干旱胁迫对4个刺柏品种抗旱生理指标的影响

以4个刺柏品种Junipenus scopulorum(代号1)、J.sabina(代号2)、J.ehinencis(代号3)、J.scopulorum var.(代号4)为研究对象,采用聚乙二醇(PEG-6000)模拟不同程度的干旱胁迫,测定其在不同干旱胁迫下,可溶性糖含量、可溶性蛋白含量、叶片质膜相对透性及相对含水量的变化。结果表明,随着干旱程度加深,相对含水量下降,可溶性糖、细胞膜相对透性增加,可溶性蛋白在低浓度胁迫时含量有所增加,高浓度胁迫时含量下降;相关分析结果显示可溶性蛋白与叶片的相对含水量之间存在极显著的负相关性,与相对电导率之间存在极显著的正相关性;可溶性糖和叶片内的相对含水量之间存在极显著的正相关性,叶片的相对含水量和电导率之间呈显著的负相关性;运用灰色关联分析方法综合评价4个刺柏品种之间的抗旱性能力的大小为2>3>1>4。     

青海省祁连圆柏天然林林地土壤生态化学计量特征

以青海省祁连圆柏天然林林地土壤为研究对象,分析土壤有机碳（SOC）、全N（TN）、全P（TP）及化学计量比对海拔与土层的响应及其与环境因子的关系,以期深入了解青海省祁连圆柏林土壤养分限制状况。结果表明:1）土壤SOC、TN、TP、C:P、N:P随海拔与土层深度增加均呈现减小趋势;不同海拔与土层深度间C:N无明显变化。SOC与TN在不同土层深度与海拔梯度间表现出协同变化特征;TP的空间变异性小。2）土壤理化性质、气候、植被因素对土壤C、N、P化学计量有显著影响（P＜0.05）。其中,土壤含水率是主要影响因素,解释了变异信息的44.0%。3）祁连圆柏天然林林地土壤C:P（57.96）、N:P（5.43）高于全国土壤平均水平（52.90、3.9）,说明土壤N有效性高,P素缺乏。林木正常生长受土壤中可利用性P限制。     

Reproduction of juniper (Juniperus polycarpos) in Khorasan Razavi, Iran

Juniperus species （juniper） are resistant to drought and have medicinal properties. In order to investigatethe condition of juniper reproduction and prevent a decline in its area, largely caused by problems in natural regeneration, the asexual reproduction of juniper has received special attention besides its sexual propagation. Among the six species of juniper in Iran, the most abundant are Juniperus polycarpos and J. excelsa. Juniperus polycarpos is ambi-sexual and J. excelsa unisexual. We show that collecting seeds in September provided for better germination than in November. In sexual propagation 82.0% and in asexual （graft） 47.6% success were achieved. Compared to a mixture of water, lime and hormones, a natural treatment of only water had better results. Diurnal change of temperature increased germination of juniper seeds over a constant temperature. Aphyllous stem cuttings from mature and old trees are less successful in rooting than leafy cuttings of juniper saplings. A treatment with Aaterra significantly reduced the percentage of rooted cuttings and total root length. Aliette, Fongarid, Octave, Benomyl, Delsene M and Maneb fungicides significantly increased the percentage of rooted cuttings but did not affect total root length. Autumn explants formed more calli than spring explants. Successful multiplication was achieved by treating buds with a mixture of 0.7% polyvinyl pyrrolidone （PVP） and 2% sucrose and cultured in a basal MS or WRC medium, with a maximum number of new buds. In consideration of extracted material of juniper species in remedy of infectious, fungus, contagious diseases as well as for drought resistance and longevity of this species in severe arid environmental conditions and various industrial applications, reproduction and seed production by micro propagation and biotechnology are necessary.     

Insecticidal activity of deoxypodophyllotoxin, isolated from Juniperus sabina L, and related lignans against larvae of Pieris rapae L

In the course of screening for naturally occurring insecticides from plants from the northwestern part of China, a petroleum ether extract of Juniperus sabina L was found to show insecticidal activity against fifth-instar larvae of Pieris rapae L. From the extract, an insecticidal compound was isolated by bioassay-guided fractionation. The compound was identified as deoxypodophyllotoxin (1) by comparison of its spectroscopic characteristics with literature data. In bioassays, 1 showed antifeedant activity against fifth-instar larvae of P rapae at 0.05-1.00 g litre(-1) and its AFC50 (concentration for 50% antifeedant activity) values at 12 and 48h were 0.170 and 0.060 g litre(-1), respectively. In that concentration range, all treated insects died within 48 h after treatment and compound 1 showed delayed insecticidal activity. At 0.015-0.100 g litre(-1), 1 showed insecticidal activity, with an LC50 of 0.020 g litre(-1). The related compound deoxypicropodophyllotoxin (2), however, showed lower antifeedant and insecticidal activities than 1 in bioassay. This indicated that the trans-lactone ring is an important moiety for enhancing activity in these compounds. Comparison of the insecticidal activities of 1 and another related compound, podophyllotoxin (3), suggested that varying the substituent at C-4 is an exciting possibility for synthesizing more potent analogues.     

川南地区丛生竹硬头黄竹带状皆伐对其生长及产量的影响

以长宁县硬头黄竹为研究对象,分别在龙头镇、竹海镇样地设置长度均为60 m,宽度为3 m、6 m、9 m皆伐带;3 m^6 m、6 m^9 m皆伐带间设置保留带,保留带宽度均为6 m;另外在样地附近设置一个6 m×60 m对照带。采用机械式带状皆伐1年后,通过调查和数据处理,分析其生长状况,显著性特征、生物量(地上部分)。结果表明:(1)两个样地中均发萌枝,且萌枝面积均为9 m皆伐带>6 m皆伐带>3 m皆伐带。从龙头镇来看,各皆伐带和保留带的发笋量均明显高于对照带,最大为6 m^9 m保留带,达到4 976±97株·hm-2;从竹海镇来看,3 m皆伐带、3 m^6 m保留带、6 m^9 m保留带发笋数高于对照带,6 m^9 m保留带发笋数最高,达到11583株·hm-2。(2)单因素方差分析(ANOVA)和多重比较表明,龙头镇和竹海镇竹笋平均胸径除6 m皆伐带和9 m皆伐带间差异不显著外(p>0.05),其他每个带之间差异均显著(p<0.05);龙头镇竹笋平均高除3m皆伐带和6m皆伐带之间、6 m皆伐带和9m皆伐带之间差异不显著外(p>0.05),其余各带之间差异均显著(p>0.05),竹海镇竹笋平均高除6 m皆伐带和9 m皆伐带之间差异不显著外(p>0.05),其余各带之间差异均显著(p<0.05)。(3)根据张鹏等在长宁县对硬头黄竹胸径与生物量拟合的指数回归模型,可以计算出经过带状皆伐改造试验后,龙头镇3 m^6 m保留带、 6 m^9 m保留带1 a生竹每公顷产量分别比对照提高了92.76%、175.21%。竹海镇3 m^6 m保留带、 6 m^9 m保留带1a生竹每公顷产量分别比对照提高了111.89%、161.58%。(4)通过本试验对该地硬头黄竹进行带状皆伐改造,发现6 m^9 m保留带竹林长势最好,生物量最高,改造效果最好。     

Dual extraction of essential oil and podophyllotoxin from Juniperus virginiana

The leaves (needles) of eastern red cedar (Juniperus virginiana L.) contain two important natural products: essential oil and podophyllotoxin. The hypothesis of this study was that it may be possible to extract both essential oil and podophyllotoxin from the leaves of the tree, by using a dual extraction method. Podophyllotoxin was obtained from the leaves following steam distillation of the leaves to produce the essential oil, indicating that steam distillation did not degrade podophyllotoxin. Furthermore, a product with 6% purity podophyllotoxin was obtained from the steam-distilled plant material, demonstrating the possibility for the establishment of an industrially economic protocol for dual extraction of these two natural products. Our study demonstrated that J. virginiana leaves, currently a waste-product from the timber industry, could be sequentially extracted for essential oil and podophyllotoxin and utilized as a by-product instead. We also found that the J. virginiana heartwood (a traditional source for cedarwood essential oil) does not contain podophyllotoxin. This is the first study to report both podophyllotoxin and essential oil in J. virginiana, and the first report on the dual extraction of these two natural products from the same biomass samples.     

辐射松、马尾松、长叶松与晚松人工林的生长规律比较研究

对九峰试验林场的辐射松、马尾松、长叶松及晚松人工林生长规律的研究结果表明 :长叶松生长最慢 ,而不宜大面积发展 ;辐射松、马尾松与晚松均表现较好 ,且辐射松与晚松材积生长速率高于马尾松 ,至 2 2a后 ,辐射松材积的生长速率将超过晚松 ;辐射松 4a时胸径连年生长量最大 ( 1 85cm) ,树高速生期为 1 2～ 1 6a,材积速生期为 1 4～ 1 7a,数量成熟龄在 40a之后 ;马尾松 4a时胸径连年生长量达最大 ( 1 30cm) ,1 3a树高连年生长量达最大 ( 3 5 0m) ,材积连年生长量 2 8a最高 ( 0 0 1 60 1m3) ,数量成熟龄为 35～ 40a ;晚松胸径连年生长量在第 3年达最大 ( 1 85cm) ,平均生长量 9a时达最大 ( 1 0 8cm) ,树高速生期为 3～ 8a ,材积速生期为4～ 1 5a ,数量成熟龄为 2 5a。     

Tree ring based drought variability in Northwest Tajikistan since 1895 AD

Determining the mechanisms controlling the changes of wet and dry conditions will improve our understanding of climate change over the past hundred years, which is of great significance to the study of climate and environmental changes in the arid regions of Central Asia. Forest trees are ecologically significant in the local environment, and therefore the tree ring analysis can provide a clear record of regional historical climate. This study analyzed the correlation between the tree ring width chronology of Juniperus turkestanica Komarov and the standardized precipitation evapotranspiration index(SPEI) in Northwest Tajikistan, based on 56 tree ring samples collected from Shahristan in the Pamir region. Climate data including precipitation, temperature and the SPEI were downloaded from the Climate Research Unit(CRU) TS 4.00. The COFECHA program was used for cross-dating, and the ARSTAN program was used to remove the growth trend of the tree itself and the influence of non-climatic factors on the growth of the trees. A significant correlation was found between the radial growth of J. turkestanica trees and the monthly mean SPEI of February–April. The monthly mean SPEI sequence of February–April during the period of 1895–2016 was reconstructed, and the reconstruction equation explained 42.5% of the variance. During the past 122 a(1895–2016), the study area has experienced three wetter periods(precipitation above average): 1901–1919, 1945–1983 and 1995–2010, and four drier periods(precipitation below average): 1895–1900, 1920–1944, 1984–1994 and 2011–2016. The spatial correlation analysis revealed that the monthly mean SPEI reconstruction sequence of February–April could be used to characterize the large-scale dry-wet variations in Northwest Tajikistan during the period of 1895–2016. This study could provide comparative data for validating the projections of climate models and scientific basis for managing water resources in Tajikistan in the context of climate change.     

Extractives ofJuniperus chinensis L. I: Isolation of podophyllotoxin and yatein from the leaves ofJ. chinensis

Two compounds, yatein and podophyllotoxin, were isolated from the chloroform-soluble fraction in the methanolic extractives of byakushin (Juniperus chinensis L.) leaves for the first time.This report was presented at the 47th annual meeting of the Japan Wood Research Society, Kochi, 1997     

刺柏叶水提液对高羊茅的化感作用及其GC-MS分析

为证实刺柏(Juniperus formosana Hayate)叶对高羊茅(Festuca arundinacea Schreb.)的化感作用,采用室内生物测定法研究刺柏叶水提液对高羊茅种子萌发、幼苗生长的影响,并采用气相色谱-质谱(GC-MS)联用技术对刺柏叶水提液化学成分进行分析。结果表明:刺柏叶水提液对高羊茅种子发芽率、发芽势和发芽指数的影响表现出"低促高抑"的效应,对高羊茅种子活力指数表现出抑制效应。当水提液浓度为0.100 g·mL^-1时,对高羊茅种子发芽率、发芽势、发芽指数、活力指数的抑制率分别达到39.24%,80.36%,74.92%,87.41%。刺柏叶水提液对高羊茅幼苗根长和苗高生长也表现出抑制效应,抑制率在5.33%~43.33%和10.81%~46.85%之间,对高羊茅地上部分的化感抑制作用大于地下部分。刺柏叶水提液中鉴定出31种化合物,主要成分有7-羟基香豆素、香草醛、2,4-二叔丁基苯酚、邻苯二酚、2,3-二氢苯并呋喃、4-羟基-3-甲基苯乙酮等。