGDSL39.88 (root) were highly expressed in different tissues. After salt stress treatment, isobaric tags for relative and absolute quantitation (iTRAQ) analysis revealed the presence of a total of ten GDSL proteins. Moreover, the weighted gene co-expression network analysis (WGCNA) showed that one set of co-expressed genes (module), primarily CilGDSL41.11, CilGDSL39.49, CilGDSL34.85, and CilGDSL41.01, was significantly associated with salt stress in leaf. In short, some of them were shown to be involved in plant defense against salt stress in this study.

The pecan is a salt-alkali-tolerant plant, and its fruit and wood have high economic value. This study aimed to explore the molecular mechanisms responsible for salt stress tolerance in the pecan grown under hydroponic conditions to simulate salt stress. The results showed that the photosynthetic rate ( P n) was reduced in response to salt stress, while the intercellular carbon dioxide concentrations ( C i) increased. The response of the pecan to salt stress was measured using iTRAQ (isobaric tags for relative or absolute quantitation) and LC/MS (liquid chromatography and mass spectrometry) non-targeted metabolomics technology. A total of 198 differentially expressed proteins (65 down-regulated and 133 up-regulated) and 538 differentially expressed metabolites (283 down-regulated and 255 up-regulated) were identified after exposure to salt stress for 48 h. These genes were associated with 21 core pathways, shown by Kyoto Encyclopedia of Genes and Genomes annotation and enrichment, including the metabolic pathways involved in nucleotide sugar and amino sugar metabolism, amino acid biosynthesis, starch and sucrose metabolism, and phenylpropane biosynthesis. In addition, analysis of interactions between the differentially expressed proteins and metabolites showed that two key nodes of the salt stress regulatory network, L-fucose and succinate, were up-regulated and down-regulated, respectively, suggesting that these metabolites may be significant for adaptations to salt stress. Finally, several key proteins were further verified by parallel reaction monitoring. In conclusion, this study used physiological, proteomic, and metabolomic methods to provide an important preliminary foundation for improving the salt tolerance of pecans.

经济林栽培学作为实践性较强的一门课程,在培养经济林产业应用型人才中具有重要作用,是园林专业及其相关专业的基础课程.为解决经济林栽培学课程教学过程中存在的信息量大、知识点多、学生不易掌握等问题,根据经济林栽培学课程特点,综合多种手段途径创建适合本课程教学的图片库.经济林栽培学课程教学图片库的建立不仅可以满足课程教学中教师"教"的需求,也可以满足学生"学"的需求;不仅可以提高课前教师制作课件的效率、丰富教学素材,也可以形成良好的课堂氛围,提高课堂教学效果;还可以提高学生课后学习的自主性,培养学生的自主学习能力.

In recent years, with the development of economy, the walnut industry has been developed rapidly, and China has become the world's first walnut producer and consumer country. However, there is a problem of single and blind application of chemical fertilizer in walnut production, which causes the lack of soil fertility and environmental pollution, and also affects the growth, fruiting, yield and quality of walnuts. In this thesis, different fertilization treatment experiments were conducted to address the problems of walnut fertilization, and through the study of its effects on walnut growth and photosynthesis, we aimed to provide suitable fertilization solutions for walnut production and promote the healthy and sustainable development of walnut industry. The experiment was conducted in a randomized group method with walnut as the research object. The effects of different fertilization conditions on walnut were comprehensively analyzed by observing the phenological stage, annual new growth, nutrient and photosynthesis of walnut leaves, and soil fertility measurement. The fertilizer application was beneficial to prolong the phenological period of walnut, and the two treatments of B (bio-organic fertilizer + foliarfertilizer) and C (bio-organic fertilizer + chemical fertilizer) mixed with bio-organic fertilizer had significant effects on the phenological period of walnut, and the two treatments prolonged the flowering period of male and female for 1 d each compared with other treatments without bio-organic fertilizer, which was beneficial to the pollination of walnut and thus improved the yield of walnut. The bio-organic fertilizer application significantly increased the nutrient level in walnut leaves, and treatment C had the best effect. The organic carbon, total nitrogen, total phosphorus and total potassium were 607.74 g/kg, 17.63 g/kg, 26.98 g/kg and 15.72 g/kg, respectively. In conclusion, it is concluded that bio-organic fertilizer is beneficial to expand canopy and improve soil fertility, as well as to improve soil fertility transformation and enhance the plant's ability to absorb fertility. Therefore, the application of bio-organic fertilizers with chemical fertilizers in walnut production should be vigorously promoted.

以一年生薄壳山核桃'Pawnee'的容器苗为试材,采用不同浓度的NaCl溶液0％(CK)、0.3％、0.4％、0.5％、0.6％、0.7％对其进行盐胁迫处理,确定耐受浓度.再以薄壳山核桃'Pawnee'幼苗为试材,采用不同NaCl浓度水平(0％、0.3％、0.6％和0.9％)胁迫处理,研究了盐胁迫对其物候期、叶片抗氧化酶活性和Na+/K+的影响,以期为薄壳山核桃栽培提供参考依据.结果表明:在0.3％NaCl处理后薄壳山核桃落叶时间比对照提早了26 d,且存活率与对照一致,均为97.1％;而盐浓度达到0.7％NaCl处理后植株的存活率为49.5％;NaCl浓度水平的升高显著增加'Pawnee'幼苗叶片中Na+/K+和脯氨酸(Pro)含量;另外,丙二醛(MDA)含量和超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性在处理前期的10 d或30 d,随NaCl浓度水平增大而增加;但在盐处理后期,尤其在高NaCl浓度水平(0.6％和0.9％)下,其活性随着胁迫处理时间的增加呈下降趋势.

运用电镜、内源萌发抑制物类型的生物学鉴定、TTC染色等方法进行天山花楸种子特性、种子吸水性、内源抑制物测定,研究天山花楸种子休眠的原因及可能存在的休眠类型.结果表明,天山花楸种子呈扁卵形,种皮较光滑.纵径在4.01～4.97 m m之间,横径在1.89～2.67 m m之间;千粒重在5.503～5.689 g之间;种子含水量为6.47％,种子的生活力为33.3％.种皮上的角质层和坚硬较厚的种皮会影响种子的透性.种子甲醇浸提液和水浸提液能显著抑制白菜种子萌发和幼苗的生长,其中水浸提液的抑制作用比甲醇浸提液更明显.天山花楸种子属小粒种子,且生活力较低,种皮机械障碍造成的物理休眠和种子内源抑制物是造成天山花楸种子休眠的主要因素.

以薄壳山核桃品种Pawnee幼苗为试材,探讨不同浓度NaCl(0、0.3％、0.6％和0.9％)处理对其叶绿素含量、光合作用、荧光参数及叶绿体超微结构的影响.结果表明,短期内低浓度水平(0.3％NaCl)处理可能使植株叶绿素的含量有所增加,但长期盐胁迫均会导致所有处理组中叶绿素含量的降低;NaCl胁迫显著削弱其光合作用,而0.3％NaCl处理下的净光合速率、细胞间隙CO2浓度、气孔导度的变化趋势基本相同,气孔因素可能是抑制其光合作用的主要因素.此外,不同浓度的NaCl处理均对叶绿体和类囊体等结构造成一定程度的损坏,且随着NaCl浓度和处理时间的增加而越发明显.

Fruit quality is known to be regulated by the balance between leaf number/area and fruit number, but less is known about the effects of fruit–bearing branch agronomic traits, particularly for walnuts (Juglans regia L.). We assessed nut quality, physiological and biochemical indexes of leaves, and microstructure of leaves and fruit stalks at various leaf–to–fruit ratios to gain insight into the relationships between branch agronomic traits and nut quality, to identify those traits that made a better contribution to nut quality and to find out the range of the leaf–to–fruit ratio and the object of fruit to be removed for thinning. We found that the top fruit on the fruit stalk had a higher longitudinal diameter and kernel weight than the bottom at the low leaf–to–fruit level, and branches with more pinnate compound leaves had a better capacity for carbohydrate assimilation and transportation to produce better quality fruits. Specifically, with the increasing leaf number, the branch diameter, total leaf area, net photosynthetic rate, chlorophyll content, fruit weight, fruit diameters, and kernel protein content also increased. Moreover, at the microscopic level, the fruit stalk vascular bundle, leaf thickness, palisade mesophyll thickness, and ratios of palisade mesophyll to spongy mesophyll thickness in the leaf also showed the same trend. Therefore, when the ratio of leaf area to the fruit number was less than 181.5 square centimeters per fruit on the branches, reducing the fruit number could improve the size and the crude fat content of fruits. While the ratio was more than 247.8 square centimeters per fruit, the fruit number had no significant effect on fruit quality, but increasing leaf area and branch diameter could improve the fruit size and yield.

海拔对物种多样性的影响是生态学领域研究的热点.通过对天山云杉(Picea schrenkiana Fisch.et Mey.)林地上植被进行调查,计算地上植被α多样性指数,分析物种多样性与海拔梯度间的相关性,为天山云杉林地上植被沿海拔梯度分布提供依据.分析得出,海拔1750～2150 m,共鉴别出64种植物,隶属32科;地上植被的物种数与密度随着海拔梯度的增加而逐渐减小.物种多样性指数与海拔梯度之间呈U型分布.海拔1750～1950 m,植物群落的相似系数在0.25～0.50间,属中等不相似性;其它海拔梯度间群落相似性系数0.00～0.25,属极不相似性.

By designing and conducting a series of temperature-controllable experiments in greenhouse, this work emphatically investigated how the positive or negative allelochemical effects of a key metabolic compound 3,4dihydroxyacetophenone (DHAP) from the needles of Picea schrenkiana would vary with environmental temperature. It was found that the alleochemical effect of DHAP on the germination, seedling growth, root development, endogenous plant hormone content and antioxidant enzyme activity of P. schrenkiana demonstrated an orientation duality identified by the existence of a compensation concentration at a certain temperature, which set up a boundary between promotional and inhibitory effect. As temperature increased from 10/2 degrees C up to 12/4, 14/6, 16/8, and 18/10 degrees C in turn, the compensation point of DHAP concentration would correspondingly shift from 0.32mM down to 0.28, 0.24, 0.21 and 0.19mM, respectively. Overall, this work will deepen and enrich the understandings to the uncertainty of allelochemical effects on P. schrenkiana regeneration due to climate warming, and provide some helpful suggestions to develop a scientific management strategy for boreal forest.

Based on 13 C isotope tracer technology, we investigated the 13 C abundance (δ 13 C), 13 C content ( 13 Camount), and new fixed 13 C percentage ( 13 CPCT) in different organs and different metabolic components in girdled fruit-bearing shoots at different stages of fruit growth and development in walnut. Our aim was to analyze the dynamic characteristics of carbohydrate assimilation, transportation, and utilization in different stages of walnut fruit growth and development. The results showed that (1) at 0 h after the feeding, δ 13 C, 13 Camount, and 13 CPCT in sucrose from the leaves were the highest and positively correlated with net photosynthetic rate of leaves (p < 0.05); (2) at 24 h after the feeding, δ 13 C, 13 Camount, and 13 CPCT in sucrose from the carpopodium reached their peak values; (3) δ 13 C, 13 Camount, and 13 CPCT in sucrose from the peel were lower than those of hexose at 48 h after feeding in the fast-growing stage, but they all reached maximum levels in peel sucrose at 48 h after feeding in the oil conversion stage; and (4) the highest δ 13 C, 13 Camount, and 13 CPCT were recorded in all carbohydrates from the seed kernel 48 h after feeding, among which the highest δ 13 C, 13 Camount, and 13 CPCT were recorded in sucrose. These results suggested that sucrose was the main form of carbohydrate assimilation and transportation in walnut fruit, and large amounts of sucrose are accumulated in the peel and in the kernel, where it is also the base for the transformation of oil. Additional key words: 13 C isotope, carpopodium, fruit development, photosynthesis, seasonal changes

塔里木盆地是核桃的主产区,又是沙尘暴源区及频发区;沙尘暴及沙尘暴后所产生的自然降尘(包括直径<10μm的颗粒物)能够在植物表面积累形成覆盖层,改变植物—气界面,影响植物的外部和内部结构.自然降尘多集中在春夏季,这正与核桃的生育期特别是花期相遇,自然降尘对核桃的生殖活动是否会带来不利影响尚不清楚,但相关研究已证明自然降尘会损伤果树叶片表面和内部结构,从而间接影响果树产量及品质.该文应用联苯胺-过氧化氢法研究核桃雌花柱头可授性;扫描电镜观察雌花器官和花粉的形态特征;利用荧光显微镜观察花粉萌发和花粉管生长情况,旨在探讨降尘对核桃雌花、雄花发育及授粉受精的影响.结果表明,降尘对雄花和雌花均有显著的抑制作用,导致花粉生活力下降(花粉生活力为20.13％),花粉孔受阻,花粉萌发率降低,花粉管形成所需时间延长.对核桃雌花柱头长度和可授性也有抑制作用,在开花过程中核桃柱头长度减少了0.25～0.80 mm.此外,柱头粘液减少,导致柱头萎缩,柱头上花粉量减少,柱头可授性减弱,雌花干燥加速.在新疆塔里木盆地,核桃开花期与沙尘暴同时发生,对核桃花器官、授粉和开花都产生了不利影响.

[目的]检验喀纳斯泰加林群落火成演替中草本层与林冠层物种的连锁关系,并探索其形成机制.[方法]以新疆喀纳斯国家级自然保护区内未受人为干扰的可识别的泰加林火成演替群落为对象,基于369个森林样地及其历史火干扰时间和火烈度调查,以环境、火干扰和林分因子为解释变量,草本层和林冠层物种多样性指数为响应变量,分别进行典范对应分析(CCA),并对草本层和林冠层的CCA排序第一轴得分值进行相关分析,探讨不同烈度火干扰后草本层与林冠层物种的连锁关系和随演替阶段的变化及其原因.[结果]1)火成演替群落的草本层与林冠层CCA排序第一轴得分值之间的相关性,在弱烈度和中烈度火干扰后达到显著水平(P=0.017<0.05,P=0.043<0.05),在强烈度火干扰后未达到显著水平(P=0.093>0.05);2)在强烈度火干扰后,火成演替群落的草本层与林冠层CCA排序第一轴得分值之间的相关性在演替前期达到显著水平(P=0.044<0.05),在演替中期和后期达到极显著水平(P=0.008<0.01,P=0.006<0.01);中烈度火干扰后,相应得分值的相关性在演替前期达到显著水平(P=0.043<0.05),在演替中期和后期达到极显著水平(P=0.006<0.01,P=0.004<0.01);弱烈度火干扰后,相应得分值的相关性在不同演替阶段均达到极显著水平(P=0.006<0.01,P=0.005<0.01,P=0.002<0.01);3)草本层和林冠层具有一致性响应且达到显著水平的因子,在强烈度火干扰后的演替前期、中期和后期分别有1、2和4个,在中烈度和弱烈度则均为3、4和5个.[结论]火干扰后,泰加林群落演替过程中的草本层与林冠层物种之间存在连锁关系,其原因可能是草本层和林冠层物种多样性格局对相同环境梯度的响应具有一致性.该连锁关系随火烈度增强而从强到弱,且随演替向前发展变得更加紧密.

Soil salinity is a serious abiotic stress worldwide. Pecan plants (Carya illinoensis K. Koch) have been suggested for cultivation in soils with high levels of salinity owing to their huge demand. To understand the potential molecular mechanisms in pecan in response to salt stress, RNA-sequencing technology was used to compare the transcriptomes of pecan plants treated with 0, 0.3 %, or 0.6 % NaCl solutions. The results indicated that 170,086 unigenes were obtained from pecan leaf cDNA samples. Based on the assembled de novo transcriptome, 53, 535, and 7358 differentially expressed genes (DEGs) were detected between untreated and salt-treated leaves at 8, 24, and 48 h, respectively. Because of the large number of DEGs across different contrasts, a Gene Set Enrichment Analysis was selected to identify gene pathways associated with salt treatment. A total of 1858 DEGs were enriched in 66 gene sets, including 22 up-regulated and 47 down-regulated gene sets in the salt treatment groups, compared with those in the control groups. The up-regulated gene sets were mainly involved in the response to salicylic acid; the regulation of the jasmonic acid-mediated signalling pathway during the short-term treatment (8 h); and the cellular response to hypoxia, cellular respiration, and RNA modification during the long-term treatment (24-48 h). The down-regulated gene sets were predominately associated with photosynthesis, water transport, and the metabolic biosynthetic process under salt stress. Genes related to the Really Interesting New Gene superfamily protein and F-box domain protein in the ubiquitin-dependent degradation pathway were significantly up-regulated or down-regulated in different periods of the regulating process. Overall, these results not only enrich genomic resources but also provide insights into the molecular mechanism in pecan under salt stress.