Growth Responses of Young Slash Pine (Pinus elliottii Engelm.) to N, P and K Fertilizers in Red-Yellow Soil in Jiangxi Province, China

During 1991~1995, the growth responses of young slash pine to N, P and K fertilizers and rational rate and ratio of fertilizers in yellow-red soil at Fengshushan Forest Farm, Jiangxi Province were studied. N fertilizer decreased the growth of slash pine, while P not only significantly improved the increment of bottom diameter, height and crown diameter, but also caused earlier canopy closure of the stand. It also had a sustainable effect in the next two years. Slash pine had the most significant response to the treatment of 200 kg P2O5 ha-1, in which tree height, bottom diameter and crown diameter (EW and SN) were increased by 22%, 35%, 20% and 18% in 1994, 21%, 25%, 10% and 10% in 1995, respectively, compared to the control.Although there was no remarkable response to K fertilizer, good growth response to the application of 100 kg P2O5 plus 100 kg K2O ha-1 existed and tree height, bottom diameter and crown diameter (EW and SN)were increased by 31%, 14%, 23% and 21%, respectively, in 1993, compared to the control.

Extraction and Content Determination of Shikimic Acid in Pinus elliottii Engelm

[Objective] The aim was to provide scientific basis for development and utilization of Pinus elliottii Engelm resources.[Method] The extraction process of shikimic acid in Pinus elliottii Engelm was studied,and the content of shikimic acid was determined by HPLC.The HPLC conditions were as follows;Alltima NH2 （5 μm,4.6 mm × 150 mm） column separation;the mobile phase was acetonitrile-2%H3PO4 （90：10）;the flowing velocity was 1 ml/min;test wavelength was 213 nm,the width of belt was 16 nm;reference wavelength was 300 nm,the width of belt was 80 nm.[Result] By the single factor and orthogonal tests,the optimum conditions were found as follows：ethanol concentration 60%,extraction temperature 75 ℃,solid-liquid ratio 1：25,extraction time 2.5 h.The extraction rate of shikimic acid was 1.49%.[Conclusion] Shikimic acid in Pinus elliottii Engelm could be used as a new resource to develop and utilize.

湿地松(Pinus elliottii Engelm.)的生态生物学特征

湿地松具有抗旱耐瘠薄、早期生长快的特点，因而被广泛引种并常用作植被恢复的先锋树种。通过广东省鹤山丘陵综合试验站的研究发现，湿地松纯林后期生长较慢，群落结构简单，生物多样性指数偏低，较易发生病虫害；湿地松落叶养分含量低，分解慢，不利于植被恢复过程中土壤肥力的提高。因此应根据不同目的营造不同类型的湿地松人工纯林或混交林，并对现有大面积的湿地松纯林进行林分改造。

Early selection efficiency for fiber dimensions and their relationships with growth and wood quality for Pinus elliotth Engelm.in southern China

A solid understanding of the efficiency of early selection for fiber dimensions is a prerequisite for breeding slash pine(Pinus elliottii Engelm.)with improved properties for pulp and paper products.Genetic correlations between size of fibers,wood quality and growth properties are also important.To accomplish effective early selection for size of fibers and evaluate the impact for wood quality traits and ring widths,core samples were collected from360 trees of 20 open-pollinated Pinus elliottii families from three genetic trials.Cores were measured by SilviScan,and the age trends for phenotypic values,heritability,early-late genetic correlations,and early selection efficiency for fiber dimensions,such as tangential and radial fiber widths,fiber wall thickness and fiber coarseness,and their correlations with microfibril angle(MFA),modulus of elasticity(MOE),wood density and ring width were investigated.Different phenotypic trends were found for tangential and radial fiber widths while fiber coarseness and wall thickness curves were similar.Age trends of heritability based on area-weighted fiber dimensions were different.Low to moderate heritability from pith to bark(~0.5)was found for all fiber dimension across the three sites except for tangential fiber width and wall thickness at the Ganzhou site.Early-late genetic correlations were 0.9 after age of 9 years,and early selection for fiber dimensions could be effective due to strong genetic correlations.Our results showed moderate to strong positive genetic correlations for modulus of elasticity and density with fiber dimensions.The effects on fiber dimensions were weak or moderate when ring width or wood quality traits were selected alone.Estimates of efficiency for early selection indicated that the optimal age for radial fiber width and fiber coarseness was 6-7 years,while for tangential fiber width and wall thickness was 9-10 years.

Antifungal Activity of Oleoresin and Fractions of Pinus elliottii Engelm and Pinus tropicalis against Phytopathogens

Microorganism resistance to the existing products is yet another difficulty that agriculturalists have to deal with. In this context, the search for new agricultural products that can fight phytopathogens has become increasingly important. Plants have played an important role in this process, because they can serve as a source of new compounds for drug discovery. Plants belonging to the genus Pinus produce an oleoresin that protects the plant against herbivores and pathogens. With a view to developing products that can combat fungal pathogens without harming the environment, this work aimed to evaluate the antifungal activity of the oleoresins and fractions of Pinus elliottii Engelm and Pinus tropicalis against phytopathogens. The methodology based on NCCLS M38-A standards aided antifungal activity assessment. The microdilution method helped to determine the Minimum Inhibitory Concentration (MIC) and Minimum Fungicidal Concentration (MFC). The oleoresins of P. elliottii and P. tropicalis afforded the most significant results—they displayed fungicidal activity against all the tested species. MIC values were promising, especially the MIC of the oleoresin of P. elliottii against S. rolfsii (1.95 μg·mL-1). The MIC values of the oleoresins of P. elliottii and P. tropicalis ranged from 1.95 to 1000 μg·mL-1 and from 31.25 to 250 μg·mL-1, respectively. Fraction PT2 of P. tropicalis furnished the best results among all the assayed fractions: MIC values lay between 125 and 500 μg·mL-11. In conclusion, the oleoresin of P. tropicalis is a promising source of new antifungal agents for application in the treatment of phytopathogenic infections.

马尾松(Pinus massoniana)、湿地松(Pinus elliottii)挥发性化学物质的昼夜节律释放

用TCT-GC/MS分析了马尾松、湿地松挥发性有机化合物的昼夜节律变化。结果表明:马尾松昼夜节律中检测到的挥发物主要是萜烯类化合物,其中单萜种类最多,且α-蒎烯和β-蒎烯含量约占整个挥发物的80%,其次是含氧化合物等。这些挥发物的释放高峰多数在10:30,少数在1:30;整个变化中有两个低峰期,即13:30和22:30。湿地松中检测到的挥发物组分与马尾松相似,多数释放高峰在12:00~15:00之间;另一些在6:00;α-蒎烯的释放高峰在3:00,而此时其它挥发性化合物的释放量最低。挥发物的释放也受到外界环境的影响,一定范围内随着温度的升高、湿度的减小,其释放量增加。

基于BIOME-BGC模型的红壤丘陵区湿地松(Pinus elliottii)人工林GPP和NPP

应用生物地球化学模型BIOME-BGC模型估算了1993～2004年红壤丘陵区湿地松林总第一性生产力(GPP)、净第一性生产力(NPP),并分析GPP、NPP年际变化对气候的响应以及未来气候变化情景下GPP、NPP的响应。结果表明,湿地松林1993～2004年GPP、NPP的总量变化波动于1777～2160g Cm-2a-1之间和453～828gCm-2a-1之间,平均值分别为1941g Cm-2a-1和695gCm-2a-1。在研究时段内,GPP、NPP有缓慢增长趋势,GPP、NPP总量平均值从1990年代初期(1993～1996年)的1826、687gCm-2a-1上升到21世纪初期(2001～2004年)的2026、693gCm-2a-1。这主要是由于研究时段内GPP、NPP对降水缓慢增长的正响应造成的。未来气候变化情景分析表明,CO2浓度倍增不利于湿地松林GPP、NPP的增长,但均不超过1.5%。在CO2浓度不增加条件下,GPP正向响应了降水单独变化和温度升高1.5℃且降水增加情景,正向响应NPP的情景条件是降水的单独变化;当CO2浓度倍增和气候改变时,预测的GPP正向响应了降水的变化,同时正向响应了温度升高1.5℃且降水变化;正向响应NPP的情景条件是降水的变化。

Study on the Mycorrhizal Formation in the Offspring Tissue Culture Seedling Bottle of Pinus elliottii with Lecanosticta acicola Resistance

[Objective] The research aimed to study the mycorrhizal formation in the offspring tissue culture seedling bottle of Pinus elliottii with Lecanosticta acicola resistance.[Method] The mycorrhizal formation of Pinus elliottii regenerated plant in vitro was studied,and the growth condition of regenerated plant was observed.[Result] The culture substrate and the inoculation amount of mycorrhizal fungi had the big influence on the mycorrhizal formation in vitro.After the root primordia were induced by Pinus elliottii caespitose shoots,it was best to transplant in the perlite substrate and inoculate Pisolithus tinctorius,which was favorable for the mycorrhizal formation.When the two blocks of Pisolithus tinctorius were inoculated in the perlite medium,the mycorrhizal formation rate reached 84.4%.The dichotomous branching short root was the most,and 12.49 roots were formed in every main root.The mycorrhizal formation improved the survival rate of regenerated plant domestication transplantation.The mycorrhizal regenerated plant grew well in the phytotron,and the root system was developed.[Conclusion] The research provided the basis for improving the survival rate of Pinus elliottii tissue culture regenerated plant with Lecanosticta acicola resistance.

施氮对湿地松(Pinus elliottii)林土壤呼吸和相关因子的影响

人类活动引起陆地生态系统氮输入水平持续升高,对全球碳循环产生影响。为探究氮素对土壤呼吸的影响,2010年6月至2012年1月,采用氮添加试验对亚热带湿地松林的土壤呼吸进行了研究。试验共设置4种氮添加水平:对照CK,0 g m^(-2)a^(-1);低氮LN,5g m^(-2)a^(-1);中氮MN,15 g m^(-2)a^(-1);高氮HN,30 g m^(-2)a^(-1);每月上、下旬采用Li-cor 8100测定土壤呼吸速率。结果表明:(1)氮添加对土壤呼吸有着显著的抑制作用,LN、MN和HN处理的土壤呼吸年累积量较CK处理分别降低了26.6%、23.7%和29.5%,而施氮处理间的土壤呼吸无显著差异;(2)林分生长期间(6-9月),施氮第1年的土壤呼吸所受抑制作用显著高于第2年同期的水平,显示施氮对土壤呼吸的影响随时间的推移而降低;(3)湿地松林土壤呼吸存在明显的季节动态,最大值出现在8月(356.32 mgCO_2 m^(-2)h^(-1)),最小值出现在1月(99.12 mg CO_2 m^(-2)h^(-1)),施氮处理并不改变土壤呼吸的季节性变化规律;(4)CK处理林分中,土壤呼吸与土壤温度间存在极显著的指数关系,而与土壤湿度无显著相关。施氮处理没有改变土壤呼吸与土壤温度之间的相互关系,但抑制了土壤呼吸的温度敏感性(Q_(10));(5)施氮处理显著减少了林分凋落物量、土壤微生物碳、氮量,并轻微抑制了细根生物量,这些改变导致了土壤呼吸的下降。上述结果表明施氮会显著抑制亚热带湿地松林的土壤呼吸速率,而这种抑制作用将随着时间的推移而降低。

Ultrastructural Study on Development of Needle Resin Ducts in Pinus elliottii Engel.

The development of needle resin ducts of Pinus elliottii was studied using electron microscope. The results indicate that the resin duct development encompasses at least three distinctive development stages: the stage of initial cells, the stage of middle lamellae expansion and intercellular space appearance, and the stage of cavity enlargement and the resin duct formation. During the whole development stages, all kinds of organells in the duct cells show different ultrastructural features and regularity, among them the plastids' changing is the most striking one. On the basis of analysing the ultrastructural features of developing resin duct cells, the pattern of duct cavity formation, possible sites of resin synthesis, the manner and way of the resin elimination from the protoplast are discussed.

Effects of Ground Mulching Treatments on Soil Moisture Content in Second-generation Seed Garden of Pinus elliottii

Different ground mulching treatments were designed to observe the effects on soil moisture content in a second-generation seed orchard of Pinus elliottii. The results showed that： （1） there were extreme differences in soil moisture content Ⅰ and soil moisture content Ⅲ, but no obvious difference in soil moisture content II was observed; and （2） the high-to-low order of soil moisture content Ⅰ under different ground mulching treatments was white film〉sawdust〉black film〉the control, and the highest value was higher than the lowest one by 26.69%; the high-to-low order of soil moisture content Ⅱ under different ground mulching treatments was white film〉black film〉sawdust〉the control, and the highest value was higher than the lowest one by 20.64%; and the high-to-low order of soil moisture content Ⅲ under different ground mulching treatments was black film〉white film〉sawdust〉the control, and the highest value was higher than the lowest one by 26.61%.

QTL detection for growth traits in Pinus elliottii var. elliottii and P. caribaea var. hondurensis

Quantitative trait locus （QTL） detection was carried out for growth traits in 122 F1 progenies of Pinus elliottiivar. elliottii （PEE） x tR caribaea var. hondurensis （PCH） hybrid. The PCH male parent linkage map contained 108 mark- ers in 16 linkage groups, while the PEE female parent contained 93 markers in 19 linkage groups. Sequence-related amplified polymorphism （SRAP）, microsatellite （SSR）, expressed sequence tag polymorphism （ESTP） and inter-simple sequence repeat （ISSR） were selected from an existing linkage map. Growth traits investigated were height at age five （HT05） and six years （HT06）, diameter at breast height at age five （DBH05） and six years （DBH06） and annual growth from age five to six years of height （AGHT） and diameter at breast height （AGDBH）. KruskaI-Wallis and interval mapping approaches were used to estimate levels of significance, the number of QTLs, the percentage of the phenotypic varia- tion explained by each of QTLs and their positions on the genetic linkage maps. Twenty six QTLs with significance levels p 〈 0.05 were detected on the parental maps for the six growth traits, which explained more than 15% of the phenotypic variation, suggesting an existence of major-effect genes. Several QTLs had the pleiotropy controlling more than one sin- gle growth trait. Overall, the proportion of phenotypic variation explained by QTLs ranged from 5.9% to 40.6% for HT05 and HT06, from 6.6% to 42.0% for DBH05 and DBH06 and from 5.8% to 22.3% for AGHT and AGDBH. The results from this study provide a basis for marker-aided selection （MAS） in PEE x PCH hybrids.

Benefit Assessment on Early Tapping of Pinus elliottii

The early growth of Pinus elliottii is rapid,so how to make Pinus elliottii generate economic benefit as quickly as possible is becoming increasing important.We conduct tapping test on man-made forest of perennial Pinus elliottii in Huashan forest farm,Huanjiang Maonan Autonomous County,Hechi City,Guangxi Zhuang Autonomous Region.The results show that the economic benefit of early tapping of Pinus elliottii is obvious,with high profitability;NPV(16 089.13)and IRR(39.2%)of forest stand tapped are much higher than that of forest stand not tapped;at the same time,it can bring considerable demand for labor,with good social benefits;tapping has a certain effect on the growth of Pinus elliottii,and turpentine production is closely related to the trunk diameter.

Monthly Changes in the Resin Yield of Semi-sib Families of Pinus elliottii

Monthly changes in the resin yield of semi-sib families of Pinus elliottii during 2013-2015 were studied.The results showed that from April to October,the resin yield of the P.elliottii families was the lowest in April and the highest in July.There were significant differences between various families in terms of resin yield.The change of resin yield was closely related to temperature,and the higher the temperature was,the higher the resin yield was.P.elliottii mainly produced resin from June to September.

Heritability Analysis of Growth Traits and Selection of Semi-sib Families of Pinus elliottii

Growth traits of semi-sib families of Pinus elliottii were studied.The results showed that there were extremely significant differences between the P.elliottii families in terms of tree height,DBH and volume( P < 0.01),and the families could be selected effectively.Both family heritability and single plant heritability of growth traits of P.elliottii were high.The family heritability of tree height,DBH and volume was 0.799,0.779 and 0.770 respectively,and their single plant heritability was 0.683,0.829 and 0.742 respectively.Among them,the family heritability of tree height was the highest,while the single plant heritability of DBH was the highest.The Duncan analysis of growth traits of the P.elliottii families revealed that families 12,7,15,4 and 6 were superior families and can be used as high-yield families.

AM Fungi and Piriformospora indica Improve Plant Growth of Pinus elliottii Seedlings

Pinus elliottii is an exotic afforestation pine extensively distributed in southern parts of China.In order to understand whether endophytic fungi can affect seedling growth of P.elliottii,Piriformospora indica(Pi),Funnelifcrmis mosseae(Fm),and Diversispora tortuosa(Dt)were inoculated respectively,and the non-inoculated group was set as control.The growth indexes,the contents of soluble sugar and soluble protein,and plant endogenous hormone levels in the leaves of P.elliottii,were analyzed.The results showed that Fm,Dt and Pi colonized the P.elliottii roots to form mycorrhizal structure and chlamydospores arranged in beads respectively.Three fungal inoculants exhibited the stimulated growth responses,whilst Dt illustrated the most positive effect on plant height,single fresh weight,trunk diameter and root system structure,compared with the control.On the other hand,the soluble sugar and soluble protein contents were increased distinctively in mycorrhizal plants.The endogenous IAA,GA3,ZR contents were increased,while the ABA contents were reduced in mycorrhizal plants versus non-mycorrhizal plants.The fungi-induced endogenous hormone changes triggered plant growth improvement of P.elliottii seedlings.This research unraveled the positive effect of AM fungi and P.indica on growth of pine seedlings,while,more application of endophytic fungi to fields needs to be explored.

Study on Pinus elliottii Plantations in Pengchang Forest Farm of Jingmen City

[Objectives]This study was conducted to improve the ecological and economic benefits of Pinus elliottii plantations in Pengchang Forest Farm, Jingmen City. [Methods] P. elliottii plantations in Pengchang Forest Farm in Jingmen City were selected as the research object, and the appearance and quantitative characteristics of P. elliottii community were studied and analyzed by a sampling method. [Results] Phanerophytes were the most in the P. elliottii community, accounting for 50%. In the community, except P. elliottii, the importance values of native plants were higher. The order of species diversity of P. elliottii community in Pengchang Forest Farm was herb layer, tree layer and shrub layer. The stress resistance of the community was weak, and strong intraspecific competition existed in P. elliottii. It is recommended to thin P. elliottii trees with insufficient lighting, poor growth potential and severely damaged tree body, and interplant Phoebe zhennan after thinning the P. elliottii plantations, so as to create a coniferous and broad-leaved evergreen mixed forest. [Conclusions] This study provides scientific support for thinning, tending, and forest management of P. elliottii plantations.

Influence of climate fluctuations on Pinus palustris growth and drought resilience

The longleaf pine(Pinus palustris Mill.)ecosystem is an endangered ecosystem in the southeastern USA,and efforts to restore the species are ongoing.However,in recent decades,the region has experienced drastic fluctuations between wet and dry growing season conditions from year to year,and it is not fully understood how these fluctuations have influenced the growth of P.palustris.To address this topic,we cored P.palustris trees in woodlands of southwest Georgia and used dendrochronology techniques to determine how climate fluctuations have influenced the growth and drought resilience of P.palustris.We also cored slash pine(Pinus elliottii Engelm.)trees in the same woodlands to compare growth between species.While P.palustris growth was less impacted by adverse climate conditions compared to P.elliottii,the strength of correlations between P.palustris growth and temperature,precipitation,and Palmer Drought Severity Index(PDSI)changed over time.In recent decades,climate conditions during the growing season became more influential on P.palustris growth than the previous year's conditions.This is concerning given that drought severity during the growing season has been increasing.Our results also indicate that P.palustris was less resilient to droughts during the 2000s and 2010s than to those of the 1950s.Under this new climate paradigm,our results suggest that P.palustris might be more susceptible to growth reductions and less resistant to droughts than once expected.This work highlights the importance of understanding the impact of novel climate conditions on P.palustris and has implications for restoration efforts,such as using silvicultural treatments that reduce tree vulnerability to drought(e.g.,thinning)and promote other climate-adapted species in mixture with P.palustris.

湿地松无性系松脂组分分析及评价

为从湿地松种子园现有的速生材用无性系中选择产脂力强、松脂品质高的优良无性系,并高效利用湿地松良种资源。该研究以湿地松第一代种子园内36个无性系为材料,测定其树脂质量流速以及胸径生长量,进一步采用GC-MS分析其松脂组分,并基于上述指标利用相关性分析、聚类分析对参试的36个无性系进行综合评价。结果表明:(1)共鉴别出了21种松脂成分,包括8种单萜成分和13种二萜成分。(2)相关性分析显示,树脂质量流速(RMR)与单萜含量显著正相关,与枞酸型树脂酸呈弱的负相关,与海松酸型树脂酸无明显关联。(3)从松节油含量、树脂质量流速、枞酸型树脂酸、海松酸型树脂酸4个维度对参试无性系进行聚类分析,可将36个无性系分为三大类,并且各类型间差异显著,第1类的表现要远好于其他两类。(4)在产脂力高的基础上,6-44、4-11-1、1-38、3-64四个无性系单萜含量高,4-11-1、3-64、2-0420、3-468四个无性系海松酸型树脂酸含量高,而无性系2-173枞酸型树脂酸含量较高。该研究定性分析了湿地松的松脂组分,定量评估了36个无性系的产脂力与组分含量,为湿地松脂用无性系的选择奠定了基础。

基于空间分析的湿地松遗传测定

该研究通过对湿地松自由授粉半同胞子代试验林的生长性状进行遗传测定,并估算家系及单株育种值筛选优良家系和优良单株。结果表明:试验点空间微环境效应显著,选择合适的空间分析模型可有效提高遗传参数估算的准确性。湿地松树高、胸径和单株材积的生长受中等偏弱的遗传控制,其单株狭义遗传力分别为0.12、0.13和0.12。根据参试家系的育种值排名筛选出3号、1号和42号3个优良家系,入选家系较对照家系的树高、胸径和材积生长遗传增益分别为1.14%、1.92%和4.62%。按1%的单株入选率并考虑其家系来源进行选择,共有238号、87号、45号、151号和184号5个优良单株入选,入选单株较试验林分群体的树高、胸径和材积生长遗传增益分别为2.23%、3.60%和10.55%。