基于高通量测序的3种竹子小枝真菌群落

为了解感染丛枝病时竹子真菌群落的特征,以丛枝病侵染的斑竹(Phyllostachys bambusoides f. lacrima-deae)、毛竹(Ph. edulis)和早竹(Ph. praecox)小枝为研究材料,运用高通量测序技术、DNA条码技术和生物信息学技术,分析了感染丛枝病的斑竹、毛竹、早竹真菌群落的物种组成和多样性,探讨了竹子丛枝病病原菌与其他竹子真菌之间的相关性。结果表明:(1) 3种竹子小枝共鉴定到706个最终的OTUs,所有样品中均存在的有48个; 3种感病竹子真菌群落中相对丰度较高的菌群包括:针孢麦角菌属(Aciculosporium)、竹黄属(Shiraia)、漆斑菌属(Myrothecium)、棘壳孢属(Pyrenochaeta)、刺盘孢/炭疽菌属(Colletotrichum)、镰刀菌属(Fusarium)、弯梗孢属(Camptophora)和假酵母状菌属(Pseudozyma)。(2)3种感病竹子真菌群落间的Chao1指数和Shannon指数差异不显著(P0.05)。(3) 3种感病竹子的病原菌为竹针孢座囊菌(Aciculosporium take),该菌与13种竹子真菌之间存在负相关,其中9种的相关性达到显著水平(P0.05);该菌与2种竹子真菌之间存在较弱的正相关。(4)鉴定的竹子真菌中存在绿色木霉(Trichoderma virens)、枝孢霉属真菌(Cladosporium sp.)、竹黄属真菌(Shiraia sp.)、弯孢霉属真菌(Curvularia sp.)、青霉属真菌(Penicillium sp.)和枝顶孢属真菌(Acremonium sp.),这些真菌是竹子病害潜在的生防菌。     

竹子扩张生态学研究:过程、后效与机制

竹子是竹亚科植物的总称,在人类文化与经济活动中扮演着重要角色,然而竹子也会向其邻近的生态系统不断入侵扩张,引发一系列生态环境问题。该综述试图从竹子扩张过程、扩张后效、扩张机制等方面,总结竹子扩张生态学方面取得的研究进展,以期为生态系统保护提供参考。综述认为:(1)竹子扩张过程主要包括地下渗透、地上成竹、竞争排斥和优势维持4个阶段;(2)竹子扩张不同程度地会影响邻近生态系统的群落组成与结构、生物多样性、土壤性质、生态过程与功能,并造成生态景观的破坏;(3)竹子扩张既与其生长快速、繁殖力强、形态多样、集团协同等内禀优势有关,也与邻近生态系统可入侵性有关;竹子可通过遮光、机械损伤、凋落物抑制、养分竞争与化感作用等直接或间接的竞争方式排斥其他植物,且自然或人类干扰有利于竹子扩张。因此,竹子扩张机制符合"内禀优势-资源机遇-干扰促进"的生物入侵假说。建议在未来环境变化背景下,加强竹子对环境变化的响应与适应、竹林-阔(针)叶林界面特征、竹子扩张过程与格局、扩张生态效应评价、竹子扩张防控与合理利用等领域的研究。     

竹子生态化学计量学研究:从生物学基础到竹林培育学应用

竹子生态经营与养分管理需要一个系统化的理论做指导。该文试以多重元素含量及比率为线索,归纳近年竹子生物学、生态学、培育学等领域的研究成果,以期形成竹子生态化学计量学,为竹林可持续发展提供有力支持。综述认为:(1)竹子具有独特的化学计量内平衡特征,其叶片C:N:P平均值为380:16:1;(2)竹子器官、年龄、发育阶段等内在因素和土壤、气候、采伐等外部环境都会影响竹子化学计量内平衡;(3)竹子生态化学计量变化会影响开花结实、发笋成竹、养分吸收、光合作用、克隆扩张、群落发展等生理生态学过程,也影响到竹材(笋)数量与品质的形成;(4)生态化学计量学原理已初步用于指导竹林养分诊断、平衡施肥和优质高产培育等生产实践。可见竹子生态化学计量学可将竹子生物特性、生态过程和生产经营紧密联系起来,然而这方面的工作才刚开始,建议今后应加强多竹种多重元素内平衡维持机制、竹材(笋)品质形成原理、竹子-土壤互作过程、养分诊断与平衡施肥、竹林生态系统养分优化管理等方面的研究,以促进竹林生产和环境保护。     

四川栗子坪自然保护区夏季大熊猫食性与主食竹生物量的关系

<正>竹子是大熊猫(Ailuropoda melanoleuca)的主要食物,是大熊猫赖以生存的物质基础(胡锦矗等,1985;胡锦矗,2001)。竹子生物量对大熊猫觅食乃至生存、繁衍等具有至关重要的影响。然而,竹子生物量随竹子种类、竹株部位和龄级以及生长环境的不同而可能具有明显差异(胡锦矗,1981;魏辅文等,1996)。截止目前,田星群(1989)等对秦岭大熊猫分布区的竹类资源进行了调查,黄华梨和杨飞虞(1990)、胡杰等(2000)分别对岷山山系大熊猫栖息地内竹子种类、主食竹     

相岭山系大、小熊猫主食竹类峨热竹的生长发育与环境因子间的相互关系

1994～1996年,在相岭山系冕宁县治勒自然保护区设点,对大熊猫和小熊猫主食竹类峨热竹与其它环境生态因子间的相互关系进行了长达3a的研究。研究结果表明,峨热竹的生长发育与环境生态因子如海拔、郁闭度、坡度和坡向之间有极其显著的相关关系,环境因子对其株高、基径、密度、发笋率、老笋比例和成竹死亡率等有较大的影响。随海拔高度的增加,竹子变矮变细,老笋比例下降;上层乔木郁闭度增加,竹子变稀,发笋率、老笋比例和成竹死亡率均降低。坡度增大,竹子变稀并且细而矮。阳坡的竹子率发笋高于阴坡。     

危害竹子的飞虱类昆虫区系及生物地理学初探(半翅目,蜡蝉总科,飞虱科)

对世界取食、危害竹子的飞虱类昆虫的物种多样性、区系成分和分布特点进行了统计、分析,并对该类昆虫的分布格局及可能的起源与演化路径进行了初步研究。结果表明:截至目前全世界共记录竹子飞虱20属105种,均隶属于飞虱亚科,以凹距飞虱族为优势类群,有18属95种,分别占竹子飞虱属、种数的90%和90.5%,余下的为飞虱族的类群;竹子飞虱主要分布于东洋界(16属96种,占91.4%)和新热带界(6属13种,占12.4%),少数属种可渗透分布至古北界;竹子飞虱的特有属、种极为丰富,特有属13个,占竹子飞虱总属数的65%,特有种89个,比例高达84.8%;竹子飞虱可能起源于新生代第三纪的冈瓦纳古陆,东洋界的中国南部和南亚诸岛是竹子飞虱的现代分布和分化中心,新热带界的厄瓜多尔可能是竹子飞虱的又一现代分布和分化中心。     

竹果胚体类型及其系统分类

报道了１３种竹果的胚体解剖特征,讨论了这些特征在系统分类上的意义。实验证明,竹果胚体的解剖式样是复杂多样的,从而认为,过去把竹亚科的胚型限定为竹型胚,即Ｆ＋ＰＰ型有很大的片面性。竹子的胚型除了与系统分类有一定关系外,还可能与竹子果实类型有关,又可能受其生活环境条件的制约。此外,根据实验,我们发现国内外学者尚未研究的竹胚的某些其它特征,且这些特征与竹子的系统分类也有一定关系,例如,胚体的弯曲程度,胚芽与盾片和胚根与盾片所成角度,中胚轴延伸情况、盾片大小和形状（纵切面观）等,这些特征对于同一种竹子是比较稳定的,而对于不同竹种和不同竹子类群来说总是存在着或多或少的差异。     

高通量测序技术及其应用

高通量测序技术是DNA测序发展历程的一个里程碑,它为现代生命科学研究提供了前所未有的机遇。详细介绍了以454、Solexa和SOLiD为代表的第二代高通量测序技术,以HeliScope TIRM和Pacific Biosciences SMRT为代表的单分子测序技术,以及最近Life Science公司推出的Ion Personal Genome Machine (PGM)测序技术等高通量测序技术的最新进展。在此基础上,阐述了高通量测序技术在基因组测序、转录组测序、基因表达调控、转录因子结合位点的检测以及甲基化等研究领域的应用。最后,讨论了高通量测序技术在成本和后续数据分析等方面存在的问题及其未来的发展前景。     

高通量测序技术在转座子研究中的应用

高通量测序技术极大地提高了测序效率,大幅度降低了测序成本,同时该技术具有特异性好、灵敏度高、精确性高等优势,目前已被广泛应用于遗传变异、转录组学和表观组学等研究。近年来,高通量测序技术也逐渐应用于转座子的研究,并取得了丰硕的成果。本文主要综述了高通量测序技术在转座子研究中的应用,包括转座子含量估算、靶点偏好性及分布、多态性及群体频率、稀有转座子的鉴定、转座子的水平转移以及转座子标签技术中的应用等,并简要介绍了目前研究中采用的主要测序策略和算法,及其存在的利弊和相应的解决方案。最后对高通量测序技术,尤其是第三代测序技术的发展趋势和它们在转座子未来的研究中的应用进行了展望,以期为相关的科研人员提供一个全面的了解和参考。     

新一代测序技术在临床检测中的应用

新一代测序技术在问世不到十年的时间里,大大推动了基因组学研究的发展。新一代测序技术因其高通量、快速、单碱基成本低等特点,自问世以来便广泛应用于生物学基础研究中。近年来,随着各种新测序平台和技术的成熟以及对基因组知识的积累,新一代测序技术在分子检测、临床诊断等应用研究领域也开始崭露头角。本文简要综述了新一代测序技术平台以及在肿瘤、遗传病、复杂性疾病等检测和诊断中的应用和前景。     

四种竹子的花器官形态描述

近几年来南京林业大学竹种园中4种竹子出现开花现象.首次描述了鹅毛竹(Shibaoea chinensis)和异叶苦竹(Arundinaria simonii f.heterophylla)的花部形态特征,补充描述了月月竹(Chimonobambusa sichuanensis)和福建茶秆竹(Arundinaria amabilis var.convexa)的花部形态特征.     

Ecological consequences of a massive flowering event of bamboo (Chusquea culeou) in a temperate forest of Patagonia,Argentina

Question: What changes occur as a consequence of the massive flowering and senescence of the dominant understory species of bamboo, Chusquea culeou (E. Desvaux)? In this study, we documented some of the ecological consequences of this rare event that occurred in 2001, the previous flowering having occurred more than 60 years ago. Location: Nothofagus temperate forest, Patagonia, Argentina. Methods: We assessed changes in environmental variables and bamboo biomass post‐flowering in an old‐growth southern beech forest. In addition, we monitored the demography of emergent Ch. culeou seedling and Nothofagus nervosa saplings, comparing non‐flowered (live understory) and flowered (senescent understory) patches within the forest matrix. Results: Bamboo flowering dramatically increased light availability in the forest understory but, surprisingly, other environmental changes were not observed. Bamboo seedlings emerged in both patch types, and experienced gradual but modest mortality through time. Bamboo dieback promoted higher survivorship and an increment in biomass, height, number of leaves and buds in the saplings of Nothofagus nervosa. Conclusion: The high density of bamboo seedlings 5 years after the flowering event and the independence of emergence from environmental variables suggest that understory regeneration is a gradual process that is not strongly regulated by initial seedling density or resource limitation. In contrast, microenvironmental conditions created after the flowering event significantly increased Nothofagus sapling growth and survival. These results suggest that overstory forest regeneration could be enhanced in this temperate forest in the first years after this infrequent bamboo flowering event.     

Research on ecological stoichiometry in bamboos: From biological basis to applications in silviculture of bamboo forests

Bamboo ecology and nutrient management require guidance of a set of theoretical principles. By focusing on the contents of multiple nutrient elements and their ratios and summarizing recent research findings in biology, ecology and silvics of bamboos, this paper seeks to establish the bamboo ecological stoichiometry (BES) in order to support the sustainable development of bamboo forests. It is considered that: (1) bamboos have the ubiquitous characteristics of stoichiometry, with average leaf C:N:P of 380:16:1, which complies to the “homeostasis hypothesis”; (2) the internal factors such as organs, ages and development stages and the external factors such as soil, climate and harvest can all affect the characteristics of bamboo stoichiometry; (3) changes in the ecological stoichiometry of bamboos affect the bamboo biological and ecological processes including photosynthesis, nutrients uptakes, flowering, shootings and growth, community dynamics, and qualities of bamboo products; (4) the principles of BES have been preliminarily used to guide the nutrient diagnosis, balanced fertilization, and production of high-quality and high-yield bamboos. As a new tool, BES can be further improved to integrate biology and silviculture under the background of ecological and environmental protection and food safety. Future research should place more emphasis on elucidating the ecological homeostatic mechanisms for more bamboos, as well as on understanding the stoichiometric principles in producing high-quality bamboo shoots, the bamboo-soil stoichiometric interaction processes, the nutrient diagnosis and stoichiometric balanced fertilization, and the optimal ecosystem management of bamboo forests.     

岷山北部竹类开花状况及对大熊猫的影响调查

2006年12月、2007年7～8月对岷山北部4县的竹类开花及大熊猫活动情况进行了调查.结果表明:(1)该区域竹种单一,仅有华西箭竹Fargesia nitida和缺苞箭竹F.denudata两种竹类,其中华西箭竹的分布面积最大;(2)该区域竹类从2004年开始出现开花现象,到2007年调查时开花过程已基本结束,开花竹面积达73 082 hm2,占竹类分布面积的51.36%;(3)在整个开花过程中,大熊猫实体被发现的频次增加,没有发现病、饿、死大熊猫的个体,现有大熊猫分布在竹类未开花的迭部县东部和舟曲县境内.此次竹类开花枯死,使该区域原有的大面积的大熊猫栖息地消失,因此需要加强对栖息地的保护和研究工作,使之尽快恢复成为大熊猫适合的栖息地.     

Bamboo germplasm screening with nuclear restriction fragment length polymorphisms

Summary Bamboo species are difficult to identify because flowering material is seldom available and taxonomy is of necessity based on vegetative characters. To evaluate the utility of restriction fragment length polymorphism (RFLP) analysis in bamboo systematics and germplasm screening, a library of random genomic probes from a Phyllostachys nigra PstI library was constructed. Probes from the library were used to screen bamboo germplasm consisting mostly of temperate bamboos of the genus Phyllostachys. RFLP variation was abundant, and species-specific patterns were readily obtained. Chloroplast DNA showed little variation among the bamboo accessions analyzed.     

Development of an efficient expression system with large cargo capacity for interrogation of gene function in bamboo based on bamboo mosaic virus

Bamboo is one of the fastest growing plants among monocotyledonous species and is grown extensively in subtropical regions.Although bamboo has high economic value and produces much biomass quickly,gene functional research is hindered by the low efficiency of genetic transformation in this species.We therefore explored the potential of a bamboo mosaic virus(BaMV)-mediated expression system to investigate genotype-phenotype associations.We determined that the sites between the triple gene block pr...     

Flowering cycles of woody bamboos native to southern South America

Neotropical woody bamboos range from northern Mexico to southern Argentina and Chile. The most interesting aspect of bamboo biology is their flowering habit. The species that are the most intriguing are those that manifest a cyclic pattern of gregarious flowering after long vegetative periods. The flowering cycle has been described in very few species. The goal was to identify mass flowering events of woody bamboo species native to Argentina and neighboring areas, and to estimate the flowering cycle of each species. Sixteen species were surveyed: Chusquea culeou, C. deficiens, C. lorentziana, C. montana, C. quila, C. ramosissima, C. tenella, C. valdiviensis; Colanthelia rhizantha; Guadua chacoensis, G. paraguayana, G. trinii; Merostachys clausenii, M. multiramea, Rhipidocladum neumannii and R. racemiflorum. To reconstruct flowering dates, information from literature and herbarium collections was consulted and more than 990 records were gathered. Flowering cycles were estimated by recording the intervals between reported flowering events. Evidence of regular flowering cycles of ca. 30 years was found for most of the species considered. There is a remarkable concentration of flowering cycles about multiples of 15–16 years. Flowering synchrony among different species of woody bamboos was recorded for the first time in South America.     

Clonal structure and flowering traits of a bamboo [Phyllostachys pubescens (Mazel) Ohwi] stand grown from a simultaneous flowering as revealed by AFLP analysis

Abstract Although many bamboo species are characterized by simultaneous flowering at long intervals of up to 120 years, few studies have revealed the length of the flowering interval for very-long-lived bamboo species by observing the whole life cycle of a single clone. The flowering interval of Phyllostachys pubescens had been determined to be 67 years by means of observation through the entire life cycle from 1912 to 1979. We observed and analysed the clonal structure and flowering traits of a P. pubescens community which had regenerated from seed in 1930 and began to flower in 1997. Although this interval was again 67 years, flowering and nonflowering culms were mixed, and the flowering event lasted three years in the community. AFLP analysis of DNA samples showed distinct genets that originated from the previous flowering event and that each genet had its own flowering time. This is the first report to show that (i) different genets are mixed in a community of a large bamboo species with a leptomorphic rhizome system, and (ii) a community that originated from a single flowering event can have a range of flowering years.