大花卷丹的组织培养及限制生长保存

离体保存是植物种质保存的重要手段之一,为实现对大花卷丹的保护性利用,本文对其组织培养体系及限制生长离体保存技术进行了研究。结果表明,在常温（23±2）℃、光照强度约为40μmol.m-2.s-1、光照时间14h.d-1的条件下,大花卷丹鳞片在MS＋6-BA1.0mg.L-1＋NAA0.2mg.L-1培养基中生长情况较好,能直接诱导芽,且小鳞茎的生长速度较快。将诱导出的小鳞茎切割后,接种到1/2MS＋NAA0.5mg.L-1＋活性炭2g.L-1生根培养基2～3周即能生根,生长状况良好。提高MS培养基中蔗糖达90和110g.L-1时可以抑制其生长,能够保存大花卷丹试管苗10个月,保存过程中生长正常,株高生长缓慢,但根长势较快。在蔗糖浓度90g.L-1基础上再添加30g.L-1甘露醇的培养基能进一步抑制试管苗根的生长。6个月后,转移到正常培养基上培养均能恢复生长,其鳞片在诱导培养基上能正常分化。因此,采用大花卷丹鳞片组织培养可以形成种苗,在培养基中添加高蔗糖浓度和甘露醇可以使其试管苗保存1年以上。     

过路黄自然三倍体的发现

过路黄为报春花科的多年生匍匐草本植物,是有名的中药材,也是十分优质的园林地被植物。该文报道了过路黄的自然三倍体,以期为过路黄的开发利用提供新的参考资料。该研究先将湖北省武汉狮子山和黄石月亮山的过路黄居群引种至同一实验地进行栽培,然后观测其植株形态和叶片气孔大小,并利用常规压片法进行细胞染色体的计数与核型分析。结果表明:源自黄石月亮山的过路黄的叶片长度、叶片宽度、叶片面积、花瓣长度、花瓣宽度、花瓣面积及叶背气孔面积均显著高于源自武汉狮子山的过路黄;黄石月亮山的过路黄核型公式为3n=36=3m+3sm+6st+24t,与武汉狮子山的过路黄核型2n=24=2m+2sm+4st+16t不同。基于上述形态与核型数据,该文认为黄石月亮山的过路黄居群为自然三倍体。过路黄自然三倍体的发现丰富了过路黄的多倍体资料,不仅能为过路黄的遗传多样性及进化研究提供参考,还能为过路黄的药用、园林应用及其新品种的培育提供优良材料。     

Genetic diversity in fragmented populations of Berchemiella wilsonii var. pubipetiolata (Rhamnaceae)

BACKGROUD AND AIMS: Berchemiella wilsonii var. pubipetiolata (Rhamnaceae) is distributed in fragmented habitat patches in eastern China. It is highly endangered because of severe disturbance by anthropogenic activities. Information on genetic variation and structure is critical for developing successful conservation strategies for this species. METHODS: Allozyme variation of population genetic diversity and structure was investigated for a total of 98 individuals sampled from four extant populations using isoelectric focusing in thin-layer polyacrylamide slab gels. KEY RESULTS: Based on 20 loci scored from the nine enzymes examined, a high genetic diversity was detected at both the species and population level, while there was a loss of low frequency alleles (<0.1) in all populations. Most loci showed deviation from Hardy-Weinberg equilibrium due to excess of heterozygotes in all populations, suggesting that selection for heterozygotes has occurred in this species. The genetic diversity was mainly found within populations with a moderate genetic differentiation (F(ST) = 0.13), but the two geographically discontinuous population groups showed significant differences, with F-statistic values of 0.078 for the Zhejiang populations and 0.014 for the Anhui populations, respectively. CONCLUSIONS: It appears most likely that this species has experienced a recent decrease in population size, and genetic drift in small populations has resulted in a loss of alleles occurring at low frequency. The differentiation into two population groups reflects a population genetic consequence that has been influenced by the different land-use in the two regions. Some conservation concerns are discussed together with possible strategies for implementing in situ and ex situ conservation.     

The development of dormancy in bulblets of Lilium speciosum generated in vitro. II. The effect of temperature

Upon harvest, lily ( Lilium speciosum Thunb. cv. Rubrum) bulblets generated in vitro under standard conditions (11 weeks at 20°C) were dormant and needed a cold treatment prior to planting. During culture in vitro at 20°C, the bulblets proceeded through three phases: (1) at first they were non–viable and non-dormant (up to 5 weeks), (2) then viable and non-dormant (5–9 weeks) and (3) finally viable and dormant (from 9 weeks onwards). At 15°C, the bulblets became viable but did not develop dormancy, even after protracted culture. The results suggest that the development of dormancy depends upon an accumulation of'heat units'occurring at temperatures higher than 15°0. At 25°C, the succession of the three phases occurred more rapidly than at 20°C and heat units were accumulated more rapidly. During the third period, the chilling requirement increased showing that heat units continued to be accumulated during this period.
Dormancy connotes an arrest of growth. In lily bulblets, however, the number of scales continued to increase after the induction of dormancy at 20 or 25°C. Many of the scales initiated before the onset of dormancy were formed by swelling of a petiole, whereas, after the onset of dormancy, all scales were formed directly from a primordium. We conclude that the development of dormancy corresponds to a switch in the development of the primordium. Thus, after the induction of dormancy the primordium lost the ability to become a leaf and always developed into a scale.     

湿地植物大花百合种群的性系统特征

开花植物性系统特征是植物在长期适应进化过程中逐渐形成的繁殖策略, 它在一定程度上影响了物种的种群结构及其在生境中的分布格局, 因此性系统特征一直是植物进化与生态学领域的研究热点。本研究于2012年和2020年在吉林省金川泥炭沼泽湿地, 通过样地调查取样的方法, 研究了湿地植物大花百合(Lilium concolor var. megalanthum)的性系统特征以及不同性别表型植株的比例、密度及空间分布格局, 并探究了大花百合植株个体大小和其性别表达的联系, 比较了不同性别表型的花粉实际可育性和来源不同的花粉授粉处理结实后的种子活力。结果显示, 个体水平上, 大花百合具有雄花植株、两性花植株和雄花两性花同株(即雄全同株) 3种性表型; 种群水平上, 具有雄花的个体充当父本, 通过花粉向下一代传递基因, 而具有两性花的个体主要充当母本, 通过胚珠实现基因的传递。2020年大花百合雄花植株占种群内开花植株的39.14%, 相比2012年雄花植株比例增加了22.80%; 大花百合种群分布密度为0.06株/m², 较2012年下降了0.09株/m²。从2012年到2020年, 总体表现为种群密度降低, 雄花植株相对比例增加的趋势。两性花植株和雄花植株在小尺度范围主要呈聚集分布, 随着尺度增大, 趋于随机分布。雄花植株显著小于两性花植株, 但鳞茎资源分配显著高于两性花植株。大花百合植株的性表达遵循大小依赖的性分配假说: 个体较小的植株表达为雄花植株, 而个体较大的植株则为两性花植株或雄全同株。在不同授粉处理下的结籽率和种子萌发结果表明, 大花百合自花授粉结籽率和坐果率显著低于异花授粉, 雄花植株和两性花植株花粉可育性以及对两性花植株授粉后所获得种子活力无显著差异。大花百合雄花植株的出现可能是对有限环境资源条件适应的结果, 反映了湿地条件下该植物在生长和繁殖资源之间的权衡策略, 在长期的湿地演变过程中, 这种性系统特征的出现具有一定的适应性意义。     

Dendritic cell populations in colon and mesenteric lymph nodes of patients with Crohn's disease.

Dendritic cells (DCs) are key cells in innate and adaptive immune responses that determine the pathophysiology of Crohn's disease. Intestinal DCs migrate from the mucosa into mesenteric lymph nodes (MLNs). A number of different markers are described to define the DC populations. In this study we have identified the phenotype and localization of intestinal and MLN DCs in patients with Crohn's disease and non-IBD patients based on these markers. We used immunohistochemistry to demonstrate that all markers (S-100, CD83, DC-SIGN, BDCA1-4, and CD1a) showed a different staining pattern varying from localization in T-cell areas of lymph follicles around blood vessels or single cells in the lamina propria and in the MLN in the medullary cords and in the subcapsular sinuses around blood vessels and in the T-cell areas. In conclusion, all different DC markers give variable staining patterns so there is no marker for the DC.     

太白山锐齿栎林物种-多度分布格局

以太白山1.5 hm2的锐齿栎原始林和次生林样地中环境因子和胸径≥1 cm的木本植物调查数据为基础,采用统计模型(对数正态模型)、生态位模型(Zipf模型、断棍模型、生态位优先模型)和中性模型,拟合了锐齿栎群落的物种多度分布.结果表明:太白山锐齿栎林物种多度分布格局受到生境异质性的影响.其中,地形因子对原始林物种分布影...     

Distribution of Lilian's Lovebirds in Malawi

Lilian's Lovebird Agapornis lilianae is regarded as a mopane Colophospermum mopane woodland specialist. Its global population is sparse and is spread along the Zambezi valley with little known about its current distribution and status. We explored the current distribution of Lilian's Lovebird in Malawi, and in particular focused on the distribution and habitat associations of the largest resident population in Liwonde National Park (LNP). Local birders and tourist guides provided distribution information from across Malawi. Transect walks were conducted to collect data in LNP. Five new atlas records are reported; three were within 40–56 km of the LNP population and two were over 150 km south and north of LNP, respectively. One of the sites is about 66 km from the Lilian's Lovebird population in Luangwa Valley, Zambia. New national records were evidence of the importance of seasonal movements to the species. Lilian's Lovebirds occurred throughout LNP with the highest abundance in the central section. Seasonal movements to areas outside the park were also recorded. A variety of vegetation types were used by the lovebirds, but the strongest habitat associations were with seasonally wet grasslands and not mopane woodlands as would be expected. Thus, conservation efforts should also include these other habitats.     

秦岭皇冠优势灌木苦糖果的空间分布格局及种内种间关联

以秦岭皇冠暖温性落叶阔叶林25 hm²森林样地中的优势灌木苦糖果为对象,研究了苦糖果不同径级个体的空间分布格局以及种内种间关系。结果表明: 苦糖果径级结构呈现出下宽上窄的金字塔型,小径级植株数量最多,更新状态较好,处于稳定增长阶段,有利于群落更新和演替。以Ripley's K函数为基础,采用单变量和双变量成对相关函数,在3个零模型(完全空间随机模型、异质泊松模型和先决条件模型)的处理下,树种整体和不同径级以聚集分布为主,且聚集程度随研究尺度的加大而逐渐减小,逐渐趋向随机分布。受到生境异质性、扩散限制、负密度制约等影响,种内不同径级个体之间以正关联为主,但也有一定程度的无关联,未出现负关联的情况。种间关系较为复杂,既有无关联,也有正关联和负关联,但以负关联和无关联为主。     

兰州百合小孢子母细胞减数分裂异常现象的观察

对兰州百合(Lilium davidii var.unicolor)小孢子母细胞减数分裂异常进行了研究,发现存在不等二价体、同源染色体早分离、染色体桥、不均等分离、滞后染色体、核外染色体、微核等。分析了这些异常形成的可能机制及对正常小孢子形成的影响。人工花粉萌发实验表明：小孢子母细胞减数分裂异常是导致花粉败育的主要原因。认为兰州百合长期行无性繁殖引起染色体结构变异,导致减数分裂异常。     

Dynamics and viability analysis of transplanted and natural lady's slipper (Cypripedium japonicum) populations under habitat management in South Korea

To assess the effectiveness of conservation‐based transplantation of the endangered orchid (Cypripedium japonicum), we compared the morphology, physiology, stem‐count change, and population viability of natural versus transplanted populations undergoing habitat management (repeated removal of competing understory vegetation) between 2009 and 2015 in South Korea. The restored site had lower transmitted light and soil humidity than the natural site. The natural and transplanted populations differed in leaf morphology and total chlorophyll content (natural: 1.00 ± 0.04, restored: 0.53 ± 0.06). No recruitment occurred during the monitoring period. Population viability tended to decrease in the restored population (λ_G = 0.97, μ = ?0.05, σ² = 0.036) and increase in the natural population (λ_G = 1.07, μ = 0.03, σ² = 0.075). The repeated removal of competing understory vegetation had different effects on leaf traits, abundance, and reproductive properties of the endangered orchids in both populations. Notably, habitat management increased the stem count and flowering rate in natural C. japonicum but did not increase the fruit‐setting rate. Thus, despite repeated habitat management efforts (removal of competing understory vegetation), we conclude that the population viability of transplanted populations of the endangered orchid C. japonicum had poor long‐term viability compared with naturally occurring populations, a difference that is mainly attributed to inappropriate transplant‐site selection.     

Ultrastructural aspects of storage lipid mobilization in the tapetum of Lilium hybrida var. enchantment

Stages in the formation and degradation of pollenkitt in the anther of Lilium have been investigated using the electron microscope. This material, which appears to be a complex of lipid and carotenoids, is formed during the autolysis of the tapetal cells by the fusion of lipidic inclusions with globules derived from plastids. Autolysis of the tapetal cells is progressive for it commences with the disintegration of many cytoplasmic components, followed by the breakdown of storage lipids. The plasma membrane maintains its integrity during these events apparently, by proliferation, aiding in the transfer of the products of hydrolysis into the loculus. During the course of lipid breakdown, a striking vacuolar system is formed in the tapetal cytoplasm, presumably containing the products of this hydrolysis. The source of membranes for this system is clearly the lipid globules themselves. The generation of the membrane apparently involves the participation of electronopaque material, possibly enzymic, contained within the lipid globules.     

Breakdown of gametophytic self-incompatibility in subdivided populations

In many hermaphroditic flowering plants, self-fertilization is prevented by self-incompatibility (SI), often controlled by a single locus, the S-locus. In single isolated populations, the maintenance of SI depends chiefly on inbreeding depression and the number of SI alleles at the S-locus. In subdivided populations, however, population subdivision has complicated effects on both the number of SI alleles and the level of inbreeding depression, rendering the maintenance of SI difficult to predict. Here, we explore the conditions for the invasion of a self-compatible mutant in a structured population. We find that the maintenance of SI is strongly compromised when a population becomes subdivided. We show that this effect is mainly caused by the decrease in the local diversity of SI alleles rather than by a change in the dynamics of inbreeding depression. Strikingly, we also find that the diversity of SI alleles at the whole population level is a poor predictor of the maintenance of SI. We discuss the implications of our results for the interpretation of empirical data on the loss of SI in natural populations.     

Natural hybridisation in birch: triploid hybrids between Betula nana and B. pubescens

Hybridisation between diploid (2n=28) dwarf birch Betula nana L. and tetraploid (2n=56) downy birch B. pubescens Ehrh. has occurred in natural populations in Iceland. About 10% of birch plants randomly collected are triploid (2n=42) hybrids. Ribosomal gene mapping on chromosomes and genomic in situ hybridisation confirms the hybridity. However, the triploid hybrids are not morphologically distinct, i.e. they are not different from diploid and tetraploid birch plants that have intermediate morphology. The triploid hybrids have evidently played an important role in driving bi-directional gene flow between these two species. This paper reviews the extent of interspecific hybridisation in selected birch woodland populations and discusses the significance of natural hybridisation and introgression in birch.     

Brief communication: When Adam delved. An activity-related lesion in three human skeletal populations

A rare, activity-related lesion, the clay-shoveller's fracture, was identified during osteological analysis in three human populations dating from the Roman to the later Medieval period in England, circa fourth to 14th centuries A.D. The prevalence of this fracture in these populations suggests an osteological indicator for several possible manual activities, but also one that may be the result of a long-standing human subsistence adaptation requiring digging in the soil. Since males as opposed to females appear to be preferentially affected, the occurrence of such injuries has the potential to provide an insight into the sexual division of labor in earlier human populations. © 1996 Wiley-Liss, Inc.     

Fitness-dependent mutation rates in finite populations

Mutation rate may be condition dependent, whereby individuals in poor condition, perhaps from high mutation load, have higher mutation rates than individuals in good condition. Agrawal (J. Evol. Biol.15, 2002, 1004) explored the basic properties of fitness-dependent mutation rate (FDMR) in infinite populations and reported some heuristic results for finite populations. The key parameter governing how infinite populations evolve under FDMR is the curvature (k) of the relationship between fitness and mutation rate. We extend Agrawal's analysis to finite populations and consider dominance and epistasis. In finite populations, the probability of long-term existence depends on k. In sexual populations, positive curvature leads to low equilibrium mutation rate, whereas negative curvature results in high mutation rate. In asexual populations, negative curvature results in rapid extinction via 'mutational meltdown', whereas positive curvature sometimes allows persistence. We speculate that fitness-dependent mutation rate may provide the conditions for genetic architecture to diverge between sexual and asexual taxa.     

兰州百合器官离体培养外植体位置效应观察

探讨兰州百合 (Liliumdavidiivar.unicolor)鳞茎鳞片、叶片和根的不同切段的培养效应。结果表明 :其切段不定芽的分化速度和数量是下段 >中段 >上段。芽的诱导和增殖的最适外植体为鳞茎鳞片 ,兰州百合离体培养中鳞片不定芽诱导和快速繁殖的培养基为MS BA2mg L NAA 0 2mg L ,增殖培养基与诱导培养基相同 ,3周左右不定芽开始分化。叶和根不同部位中不定芽的发育能力大体与鳞茎鳞片一致 ,但低于鳞片 ,较适宜的培养基为MS BA2mg L NAA 0 4mg L ,生根培养基为 1 2MS NAA 0 3mg L ,约 15d生根 ,生根率大于95 %。月增殖率为 1∶4 ,整个繁殖周期约需 3个月。     

Genetic variation in natural populations of Anthurium sinuatum and A. pentaphyllum var. pentaphyllum (Araceae) from north‐east Brazil using AFLP molecular markers

Genetic variation was investigated using AFLP markers in 12 populations of Anthurium sinuatum and A. pentaphyllum var. pentaphyllum (Araceae) in north‐east Brazil, Amazonia and the Brazilian Atlantic forest. Two unique genetic patterns characterized the populations of A. sinuatum as a group, but no correlation between genetic and geographical interpopulation distance was found; the Amazonian population was not separated from that in Ceará. The isolated Ceará brejo populations of A. sinuatum were genetically distinct, but genetic diversity levels were similar to populations elsewhere, with no evidence of genetic erosion. Anthurium pentaphyllum populations were significantly different from each other; Bayesian genetic structural analysis found no common genetic pattern, but revealed genetic clusters unique to subgroups and individual populations in the Atlantic forest and French Guiana. Anthurium pentaphyllum and A. sinuatum can be distinguished genetically, but individuals of both species formed intermediate genetic clusters that blurred their distinction. We suggest that genetic mixing of A. sinuatum and A. pentaphyllum has occurred in north‐east Brazil, possibly connected with cycles of humid forest expansion. The weak genetic structure in A. sinuatum is consistent with the natural fragmentation of continuous forest areas, possibly during the Holocene. This study highlights the scientific importance of the highly threatened brejo forests for tropical American biogeography. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 159 , 88–105.     

沙地樟子松天然分布与引种栽培

樟子松以其抗寒、抗旱和较速生等优良特性成为我国北方干旱、半干旱风沙区防护林和用材林造林的主要树种 ,但自 2 0世纪 90年代以来 ,沙地樟子松人工林出现了不同程度的衰退现象 ;更为严重的是目前我国樟子松人工造林仍在北方干旱、半干旱地区大面积推广 ,因此 ,探明沙地樟子松人工林产生衰退的原因 ,并更好地经营管理该树种人工林 ,对我国北方防护林/人工林建设具有重大意义。本文在广泛收集国内外有关樟子松研究结果的基础上 ,详述了樟子松在我国的天然分布概况 ,对沙地樟子松在引种栽培方面 ,即沙地樟子松的种源区划、种子品质的比较、种子的遗传特性及适应性等研究进展进行了综述 ,提出了在沙地樟子松引种栽培研究中亟待解决的一些问题和建议 ,对今后该树种沙地人工林经营研究具有参考价值。     

Estimation of effective population size in continuously distributed populations: there goes the neighborhood

Use of genetic methods to estimate effective population size (N_e) is rapidly increasing, but all approaches make simplifying assumptions unlikely to be met in real populations. In particular, all assume a single, unstructured population, and none has been evaluated for use with continuously distributed species. We simulated continuous populations with local mating structure, as envisioned by Wright''s concept of neighborhood size (NS), and evaluated performance of a single-sample estimator based on linkage disequilibrium (LD), which provides an estimate of the effective number of parents that produced the sample (N_b). Results illustrate the interacting effects of two phenomena, drift and mixture, that contribute to LD. Samples from areas equal to or smaller than a breeding window produced estimates close to the NS. As the sampling window increased in size to encompass multiple genetic neighborhoods, mixture LD from a two-locus Wahlund effect overwhelmed the reduction in drift LD from incorporating offspring from more parents. As a consequence, never approached the global N_e, even when the geographic scale of sampling was large. Results indicate that caution is needed in applying standard methods for estimating effective size to continuously distributed populations.