来自中国云南野生稻的抗稻瘟病遗传资源

与Pi-ta^＋等位基因相比,含有Pi-ta^＋等位基因的栽培稻具有抗稻瘟病特性。本研究用基因序列分析的方法检测了来自云南的不同栽培稻品种以及不同类型和来源的普通野生稻种和非洲长雄蕊野生稻种中的Pi-ta^＋基因,发现Pi-ta地基因在稻属植物中高度保守,但Pi-ta^＋等位基因的存在极其稀有。在所检测的栽培稻和野生稻中仅有来源于云南景洪的直立型普通野生稻中含有Pi-ta^＋等位基因。而与Pi-ta基因相比,另一个水稻抗稻瘟病基因Pib,经部分同源序列克隆及测序发现该基因在不同野生稻中的变异较大。在所克隆的不同野生稻Pib基因同源序列中,也只有来源于直立型普通野生稻的序列能按该基因的开放阅读框进行正常翻译。对不同类型普通野生稻的抗稻瘟病能力的初步鉴定结果表明,直立型普通野生稻对供试的本地稻瘟病生理小种具有较强抗性,其抗性可能源于所含的Pi=ta^＋等位基因及可能有功能的Pib基因。由于普通野生稻与栽培稻同属AA基因组型,因此,云南直立型普通野生稻可通过杂交育种或基因工程途径用于栽培稻的抗稻瘟病性能改良。     

Evaluation of Genetic Diversity and Development of a Core Collection of Wild Rice (Oryza rufipogon Griff.) Populations in China

Common wild rice (Oryza rufipogon Griff.), the progenitor of Asian cultivated rice (O. sativa L.), is endangered due to habitat loss. The objectives of this research were to evaluate the genetic diversity of wild rice species in isolated populations and to develop a core collection of representative genotypes for ex situ conservation. We collected 885 wild rice accessions from eight geographically distinct regions and transplanted these accessions in a protected conservation garden over a period of almost two decades. We evaluated these accessions for 13 morphological or phenological traits and genotyped them for 36 DNA markers evenly distributed on the 12 chromosomes. The coefficient of variation of quantitative traits was 0.56 and ranged from 0.37 to 1.06. SSR markers detected 206 different alleles with an average of 6 alleles per locus. The mean polymorphism information content (PIC) was 0.64 in all populations, indicating that the marker loci have a high level of polymorphism and genetic diversity in all populations. Phylogenetic analyses based on morphological and molecular data revealed remarkable differences in the genetic diversity of common wild rice populations. The results showed that the Zengcheng, Gaozhou, and Suixi populations possess higher levels of genetic diversity, whereas the Huilai and Boluo populations have lower levels of genetic diversity than do the other populations. Based on their genetic distance, 130 accessions were selected as a core collection that retained over 90% of the alleles at the 36 marker loci. This genetically diverse core collection will be a useful resource for genomic studies of rice and for initiatives aimed at developing rice with improved agronomic traits.     

Biodiversity of Bitahai Nature Reserve in Yunnan Province, China

Bitahai Nature Reserve is located in Northwest Yunnan and is the highest elevation and the highest latitude wetland nature reserve in Yunnan Province. Bitahai Nature Reserve is a typical wetland nature reserve in very low latitude and high elevation with large areas of coniferous forest around the alpine till lakes, wetland and water area ecosystem while compared with natural reserves distributed same latitude in the world. The area of the reserve distribution is the key area of Transverse Mountain Region. It was a refuge for plant and wildlife because Transverse Mountains were not covered by ice in the Tertiary. And the area is now regarded as a center of forming new species and preserving ancient species. Species biodiversity is high and the distribution of some endemic animals and plants are limited in Transverse Mountains area. In the nature reserve, there are many first and second grade protected plants and animals listed in Lists of China National Priority Protection Fauna and Flora. All of these are precious materials of genetic diversity. The diversities of the plant community and vegetation contribute to ecosystem diversity. Thus, Bitahai Nature Reserve holds with high conservation value. However, its biodiversity is threatened by different factors and its conservation should be paid great attention.     

Molecular and Cytological Characterization of Centromeric Retrotransposons in a Wild Relative of Rice, Oryza granulata

Centromeric retrotransposons (CRs) are important component of the functional centromeres of rice chromosomes. To track the evolution of the CR elements in genus Oryza, we sequenced the orthologous region of the rice centromere 8 (Cen8) in O. granulata and analyzed transposons in this region. A total of 12 bacterial artificial chromosomes (BACs) that span the centromeric region in O. granulata were sequenced. The O. granulate centromeric sequences are composed of as much as 85% of transposons, higher than any other reported eukaryotic centromeres. Ten novel LTR retrotransposon families were identified but a single retrotransposon, Gran3, constitutes nearly 43% of the centromeric sequences. Integration times of complete LTR retrotransposons indicate that the centromeric region had a massive insertion of LTR retrotransposons within 4.5 million year (Myr), which indicates a recent expansion of the centromere in O. granulata after the radiation of the Oryza genus. Two retrotransposon families, OGRetro7 and OGRetro9, show sequence similarity with the canonical CRs from rice and maize. Both OGRetro7 and OGRetro9 are highly concentrated in the centromeres of O. granulata chromosomes. Furthermore, strong hybridization signals were detected in all Oryza species but in O. brachyantha with the OGRetro7 and OGRetro9 probes. Characterization of the centromeric retrotransposons in O. granulata confirms the conservation of the CRs in the Oryza genus and provides a resource for comparative analysis of centromeres and centromere evolution among the Oryza genus and other genomes.     

白马雪山自然保护区响古箐滇金丝猴的交配行为

灵长类交配模式是灵长类社群结构和婚配制度的重要表征之一,其研究有助于了解灵长类社群结构和两性交配策略。2013年11月至2014年10月,我们对云南白马雪山国家级自然保护区一人工辅助投食滇金丝猴群进行了观察研究,采用焦点动物取样法和全事件记录法收集了雌雄个体交配相关的行为数据,主要包括邀配对象、交配过程、持续时间和回合数,以及参与交配的雌雄对在交配结束后的相互理毛的持续时间和回合数。研究结果表明:研究群滇金丝猴全年均有交配行为,交配高峰期在7-9月,两性参与交配的积极性和对季节变化的响应不同;交配主要由雌性通过邀配发动(76%),交配高峰期也是雌性邀配的高峰期;雄性爬跨频次(年均0.43次/月,n=5)和射精爬跨比(年均19%,n=5)在全年无显著变化。交配行为发生的典型表现为:雌性通过小跑或跳跃进入雄性视线范围内,爬伏呈臀向雄性邀配;雌猴爬伏时离雄猴的远近距离不同(1 m vs.2-5 m:69%vs.31%)会影响其邀配成功率(1 m vs.2-5 m:68%vs.40%);若一次邀配失败,雌猴可能会连续爬伏邀配(最多4次),连续多次邀配的成功率显著高于单次邀配(79%vs.52%)。交配结束后雌性会主动为雄性理毛,但雌性主动理毛与交配是否射精无关。     

云南元江普通野生稻中Pi-ta和Pib同源基因的克隆和分析

用高保真PCR技术从云南元江普通野生稻中克隆了抗稻瘟病Pi-ta同源基因的编码区及Pib基因的部分同源序列。Pi-ta同源基因的编码区序列与报道的栽培稻有99.7%的同源性。根据前人的结果,从元江普通野生稻的Pi-ta基因推导的氨基酸序列中918位点为丝氨酸,属于Pi-ta~-等位基因,不能对含有AVRPita基因的稻瘟病菌产生抗性。与Pi-ta基因相比,元江普通野生稻中的Pib同源基因第一外显子与栽培稻的相应序列间存在较大差异,其中有一段87 bp的DNA序列缺失,而且不能按正常的Pib基因序列的阅读框进行翻译。因此认为,元江普通野生稻不具有基于Pi-ta和Pib基因的抗稻瘟病遗传基础。     

广东象头山国家级自然保护区蛇类多样性及保护研究

目的了解广东象头山国家级自然保护区蛇类多样性现状,探讨保护区蛇类资源的有效保护对策。方法采用访问调查和野外样带调查相结合的方法。结果该保护区现已纪录蛇类有5科45种,占中国已纪录蛇类物种数的22．0％,占广东省已纪录蛇类物种数的46．4％,区系组成以东洋界华中区和华南区共有种为主,占82．2％。保护区有国家Ⅰ级重点保护野生动物蚺双带亚种（蟒蛇）（Python molurus bivittatus）,以及舟山眼镜蛇（Najaatra）、眼镜王蛇（Ophiophagus hannah）、灰鼠蛇（Ptyas korros）和滑鼠蛇（Ptyas mucosus）等15种重要经济蛇类。结论广东象头山国家级自然保护区蛇类物种多样性十分丰富,但长期过度猎捕和栖息地遭破坏导致保护区一些蛇类种群数量明显减少,需加强保护。本文针对保护区蛇类保护问题提出5点建议。     

云南哀牢山国家级自然保护区药用蕨类植物资源

报道哀牢山国家级自然保护区药用蕨类植物资源。通过两年多的野外考察（标本存于PYU）和查阅原标本文献记载（PYU和KUN）,首次报道了哀牢山蕨类区系有蕨类植物48科,118属,446种（包括变种和变型）。哀牢山蕨类区系是亚热带性质的区系。哀牢山国家级自然保护区可供经济利用的蕨类超过300余种,其中,药用蕨类植物有45科76属178种,占中国药用蕨类植物科属种的比例分别为91．8％、65．5％和41．1％。最后讨论了哀牢山药用蕨类植物资源的保护与开发利用。     

广东鼎湖山国家级自然保护区爬行动物多样性与保护

2006～2011年采用野外调查和访问调查相结合的方法,对广东鼎湖山国家级自然保护区爬行动物进行了专项调查研究。迄今,该保护区已记录爬行动物2目12科54种,其中6种为本次调查发现的新纪录,分别是截趾虎Gehyra mutilata、丽棘蜥Acanthosaura lepidogaster、棕黑腹链蛇Amphiesma sauteri、黑领剑蛇Sibynophis collaris、细白环蛇Lycodon subcinctus和乌龟Mauremys reevesii。本次调查野外发现爬行动物共38种,其中包括珍稀濒危物种平胸龟Platysternon megacephalum,16种文献有记载的爬行动物在本次调查中未发现。访问调查发现6只四眼斑水龟Sacalia quadriocellata,很可能来自鼎湖山。基于调查结果,对该保护区爬行动物多样性及受胁因素进行了探讨,并提出了4点保护管理建议。     

A New Species of Cyrtodactylus(Squamata: Gekkonidae) from the Karst Forests of Daweishan National Nature Reserve,Yunnan, China

Cyrtodactylus geckos are one of the most speciose and diverse groups of extant lizards known, distributed throughout the Asian and Pacific realms. Using molecular phylogenetic methods and supporting morphological data,we describe a new species of Cyrtodactylus in Daweishan National Nature Reserve, Yunnan Province, China.Cyrtodactylus hekouensis sp. nov. can be morphologically distinguished from its nearby congeners by the following characters: maximum SVL 92.3 mm and TL 98.5 mm;11–12 supralabials; 11–12 infralabials; 36–57 scale rows between the fifth supralabials; 10–13 dorsal tubercles rows;3 postnasals on blunt and smooth front snout; precloacalfemoral pores in a continuous series of 33–39(females with pitted scales) located under vent/cloaca and thighs in both sexes; precloacal groove absent; 3/3 postcloacal tubercles;subdigital lamellae under the fourth finger 21 or 22, under the fourth toe 20–23; smooth midbody with smooth venter and tuberculate dorsal scale rows, tubercles from head to tail base; dorsal transverse patterns are generally large,bilaterally symmetrical. The results of the phylogenetic analysis recover specimens of this new species as sister to a clade containing C. wayakonei and C. martini. Uncorrected pairwise intraspecific distances were 1%, and distances between our new species and other Cyrtodactylus species from nearby countries ranged from 14.2% to 26.8%.     

Diversity and Antimicrobial Activity of Endophytic Actinomycetes Isolated from Plant Roots in Thailand

Microbiology - In this study, 37 endophytic actinomycetes were isolated from roots of 14 plant species obtained in Thailand, where biological diversity is known to be high. The isolates were...     

广西普通野生稻(Oryza rufipogon Griff)表型性状和SSR多样性研究

以中国普通野生稻初级核心种质中广西普通野生稻部分中的 2 2 3份野生稻为材料 ,以平均分布于水稻 12条染色体上的 34对SSR引物和中国稻种资源目录中的表型性状分析广西普通野生稻SSR位点的等位变异、多样性的地理分布及不同生长习性间的多样性分布等。结果表明 ,每对引物检测到的多态性片段 7～ 4 8条 ,平均为 2 4 .91条 ,普通野生稻的等位变异数明显大于地方稻种 ,在所分析的SSR位点中杂合位点比例变化在 1.35 %～ 81.31%之间 ,平均为 32 .0 1% ,与自花授粉的栽培稻相比具有较高的杂合率 ;北纬 2 2°～ 2 3°和 2 3°～ 2 4°范围内的两个区域内(一个包括隆安、扶绥和邕宁三县 ,另一个包括象州、来宾、武宣、玉林和贵港五个县 )所包含的普通野生稻数量多 ,遗传多样性大 ,在DNA水平上是广西普通野生稻的遗传多样性中心 ,而表型性状多样性中心是在北纬 2 1°～ 2 2°和2 2°～ 2 3°,其多样性分布与DNA水平不完全一致。在 4种生长习性间 ,DNA水平上的遗传多样性大小依次为匍匐型 ,倾斜型 ,半直立型和直立型 ,表型水平的多样性与DNA水平的多样性基本一致。     

广西大王岭自然保护区两栖动物多样性调查与分析

2007年8月对广西大王岭自然保护区的两栖动物进行了调查,结果表明,该保护区有18种两栖动物,隶属12属6科2目.其Shannon-Wiener多样性系数为2.4842,均匀度系数为0.8768.对两栖动物的区系及多样性进行了分析,并提出保护对策.     

云南纳帕海自然保护区灰背伯劳的巢址选择

2013年5—6月,在云南省纳帕海自然保护区对灰背伯劳Lanius tephronotus的巢址选择进行了研究。结果显示,灰背伯劳对树种具有极强的偏好性,有78.48%(n=62)的巢位于火棘Pyracantha sp.灌丛中,枝条具刺是影响灰背伯劳选择筑巢树的首要因素。主成分分析表明,影响灰背伯劳巢址选择的因素有5类:距离因子(巢距道路距离、距居民点距离)、安全性因子(刺数量、刺长度)、觅食生境因子(耕地占比)、隐蔽度因子(树冠幅、树高)以及巢生境因子(灌木占比)。总之,灰背伯劳喜好营巢于距离居民点较近、巢周围耕地面积较大的多刺灌丛。房屋和道路修建对灌丛的侵占是威胁灰背伯劳生存的主要因素。     

花坪自然保护区国家重点保护野生植物调查

广西花坪自然保护区分布有国家重点保护野生植物17种,隶属于16科17属。国家重点保护野生植物区系成分复杂、具亚热带性质,特有属和单型属较多,起源古老。国家重点保护野生植物资源丰富,并提出了保护措施。     

海南普通野生稻OrERF1的克隆和表达分析

根据EST(expressed sequence tags,EST)序列信息,从海南普通野生稻中克隆了一个AP2/ERF(apetala2/ethylene response factor)类转录因子OrERF1。该基因包含一个1 014 bp的完整阅读框,编码337个氨基酸。推导OrERF1氨基酸序列具有典型的AP2/ERF类转录因子结构特征,与水稻(Oryza sativa)、大麦(Hordeum vulgare)、玉米(Zea mays)和橙子(Citrus sinensis)中相应的AP2/ERF类蛋白具有较高的同源性。聚类分析表明OrERF1是ERF类转录因子。对OrERF1启动子序列进行分析,发现存在多种激素应答和胁迫响应的调控元件。Real-time PCR结果显示,低温、干旱和盐胁迫均能诱导OrERF1的表达。这些结果表明OrERF1可能在逆境响应过程中具有重要功能。     

Coordination of Leaf Photosynthesis,Transpiration, and Structural Traits in Rice and Wild Relatives (Genus Oryza)

The genus Oryza, which includes rice (Oryza sativa and Oryza glaberrima) and wild relatives, is a useful genus to study leaf properties in order to identify structural features that control CO₂ access to chloroplasts, photosynthesis, water use efficiency, and drought tolerance. Traits, 26 structural and 17 functional, associated with photosynthesis and transpiration were quantified on 24 accessions (representatives of 17 species and eight genomes). Hypotheses of associations within, and between, structure, photosynthesis, and transpiration were tested. Two main clusters of positively interrelated leaf traits were identified: in the first cluster were structural features, leaf thickness (Thick_leaf), mesophyll (M) cell surface area exposed to intercellular air space per unit of leaf surface area (S_mes), and M cell size; a second group included functional traits, net photosynthetic rate, transpiration rate, M conductance to CO₂ diffusion (g_m), stomatal conductance to gas diffusion (g_s), and the g_m/g_s ratio. While net photosynthetic rate was positively correlated with g_m, neither was significantly linked with any individual structural traits. The results suggest that changes in g_m depend on covariations of multiple leaf (S_mes) and M cell (including cell wall thickness) structural traits. There was an inverse relationship between Thick_leaf and transpiration rate and a significant positive association between Thick_leaf and leaf transpiration efficiency. Interestingly, high g_m together with high g_m/g_s and a low S_mes/g_m ratio (M resistance to CO₂ diffusion per unit of cell surface area exposed to intercellular air space) appear to be ideal for supporting leaf photosynthesis while preserving water; in addition, thick M cell walls may be beneficial for plant drought tolerance.Leaves have evolved in different environments into a multitude of sizes and shapes, showing great variation in morphology and anatomy (Evans et al., 2004). However, all leaf typologies share common functions associated with chloroplasts, namely to intercept sunlight, take up CO₂ and inorganic nitrogen, and perform photosynthesis as a primary process for growth and reproduction.Investigating relationships between leaf anatomy and photosynthetic features (CO₂ fixation, which involves physical and biochemical processes and loss of water by transpiration) could lead to the identification of structural features for enhancing crop productivity and improve our understanding of plant evolution and adaptation (Evans et al., 2004).Stomata, through which CO₂ and water vapor diffuse into and out of the leaf, are involved in the regulation and control of photosynthetic and transpiration responses (Jarvis and Morison, 1981; Farquhar and Sharkey, 1982). Besides stomata distribution patterns between the abaxial and adaxial lamina surfaces (Foster and Smith, 1986), stomatal density and size are leaf anatomical traits contributing to build the leaf stomatal conductance to gas diffusion (g_s). This is calculated as the reciprocal of the stomatal resistances to gas diffusion; stomatal control results in a lower concentration of CO₂ in the leaf mesophyll (M) intercellular air space (C_i) than in the atmosphere (C_a; Nobel, 2009).Leaf M architecture greatly contributes to the pattern of light attenuation profiles within the lamina (Terashima and Saeki, 1983; Woolley, 1983; Vogelmann et al., 1989; Evans, 1999; Terashima et al., 2011) and affects CO₂ diffusion from the intercellular air space (IAS) to the chloroplast stroma. Therefore, it influences photosynthetic activity (Flexas et al., 2007, 2008) and can have effects on leaf hydrology and transpiration (Sack et al., 2003; Brodribb et al., 2010; Ocheltree et al., 2012). In addition, M architecture sets boundaries for leaf photosynthetic responses to changing environmental conditions (Nobel et al., 1975).Fortunately, several methodologies are currently available (Flexas et al., 2008; Pons et al., 2009) to determine M conductance to CO₂ diffusion (g_m), expressed per unit of leaf surface area. It is calculated as the reciprocal of the cumulated partial resistances exerted by leaf structural traits and biochemical processes from the substomatal cavities to photosynthetic sites (Evans et al., 2009; Nobel, 2009). The resistance to CO₂ diffusion in the liquid phase is 4 orders of magnitude higher than in the gaseous phase (Nobel, 2009); therefore, the changes in CO₂ concentration in the leaf gas phase are small in comparison with the changes in the liquid phase (Niinemets, 1999; Aalto and Juurola, 2002; Nobel, 2009). In the liquid phase, the resistance to CO₂ transfer is built from contributions by the cell walls, the plasmalemma, cytoplasm, chloroplast membranes, and stroma (Tholen and Zhu, 2011; Tholen et al., 2012); in addition, it involves factors associated with the carboxylation reaction (Kiirats et al., 2002; Evans et al., 2009). Thus, the concentration of CO₂ in the chloroplasts (C_c) is lower than C_i and can limit photosynthesis.At steady state, the relationships between the leaf net photosynthetic rate (A), the concentrations of CO₂, and the stomatal conductance to CO₂ diffusion (g_{s_CO2}) and g_m are modeled based on Fick’s first law of diffusion (Nobel, 2009) as:(1)where C_a, C_i, and C_c are as defined above (Flexas et al., 2008).The magnitude of g_m has been found to correlate with certain leaf structural traits in some species, in particular with the M cell surface area exposed to IAS per (one side) unit of leaf surface area (S_mes) and its extent covered by chloroplasts (S_chl; Evans and Loreto, 2000; Slaton and Smith, 2002; Tholen et al., 2012). From a physical modeling perspective, increasing S_mes provides more pathways acting in parallel for CO₂ diffusion (to and from the chloroplasts) per unit of leaf surface area; thus, it tends to reduce the resistance to CO₂ movement into the M cells and to increase g_m (Evans et al., 2009; Nobel, 2009). A number of leaf structural traits affect S_mes, including leaf thickness, cell density, cell volume and shape, and the fraction of the M cell walls in contact with the IAS (Terashima et al., 2001, 2011), and the degree they are linked to S_mes can vary between species (Slaton and Smith, 2002; Terashima et al., 2006). In particular, the presence of lobes on M cells, which are prominent in some Oryza species, may contribute to g_m through increasing S_mes (Sage and Sage, 2009; Terashima et al., 2011; Tosens et al., 2012). The M cell wall can provide resistance in series for M CO₂ diffusion (Nobel, 2009); thicker cell walls may increase resistance to CO₂ movement into the M cells and decrease g_m (Terashima et al., 2006, 2011; Evans et al., 2009).Other leaf traits, such as M porosity (the fraction of M volume occupied by air spaces [Vol_IAS]), has been shown to have a positive correlation with g_m in some species (Peña-Rojas et al., 2005), but the association may be mediated by light availability (Slaton and Smith, 2002). Leaf thickness (Thick_leaf) tends to be negatively linked to g_m, and it may set an upper limit for the maximum g_m, according to Terashima et al. (2006), Flexas et al. (2008), and Niinemets et al. (2009).With respect to leaf structural traits and water relations, Thick_leaf may increase the apoplast path length (resistances in series; Nobel, 2009) in the extra-xylem M (Sack and Holbrook, 2006; Brodribb et al., 2007) for water to reach the evaporation sites, which could decrease the conductance of water through the M and lower the transpiration rate. Interestingly, while thicker M cell walls may reduce g_m, they can enable the development of higher water potential gradients between the soil and leaves, which can be decisive for plant survival and longevity under drought conditions (Steppe et al., 2011).The purpose of this study was to provide insight into how the diversity of leaf structure relates to photosynthesis and transpiration among representative cultivated species and wild relatives in the genus Oryza. This includes, in particular, identifying leaf structural features associated with the diffusion of CO₂ from the atmosphere to the chloroplasts, photosynthesis, transpiration efficiency (A/E), and drought tolerance. The genus consists of 10 genomic groups and is composed of approximately 24 species (the number depending on taxonomic preferences; Kellogg, 2009; Brar and Singh, 2011), including the cultivated species Oryza sativa and Oryza glaberrima. Oryza species are distributed around the world, and they exhibit a wide range of phenotypes, with annual versus perennial life cycles and sun- versus shade-adapted species (Vaughan, 1994; Vaughan et al., 2008; Brar and Singh, 2011; Jagadish et al., 2011). This diversity in the genus is an important resource, which is being studied to improve rice yield, especially under unfavorable environmental conditions. In particular, O. glaberrima, Oryza australiensis, and Oryza meridionalis are of interest as drought-tolerant species (Henry et al., 2010; Ndjiondjop et al., 2010; Scafaro et al., 2011, 2012), while Oryza coarctata is salt tolerant (Sengupta and Majumder, 2010). In this study, a total of 43 leaf functional and structural parameters were collected on 24 accessions corresponding to 17 species within eight genomes (Brar and Singh (2011). Life cycle is as follows: A = annual; B = biennial; P = poliennial. Habitat is as follows: S = shade; S-Sh = sun-shade.

Genetic Evaluation of in situ Conserved and Reintroduced Populations of Wild Rice (Oryza rufipogon: Poaceae) in China

We evaluated the genetic consequences and efficiency of conservation practices in Oryza rufipogon using microsatellite DNA markers. Spatial autocorrelation analysis from 12 microsatellite loci revealed that microsatellite alleles were exclusively distributed in patches within the population, indicating that large populations were unlikely to be homogeneous. An in situ conserved stand of O. rufipogon, which has been protected by a concrete wall from a large population, captured only 67.9% of the total genetic variation of the previous large population. The concrete wall was built to protect the wild rice, but it acted more as a physical barrier to gene exchanges between the two sides. An assignment test revealed only 11.1% putative seed exchanges across the wall. A reintroduced population was found to be genetically very diverse. About 76.3% of the total genetic variation detected in other populations was captured in this reintroduced population, and 24.8% of the total genetic variation in this population was not found in other populations. These results display two important findings for conservation of O. rufipogon. First, conserving one part of a large population of O. rufipogon will not preserve an adequate sample of the genetic variability, since populations are not homogeneous, and genotype distribution varies among localities. Second, a reintroduced population is not genetically depauperate, but it is too early to assess its long-term survival.