落叶松种间及无性系间ISSR鉴别技术的研究

采用ISSR分子标记技术对兴安、长白和日本落叶松种间以及不同无性系进行了鉴别。从49条引物中筛选出13条ISSR引物可以对落叶松种间和无性系间进行鉴别,特异条带个体的百分率为100%,该项技术为落叶松新品种以及良种的准确鉴别提供了新的途径和手段：其中5条引物在日本落叶松、兴安落叶松和长白落叶松不同位置扩增出特异谱带,作为种的鉴定的标准,有9条引物可以对落叶松种内不同无性系分别扩增出特异片段,进行无性系的鉴别。     

Natural regeneration patterns of the introduced larch, Larix kaempferi (Pinaceae), on the volcano Mount Koma, northern Japan

The 1929 eruption of Mount Koma (1140 m in altitude) completely deforested the vegetation on the summit area of the volcano. An alien species of larch, Larix kaempferi (=L. leptolepis) was planted on the lower slopes of the volcano between 1953 and 1963, but since then has become abundant on the summit. To determine the regeneration patterns of the larch, we measured stem densities on aerial photographs taken in 1963, 1973 and 1994, and in the field during 1996. Larix kaempferi stems with crown diameters > 2 m were mapped on aerial photographs divided into 1083 100 m×100 m grids. Stem densities on the summit increased from 0.8/ha in 1963, to 14.1/ha in 1994. Willows and birches also established there but did not grow as large as the larch. All these species are wind dispersed, and larch densities were higher in areas closer to the plantations, suggesting that wind intensity and direction determined seed migration. Four environmental factors—slope gradient, direction, elevation, and distance from the plantations in each grid—were correlated with larch stem densities. Multiple regression showed that establishment patterns of L. kaempferi in the early stages were mainly related to distance from seed source (the plantations). Later, geographical disturbances and/or physiological stresses became more important. Density effects on tree invasion have been weak until now. We concluded that revegetation primarily depends on the chance of seed immigration, and that the larches may be an earlier successional species than any other native tree species.     

Identification of larch species (Larix decidua, Larix kaempferi and Larix X eurolepis) and estimation of hybrid fraction in seed lots by RAPD fingerprints

Species-specific RAPD markers were used to identify the different larch species (Larix decidua and Larix kaempferi) and their interspecific hybrid (Larix X eurolepis). Although morphological differences between pure species and the hybrids exist, differentiation is not always possible, especially at an early stage (seed or plantlet). Eleven RAPD markers differentiated the two larch species, and 4 species-specific markers were sufficient to estimate the F₁ hybrid fraction in a seed lot. The species-specific markers were tested on individual trees of European and Japanese larches of diverse geographic origins and on several seed lots of different origins (F₁, F₂ hybrids and pure species). The 4 specific markers found for the European larch and the Japanese larch were monomorphic and present in all provenances and in all F₁ hybrid trees tested. Polymorphic SCAR fragments were obtained for 3 of the 11 fragments originally selected for the RAPD screening phase. For 2 of them, the sequence had some homology with the mitochondrial genome of other organisms and is thus mitochondrial. The two mitochondrial fragments and the OPF-13₁₀₀₀ fragment exhibited one polymorphic band, thereby maintaining its species-specific identity: OPF-13₁₀₀₀ is specific to the European larch. The 4 RAPD primers selected in this study offer a reliable, quick and cheap tool for the identification of different larch species (Larix decidua and Larix kaempferi) and their interspecific hybrid (Larix X eurolepis). Received: 28 February 1999 / Accepted: 29 April 1999     

外来树种日本落叶松和日本花柏对鄂西北森林群落的影响

【目的】研究大面积栽植外来树种日本落叶松和日本花柏对鄂西北森林群落物种多样性的影响,为评价外来树种的入侵风险提供依据。【方法】采用样地调查法对比研究外来树种日本落叶松和日本花柏人工林与当地森林群落特征差异。【结果】日本落叶松人工林样地林下植物种类丰富,样地平均物种数与当地天然林样地物种数相比无显著差异;林下灌木层和草本层多样性指数较高,草本层多样性指数与当地天然林相比无显著差异;林下未发现日本落叶松的更新苗。日本花柏人工林样地平均物种数显著少于当地其他人工林样地;乔木层、灌木层和草本层的4个多样性指数值均小于当地其他人工林样地;在3个样地中出现日本花柏更新苗,更新苗数量达479株·hm~(-2)。【结论】引种栽培日本落叶松不会导致当地森林群落的物种多样性降低,不会引起生物入侵风险;但引种栽培日本花柏会明显降低当地森林群落的物种多样性,对当地森林生态系统的稳定构成一定威胁。     

Species-diagnostic markers in <Emphasis Type="Italic">Larix</Emphasis> spp. based on RAPDs and nuclear,cpDNA, and mtDNA gene sequences,and their phylogenetic implications

Genetic markers from the nuclear, chloroplast, and mitochondrial genomes were developed to distinguish unambiguously among four larch species [Larix laricina (Du Roi) K. Koch, Larix decidua (Mill.), Larix kaempferi (Lamb.) Sarg., and Larix sibirica (Ledeb.)] used in intensive forestry in eastern North America. Nine random amplified polymorphic DNA (RAPD) fragments had good diagnostic value, and 3 out of 12 nuclear genes were found to harbor fixed interspecific polymorphisms implicating a total of 17 single nucleotide polymorphisms (SNPs) and 2 indels. The sequencing of five mtDNA introns (cox1-intron1, matR-intron1, nad1-intron b/c, nad3-intron1, and nad5-intron1) and four cpDNA regions (matK, trnL-intron, trnT–trnL and trnL–trnF intergenic spacers) resulted in the identification of 14 sites with fixed interspecific differences among the four species. Including the ten Larix species, one polymorphic site per 47 nucleotide sites sampled was observed for nuclear genes, one per 283 sites for cpDNA, and one per 374 sites for mtDNA. The phylogeny of the genus could be estimated from variation among the ten species detected in two cpDNA intergenic regions and four mtDNA introns. There was congruence between cpDNA and mtDNA phylogenies with three large groups delineated: the North American, North Eurasian, and South Asian taxa. The position of L. sibirica differed between organelle genomes. It was regrouped with South Asian species on the cpDNA tree, but with its North Eurasian congenerics on the mtDNA tree. To simplify the detection of diagnostic DNA sequence polymorphisms among the four main Larix species, cleaved amplified polymorphic sequence (CAPS) assays were developed from the polymorphisms identified in the various genomes. Seventeen primer–enzyme combinations were tested, and six were selected for their high level of informativeness. These new species-specific diagnostic markers should be useful for the certification of larch breeding materials and hybrid stocks used in intensive forestry in the northern hemisphere.     

Chromosomal mutations in Siberian larch (<Emphasis Type="Italic">Larix sibirica</Emphasis> Ledeb.) on Taimyr Peninsula

Chromosomal mutations were studied in the Norilsk population of Siberian larch (Larix sibirica Ledeb.) growing at the northeastern boundary of the species range affected by airborne smelter emissions. Different types of frequent chromosomal mutations have been revealed in the Norilsk population of L. sibirica and B-chromosomes have been found in this species for the first time.     

Seed-specific identification of Larix gmelinii,Larix olgensis,and Larix principis-rupprechtii using sequence-characterised amplified region markers

Larix gmelinii, Larix olgensis, and Larix principis-rupprechtii are the three native and sympatric larch species in North China, and each of these species has a distinctive ecological niche. It is difficult to identify them based only on certain morphological characters, particularly the seed appearance. In this study, the seed endosperms of these three larch species were analysed using the random amplified polymorphic DNA (RAPD) technique to screen for interspecific differences. The following three RAPD markers linked to species-specific segments were observed in the different species: 1475-bp (Larix gmelinii and L. olgensis), 505-bp (Larix principis-rupprechtii), and 1121-bp (Larix gmelinii) markers. The three seed-specific fragments amplified by the RAPD markers were sequenced, and the sequences were used to design and synthesise species-specific SCAR markers. The size of the SCAR fragments was concordant with that of the RAPD species-specific fragments. Therefore, these SCAR markers can be used to identify the seeds of different larch species, thereby providing a new molecular tool for the identification of larch seeds that leads to considerable savings in terms of time and economic resources.     

Influence of temperature on fractional composition of proteins and respiration of germinating seeds of Gmelin and Siberian larch

The influence of optimal and contrasting temperatures on the fractional composition of proteins and respiration of germinating seeds of Gmelin larch (Larix gmelinii (Rupr.) Rupr.) and Siberian larch (Larix sibirica Ledeb.) was revealed. The dominance of globulins (salt-soluble fraction) and insoluble proteins was noted in viable air-dry seeds of larch. Optimal and contrasting temperatures of germination of seeds caused significant changes in the content and dynamics of separate fractions of protein, the contrasting temperatures causing greater changes: increasing in the content of insoluble proteins, intense consumption of globulins at separate stages of germination. Respiration of the seeds during germination at contrasting temperatures also increased more than at an optimal temperature. Thermal regime of germination affected the character of relations between the respiration rate and contents of different protein fractions.     

Phenolic compounds of Siberian and Dahurian larch phloem

The paper presents results of the investigation of phenolic compounds of the bark of the Siberian larch (Larix sibirica Ledeb.) and the Dahurian larch (Larix gmelini (Rupr.) Rupr). The flavonoids, stilbenes, phenolic acids have been identified on the basis of chemical, chromatographic and spectral data. Quercetin-3-O-??-L-rhamnopyranoside has been found for the first time in the bark of the Larix genus. Phenolic compounds with pyrocatechol type of substitution of aromatic ring have been found to dominate in the phloem of the larch species considered.     

Investigation of physicochemical properties of arabinogalactan of different larch species

Samples of arabinogalactan (AG) were isolated by aqueous extraction from wood of different larch species (Larix sibirica Ledeb., Larix gmelinii (Rupr.) Rupr., Larix cajanderi Mayr., and Larix olgensis var. Koreana) and studied by HPLC, IR spectroscopy, and quantitative ¹³C NMR spectroscopy. The wood of the studied larch species was shown to contain significant amount of arabinogalactan (10–17% of the a.d.w. mass) and could be a source of its industrial production. The studied AG samples had similar structural and molecular-mass characteristics. This fact could facilitate the product standardization during its industrial production both from the wood of a single larch species and from mixed raw materials.     

赤杨对辽东落叶松人工林土壤氨基糖积累的影响

微生物残留物是土壤稳定性碳库的重要组成部分,然而其对固氮树种的响应还不清楚。以辽东山区日本落叶松(Larix kaempferi)人工纯林和落叶松-赤杨混交林为研究对象,以氨基糖作为微生物残留物的生物标识物,研究了赤杨对落叶松人工林根际和非根际土壤氨基糖积累的影响。结果表明,混交林中落叶松根际和非根际各氨基糖单体含量均显著高于纯林,说明赤杨引入有利于土壤微生物残留物的积累。其中,混交林落叶松根际及非根际土壤氨基糖葡萄糖含量分别比纯林高出99.5%(P0.01)和154%(P0.01);胞壁酸含量分别比纯林高出66.1%(P0.01)和132.3%(P0.01)。赤杨引入对氨基葡萄糖/胞壁酸比值的影响不显著,但显著增加氨基糖对土壤有机碳的贡献。冗余度分析表明全氮是驱动土壤中氨基糖发生变化的主要因子。表明赤杨引入显著提高微生物固持的土壤碳库和有机碳稳定性,这对落叶松人工林合理经营具有重要意义。     

Genetic relationships between European and Siberian larch,Larix spp. (Pinaceae), studied by allozymes. Is the Polish larch a hybrid between these two species?

Thirteen populations ofLarix decidua subsp.decidua and subsp.polonica, and three populations ofL. sibirica were investigated by starch-gel electrophoresis. In the populations assayed 61 alleles at 17 loci were revealed. The allozyme data support the earlier observations about close relationships between these two larch species. Nei's genetic distances betweenL. decidua andL. sibirica were relatively small (D = 0.057), however, almost five times larger, on average, than those between populations of the same species. Results obtained in this study disagree withBobrov's hypothesis about the hybrid origin of the Polish larch and suggest a direct origin from the European larch.     

Phylogenetic split of Larix: evidence from paternally inherited cpDNA trnT-trnF region

A molecular phylogeny of Larix comprising 12 species was constructed from the sequence analysis of the paternally inherited cpDNA trnT-trnF region of 46 individuals. The most parsimonious tree split Larix into three sister clades: one clade was composed of two North American species, the other two were short-bracted and long-bracted species of Eurasia respectively except that L. sibirica was clustered in the long-bracted clade. The difference between the present cpDNA phylogeny and previous nrDNA ITS phylogeny in the position of L. sibirica seems to suggest that ancient cytoplasmic gene flow might exist between sections Larix and Multiserialis. The short-bracted L. laricina and long-bracted L. occidentalis have an identical sequence of the trnT-trnF region, which implies that the bract length divergence among North American larches might have occurred recently or chloroplast capture happened during the early differentiation of the two species. The cpDNA results also shed some light on the biogeography of Larix.     

Larch chromosomal mosaicism

Karyological study of larch population members from different parts of the Larix olgensis L. Henry areal in the Primorskii krai has been carried out. The main amount of chromosomes for larch as n = 12 (2n = 24) has been confirmed. Mixoploidy was observed in all studied populations. The difference of individuals from the larch areal based on the cell amount with a different level of ploidity has been found in the population of L. olgensis locus classicus and both L. sibirica and L. gmelinii, which is probably a consequence of their hybrid nature.     

Effects of thinning and excluding deer browsing on sapling establishment and growth in larch plantations

Monoculture plantations with rapidly growing trees are often used for reforestation schemes on abandoned land. There is evidence that in some cases, reforestation facilitates forest succession toward natural species composition. However, the success of a scheme varies according to site conditions, and systematic investigations are required for adaptive management. Monoculture plantations were used to reforest abandoned pastures at the study site in Hokkaido, northern Japan. At the study site—a 40-year-old nonnative larch (Larix kaempferi) plantation—the effects of thinning and deer-browsing exclusion treatments on the demography of understory saplings were analyzed to achieve appropriate management planning for reforestation. After deer-browsing exclusion, saplings of various species became established, and species composition corresponded closely to that of a natural conifer–broadleaved mixed stand. Saplings of shade-tolerant species, such as Abies sachalinensis and Acer mono, were abundant. Thinning influenced the demography of saplings over an 8-year period and significantly affected the height growth rate of A. sachalinensis saplings, which show strong variations in response to varying light conditions. There were also negative effects of thinning, such as increased mortality and decreased height growth rate of broadleaved saplings, the growth of which was suppressed by facilitated growth of A. sachalinensis. Thus, treatments used for reforestation must take into account differences in demographic traits of tree species by including long-term monitoring.     

Induction of conifer immune responses by phytopathogenic fungus metabolites

The elicitor activity of compounds extracted from the mycelia of six species of phytopathogenic fungi was assessed from the sizes of necrotic lesions on the external surface of the living trunk phloem of five coniferous species inhabiting Siberia: Siberian larch (Larix sibirica L.), Scotch pine (Pinus sylvestris L.), Siberian spruce (Picea obovata Ledeb.), Siberian fir (Abies sibirica L.), and cedar pine (Pinus sibirica (Rupr.) Mayr.). The compounds for inoculation were extracted from the mycelium of ascomycetes imperfect, and basidium fungi; the living mycelia of these fungi were also used. The fungal extract or mycelium was placed into the hollows 7 mm in diameter in the trunk bark. Infection triggered the formation of hypersensitivity necrotic lesions in the inner bark exceeding in size those appeared after control wounding of four tree species (larch, pine, spruce, and cedar); fir was an exclusion. In experiments with tree trunks and conifer calluses, a dependence of immune response parameters (the sizes of necrotic lesions and the content of lignin and bound proanthocyanidins) on the quantity of the fungal preparation was elucidated. The largest necrotic lesions appeared after injection of 500μg of the fungal preparation into the hollow in the trunk, and its higher quantities did not increase the indices measured. The size of the necrotic lesion on the trunk bark is supposed to be used as a promising index characterizing the level of tree immunity and tolerance under various ecological conditions.     

长白落叶松、日本落叶松和兴安落叶松幼苗光合作用特性比较研究

研究长白落叶松(Larix olgensis Herry.),日本落叶松(Larix kaempferi Carr.) 和兴安落叶松(Larix gmelinii Rupr.)当年生和一年生幼苗的光合作用日变化、季节变化和光响应曲线,结果表明：①三种植物中,长白落叶松、日本落叶松当年生和一年生幼苗和兴安落叶松当年生幼苗光合速率日变化都呈双峰曲线,具有明显的“午休”特征。兴安落叶松一年生幼苗的光合速率日变化呈单峰曲线。②日本落叶松的光饱和点 (LSP) 最高,兴安落叶松光补偿点（LCP）最低。③三种落叶松的一年生幼苗都是在生长中期表现出最大的光合能力。从年龄来看,落叶松当年生幼苗在生长初期和生长中期的光合能力要低于一年生幼苗,但在生长后期高于一年生幼苗。④从种来看,生长初期,当年生和一年生幼苗的最大净光合速率(P_max)均为日本落叶松＞兴安落叶松＞长白落叶松;生长中期,当年生幼苗的P_max规律与生长初期相似,一年生幼苗的P_max为长白落叶松＞日本落叶松＞兴安落叶松;生长后期,当年生幼苗的P_max为长白落叶松＞兴安落叶松＞日本落叶松,一年生幼苗的P_max与生长中期一年生幼苗的规律正好相反。通过分析我们得到结论：三个树种在生长季节相同阶段具有不同的光合特性;每个种不同年龄和生长季节不同阶段也表现出不同的光合特性;三个树种中,长白落叶松幼苗对光抑制引起的光合器官损伤的修复能力最强,日本落叶松次之,兴安落叶松最弱;日本落叶松幼苗较喜光,光合作用能力较强,不易发生光抑制,而兴安落叶松幼苗较耐阴。因此在育苗和造林时应考虑不同树种的光合特性调节最佳的光照条件。     

Ice‐age persistence and genetic isolation of the disjunct distribution of larch in Alaska

Larix laricina (eastern larch, tamarack) is a transcontinental North American conifer with a prominent disjunction in the Yukon isolating the Alaskan distribution from the rest of its range. We investigate whether in situ persistence during the last glacial maximum (LGM) or long‐distance postglacial migration from south of the ice sheets resulted in the modern‐day Alaskan distribution. We analyzed variation in three chloroplast DNA regions of 840 trees from a total of 69 populations (24 new sampling sites situated on both sides of the Yukon range disjunction pooled with 45 populations from a published source) and conducted ensemble species distribution modeling (SDM) throughout Canada and United States to hindcast the potential range of L. laricina during the LGM. We uncovered the genetic signature of a long‐term isolation of larch populations in Alaska, identifying three endemic chlorotypes and low levels of genetic diversity. Range‐wide analysis across North America revealed the presence of a distinct Alaskan lineage. Postglacial gene flow across the Yukon divide was unidirectional, from Alaska toward previously glaciated Canadian regions, and with no evidence of immigration into Alaska. Hindcast SDM indicates one of the broadest areas of past climate suitability for L. laricina existed in central Alaska, suggesting possible in situ persistence of larch in Alaska during the LGM. Our results provide the first unambiguous evidence for the long‐term isolation of L. laricina in Alaska that extends beyond the last glacial period and into the present interglacial period. The lack of gene flow into Alaska along with the overall probability of larch occurrence in Alaska being currently lower than during the LGM suggests that modern‐day Alaskan larch populations are isolated climate relicts of broader glacial distributions, and so are particularly vulnerable to current warming trends.     

Heartwood extractives and lignin content of different larch species (<Emphasis Type="Italic">Larix </Emphasis>sp.) and relationships to brown-rot decay-resistance

The extractive content of lignin and the brown-rot decay-resistance against Coniophora puteana and Poria placenta were studied in larch heartwood from different species and origin (Larix decidua var. decidua, L. decidua var. sudetica, L. kaempferi , L. × eurolepis). The study material consisted of 106 trees from a 39-year old provenance trial in France. The hot-water-soluble extractives were very variable (from5.66% to 20.50% of dry weight), but there was no significant variation between the investigated species and origins. In contrast, acetone extractives, the total amount of phenolics and lignin showed significant differences. The concentration of phenolics and lignin was significantly higher in L. kaempferi and in L. × eurolepis than in L. decidua. The total phenolics content was strongly correlated with decay-resistance in all investigated larch origins. A higher concentration of phenolics goes hand in hand with higher decay resistance and phenolics might therefore be a promising parameter to rapidly evaluate the level of decay-resistance in larch.     

卧龙自然保护区落叶松林不同恢复阶段的嗜尸性甲虫物种多样性

在四川卧龙国家自然保护区,以天然落叶阔叶林（约100年生）为对照,选择新种植（5年生）、幼年（15年生）和成熟（45年生）的3种落叶松种植林,采用引诱法分别在地表和地上1.5 m处取样,研究处于不同恢复阶段林地中的嗜尸性甲虫物种多样性及其变化格局。共采集甲虫标本3 066号,其中隐翅虫、球蕈甲和埋葬甲科分别占总个体数的43.71%、31.83%和17.97%。嗜尸性甲虫的多度格局呈对数正态分布,随着落叶松林树龄的增长,其分布格局更加接近天然林。物种丰富度和多样性在3种落叶松林内均显著低于天然林,且在3种落叶松林中,新种植的最低。主坐标分析排序和聚类分析表明,不同树龄的落叶松林和天然阔叶林间的嗜尸性甲虫群落组成存在显著差异。以上结果表明,落叶松种植林尚无法取代天然落叶阔叶林在维持嗜尸性甲虫物种多样性中的作用。