Musa chunii Hakkinen, a new species (Musaceae) from Yunnan,China and taxonomic identity of Musa rubra

The center of diversity of the genus Musa (Musaceae) is in Southeast Asia, a region not studied in detail and where new species and varieties continue to be reported. A new wild banana species, M. chunii Hakki-nen from Yunnan, China is described and illustrated based on observed morphological characteristics in the field. This extremely rare new species was only found in Tongbiguan Nature Reserve, Dehong District, West Yunnan. A key to M. chunii and related taxa is provided. In addition, critical notes regarding M. rubra Kurz identity are given.     

Musa chunii Häkkinen,a new species (Musaceae) from Yunnan,China and taxonomic identity of Musa rubra

The center of diversity of the genus Musa (Musaceae) is in Southeast Asia, a region not studied in detail and where new species and varieties continue to be reported. A new wild banana species, M. chunii Häkkinen from Yunnan, China is described and illustrated based on observed morphological characteristics in the field. This extremely rare new species was only found in Tongbiguan Nature Reserve, Dehong District, West Yunnan. A key to M. chunii and related taxa is provided. In addition, critical notes regarding M. rubra Kurz identity are given.     

A new species of the wild banana genus,Musa (Musaceae), from Borneo

A new species of wild banana, Musa bauensis Häkkinen & Meekiong, is described and illustrated. It is from the Bau limestone area, Sarawak, East Malaysia.     

Effects of light regime on δ13C,photosynthesis and yield of field-grown banana (Musa sp., Musaceae)*

Banana plants (Musa sp., Musaceae) were grown for 2 years in the field in 12×20m plots under irradiance levels incident upon the canopy of 100, 81, 62 and 32% of sunlight. Time-integrated parameters such as leaf δ¹³C, yield and leaf mass to area ratio were linearly correlated with irradiance level (R²>0.9). In contrast, midday CO₂ assimilation and transpiration efficiency (A/g) decreased significantly and substomatal CO₂ concentrations (c_st) increased significantly only at the lowest irradiance levels (below 81% irradiance). Diurnal gas exchange measurements indicated that the linear response of the long-term parameters may be associated with the significant variations in photosynthetic activity among the irradiance treatments observed only in the early morning hours. The linear fit between yield and irradiance level (per cent of control) had a slope of 0.82 (with apparently constant yield to biomass ratio). These results directly demonstrate the significance of variations in incident light, such as may be associated with increasing cloudiness, on productivity of tropical plants such as the banana. The importance of using time-integrated indicators in general, and the reliability of using ¹³C discrimination in particular, in evaluating the responses of plants to changes in incident irradiance is demonstrated.     

Genetic diversity and population genetic structure of wild banana Musa ornata (Musaceae) in Mexico

The wild banana Musa ornata is an inhabitant of the tropical regions of Mexico characterized by patches of tropical rainforest. The overexploitation of its habitat has caused the extinction of several populations affecting diversity and population genetic structure of remaining ones. We used microsatellite markers to determine the genetic diversity and the population’s genetic structure of all extant populations. The thirty-two microsatellite loci previously characterized for M. acuminata and M. balbisiana were tested in M. ornata. Only twelve amplified. From these seven were polymorphic and were used for genetic analyses. The Nei’s diversity estimator shows low levels of genetic diversity (H _e = 0.263) with a mean of 4.40 alleles per locus. Excess homozygosity was evident in all populations indicating high levels of inbreeding. F _ST pairwise analyses and AMOVA indicated low genetic differentiation. However, 28 % of private alleles were registered, suggesting limited gene flow. Genetic distances, Jaccard’s coefficient and principal component analysis showed a good correspondence to geographical locations. The Mantel test performed was not significant. The results support the hypothesis of recent fragmentation events; therefore, not enough time has passed to detect differences between populations. However, it is also likely that results are caused by factors such as bottleneck, decline in pollinator populations, self-pollination and/or a tendency towards clonal reproduction. It is proposed that the preservation strategy focuses on maintaining all the remaining populations and ensuring their connectivity, so as to maintain gene flow and increase the genetic diversity of this species.     

Taxonomic Notes on Nasutitermes and Bulbitermes (Termitidae, Nasutitermitinae) from the Sunda region of Southeast Asia based on morphological and molecular characters

The Sunda region of Southeastern Asia is rich in termite fauna, but termites from this region have been poorly described. In this study, we described eight species from two diverse genera from this region, and from the family Termitidae. We describe Bulbitermes 4 spp. and Nasutitermes 4 spp. from new field collections. Where possible we examine original holotype specimens, and describe the essential morphological characters for soldier and worker castes. We devise two new bifurcating keys to guide the field identification of each species. In addition, we develop a nucleotide sequence profile for the COI gene. From this molecular character matrix, we use Neighbour-Joining analysis to test the monophyly of each morphospecies and genus. We find that the morphological and molecular characters are highly concordant, whereby all taxa appear to represent distinct molecular clades. For termites, there is therefore agreement between the morphological taxonomic characters used to sort species from a bifurcating key and the molecular taxonomic characters used to sort species on a bifurcating tree. This joint analysis suggests that DNA barcoding holds considerable promise for termite taxonomy, especially for diverse clades like Bulbitermes and Nasutitermes for which a global morphological key would be intractable.     

Population structure of wild bananas, Musa balbisiana, in China determined by SSR fingerprinting and cpDNA PCR-RFLP

Both demographic history and dispersal mechanisms influence the apportionment of genetic diversity among plant populations across geographical regions. In this study, phylogeography and population structure of wild banana, Musa balbisiana, one of the progenitors of cultivated bananas and plantains in China were investigated by an analysis of genetic diversity of simple sequence repeat (SSR) fingerprint markers and cpDNA PCR-RFLP. A chloroplast DNA (cpDNA) genealogy of 21 haplotypes identified two major clades, which correspond to two geographical regions separated by the Beijiang and Xijiang rivers, suggesting a history of vicariance. Significant genetic differentiation was detected among populations with cpDNA markers, a result consistent with limited seed dispersal in wild banana mediated by foraging of rodents. Nuclear SSR data also revealed significant geographical structuring in banana populations. In western China, however, there was no detected phylogeograpahical pattern, possibly due to frequent pollen flow via fruit bats. In contrast, populations east of the Beijiang River and the population of Hainan Island, where long-range soaring pollinators are absent, are genetically distinct. Colonization-extinction processes may have influenced the evolution of Musa populations, which have a metapopulation structure and are connected by migrating individuals. Effective gene flow via pollen, estimated from the nuclear SSR data, is 3.65 times greater than gene flow via seed, estimated from cpDNA data. Chloroplast and nuclear DNAs provide different insights into phylogeographical patterns of wild banana populations and, taken together, can inform conservation practices.     

Policies,Political-Economy,and Swidden in Southeast Asia

For centuries swidden was an important farming practice found across the girth of Southeast Asia. Today, however, these systems are changing and sometimes disappearing at a pace never before experienced. In order to explain the demise or transitioning of swidden we need to understand the rapid and massive changes that have and are occurring in the political and economic environment in which these farmers operate. Swidden farming has always been characterized by change, but since the onset of modern independent nation states, governments and markets in Southeast Asia have transformed the terms of swiddeners’ everyday lives to a degree that is significantly different from that ever experienced before. In this paper we identified six factors that have contributed to the demise or transformation of swidden systems, and support these arguments with examples from China (Xishuangbanna), Laos, Thailand, Malaysia, and Indonesia. These trends include classifying swiddeners as ethnic minorities within nation-states, dividing the landscape into forest and permanent agriculture, expansion of forest departments and the rise of conservation, resettlement, privatization and commoditization of land and land-based production, and expansion of market infrastructure and the promotion of industrial agriculture. In addition we note a growing trend toward a transition from rural to urban livelihoods and expanding urban-labor markets.

闽江流域野生蕉(Musa itinerans)遗传多样性和遗传结构的ISSR分析

采用ISSR分子标记技术对福建省闽江流域10个野生蕉自然居群的遗传多样性和遗传结构进行分析,结果显示:12条ISSR引物共检测出117个条带,105个多态性条带,多态性百分率为89.7%;野生蕉Nei遗传多样性指数为0.244,Shannon's信息指数为0.381,其中三明野生蕉遗传多样性水平最高,且不同自然居群间遗传多样性指数之间具有显著性差异;总遗传变异系数为0.589,基因流为0.349,居群间的遗传分化程度高于居群内;基于遗传距离的聚类结果与模型聚类结果均聚为3大类,分别为沙溪支流的三明野生蕉类群、闽江上游及附近支流的南平野生蕉类群和闽江下游的福州野生蕉类群。研究认为,闽江流域野生蕉资源丰富的遗传多样性主要来源于自然居群间生境异质化所引起的高频率遗传变异,且三明野生蕉类群的遗传多样性和遗传分化程度最高,可能是福建野生蕉的起源中心,也是野生蕉资源开发和利用的最主要群落。此外,水流是闽江流域野生蕉遗传迁移最关键的自然主导因素。     

A taxonomic reevaluation of freshwater ostracods (Crustacea,Ostracoda) referred to the genus Cypridopsis Brady, 1868 from Southeast Asia

A taxonomic reevaluation of five species of Southeast Asian freshwater ostracods formerly assigned to the genus Cypridopsis Brady, 1868 has resulted in the retention of Cypridopsis adusta Sars, 1903, Cypridopsis exigua Sars, 1903 and Cypridopsis dubia Sars, 1903 in Cypridopsis and transfer of Cypridopsis albida (Vavra) 1898 and Cypridopsis arsenia Tressler, 1937 to the genus Plesiocypridopsis Rome, 1965.     

大蕉苯丙氨酸解氨酶基因的克隆、鉴定和表达分析

为了研究苯丙氨酸解氨酶基因与大蕉(Musa ABB cv. Dongguandajiao)抗枯萎病的关系,利用 RT-PCR 和 RACE技术克隆了大蕉苯丙氨酸解氨酶基因全长 cDNA。此 cDNA 长 1 300 bp,包含一个长为 1 191 bp,编码 397 个氨基酸的完整开放阅读框(ORF),推导的氨基酸序列与水稻 PAL 基因氨基酸序列同源性达 89%,将此基因命名为 M-PAL。Southern杂交结果表明大蕉中存在一个包含 4-5 个 PAL基因的基因家族,将此基因克隆到大肠杆菌表达载体 pET32(a )中,表达的蛋白质分子量大小与推导的相一致,并且表达的蛋白质表现出 PAL 酶活性。对接种香蕉枯萎病菌 4 号生理小种(Fusarium oxysporumf. sp. cubense (FOC) race 4 )后大蕉叶片中 M-PAL基因的转录谱进行研究表明,在接种枯萎病菌后,M-PAL基因在叶片中的转录水平提高,因此推测 M-PAL基因的表达可能与香蕉枯萎病抗性相关。     

Freshwater ostracods (Crustacea: Ostracoda) of the subfamily Dolerocypridinae Triebel, 1961 from Southeast Asia

The systematics of the freshwater ostracods of the subfamily Dolerocypridinae in Southeast Asia is reviewed: A total of five species are known and they are assigned to three genera. Astenocypris papyracea (Sars) 1903 and Dolerocypris sinensis Sars, 1903 are redescribed. Dolerocypris fasciata (Müller) 1776, from Indonesia is figured and the hitherto observed variations are discussed. Dolerocypris pellucida Klie, 1932 is transferred to the genus Tanycypris Triebel, 1959.     

东南亚兰科植物的物种多样性、生活习性及其传粉系统（附表）

兰科(Orchidaceae)植物广布于除两极和极端沙漠地区外的各种陆地生态系统,包括5个亚科800多属28 000多种。东南亚地区兰科植物种数约占世界的1/3,是兰科植物生物多样性热点区域之一。通过查阅文献及书籍等资料,该文系统整理了东南亚兰科植物物种种类及其扩散演化历史,并对其生活习性和传粉系统进行了归类。结果表明:(1)东南亚兰科植物8 855种,分属5亚科17族26亚族240属;(2)主要生活型为附生的有127属6 000种以上,地生97属2 000种以上,腐生13属约100种,藤本4属40余种;(3)根据整理出的东南亚79个属的兰科植物传粉系统发现,有44个属含有自动自交的物种,具报酬物的传粉系统有花粉(仅见于拟兰亚科)、芳香类物质(仅见于香荚兰亚科)和花蜜(5个亚科均有)等报酬物类型。欺骗性传粉系统广泛存在于各个亚科,包括食源性欺骗、性拟态、繁殖地拟态和信息素拟态等类型。东南亚兰科植物在物种、生活习性及传粉系统都展现出极高的多样性,对这些生物学特点的总结将为兰科植物的保育提供一定的理论基础和本底资料。