栽培植物野生近缘种的保护与利用

栽培植物是人类赖以生存和发展的重要物质基础。全球人口与人均需求量的持续增长导致对植物资源的需求与日俱增。栽培植物较低的遗传多样性是限制其产量增长和质量提高的主要因素。栽培植物野生近缘种在自然环境中积累了丰富的遗传变异, 并在应对环境变化的过程中产生了很多新的适应性状, 是栽培植物种质创新和品种改良的重要遗传资源。然而, 栽培植物野生近缘种的存续和自然进化因生境破坏以及全球气候变化等正面临严重威胁, 需要采取有效的措施进行保护。本文总结了国内外对栽培植物野生近缘种进行原生境保护与迁地保护所取得的进展, 并基于我国实际情况提出了栽培植物野生近缘种的保护建议。此外, 本文还对栽培植物野生近缘种利用技术进行了梳理, 探讨了栽培植物野生近缘种遗传资源可持续利用的新思路。最后, 我们以长江流域几种代表性栽培植物为例, 对主要作物类型的保护与利用情况进行了讨论。     

作物野生近缘植物保护与可持续利用

作物与人类文明的传承和发扬密不可分。世界人口和人均需求量的持续增加导致植物资源的供需失衡。作物自身相对较低的遗传多样性是影响产量和品质的主要因素。作物野生近缘植物在生境中积累了多种基因型,并在应对环境变化时形成了多种表现型,是作物种质保护和品种改良的重要遗传资源。但随着生境破坏以及全球气候变化等不确定因素的持续影响,使得作物野生近缘植物的存活和繁殖质量受到了严重威胁,必须采取有效的措施进行保护。本文总结了国内外对作物野生近缘植物保护工作所取得的进展,应对我国在保护中存在的问题提出相应的改良建议。最后以国内代表性作物为例,对其保护与利用情况进行了讨论。     

作物野生近缘种的研究与保护需要重视

<正>作物野生近缘种(crop wild relatives,CWR)是宝贵的植物遗传资源,对于改良作物品种,提高粮食和其他栽培植物的产量和质量具有十分重要的意义。这是因为野生种的遗传多样性十分丰富,而现代栽培品种的遗传多样性却非常贫乏。在生物技术快速发展的今天,野生植物,特别是作物野生近缘种的利用前景更加广阔。     

中国作物野生近缘植物资源

中国地域辽阔,气候多样,地形复杂,土壤类型繁多,加之农业历史悠久,不仅作物种类众多,而且很多作物都有其野生近缘种,从而使得中国成为世界作物的重要起源中心之一。本文在介绍中国作物种类的同时,列出了各类作物的野生近缘植物资源,为进一步深入研究和开发利用这些资源,以及国家制定野生植物保护有关政策提供基础数据和信息。     

湖北的主要板栗品种资源及其野生近缘种

在实地调查及引种观察的基础上 ,对湖北 1 2个主要地方板栗品种的经济性状进行比较 ,并对其中的 6个主栽优良大果形品种作较详细的描述。此外 ,对湖北境内的野生板栗 ( Castanea mollissima Bl.) ,茅栗 ( C. se-quinii Dode) ,锥栗 ( C.henryi Rehd.& Wils)的特性及利用价值进行评价 ,首次报道了一种适合于嫁接栽培板栗的茅栗居群。     

狗尾草属野生近缘种的染色体鉴定

对来自多个国家和地区的10个种(青狗尾草S.viridis,法氏狗尾草S.faberii,轮生狗尾草S.verticillata、S.verticillifor-mis,金色狗尾草S.glauca、S.pumila、S.grisebachii、S.leucopila、S.parviflora、S.queenslandica等)50份狗尾草材料进行了染色体计数及倍性鉴定。发现狗尾草属中的青狗尾草均为二倍体,金色狗尾草S.glauca有四倍体和八倍体,轮生狗尾草S.verticillata有二倍体和四倍体,法氏狗尾草S.faberii为四倍体,S.pumila有二倍体和四倍体,S.grisebachii为二倍体,S.leucopila为二倍体,S.queenslandica为四倍体。本研究中对S.grisebachii、S.leucopila、S.queenslandica3个种是首次染色体倍性观察。发掘近缘种的有益基因是作物育种的重要途径之一,本研究搜集的谷子近缘野生种对谷子远缘杂交育种和谷子起源进化分析有重要意义。     

中国禾谷类作物野生近缘植物在育种中的利用

中国主要禾谷类作物有水稻、小麦、大麦、燕麦、玉米、高粱、粟、黍稷,它们的野生近缘植物在中国禾谷类作物育种中得到了较好的利用,不仅拓宽了作物的遗传基础,而且培育出优良品种在生产上大面积推广,在提高粮食产量中起到了重要作用.     

黄麻两个栽培种及其野生类型与三个近缘种的核型分析

本研究选取黄麻属（Corchorus）2个栽培品种及其4个野生类型和3个野生近缘种为材料,采用常规根尖压片法对黄麻属供试材料的染色体数目和核型进行研究。结果表明：染色体数目均为2n=14。核型公式分别为：宽叶长果（长果黄麻栽培种）2n=2x=14=14m(4SAT);南阳野生长果（长果黄麻野生类型）2n=2x=14=14m(2SAT);坦桑尼亚野生长果（长果黄麻野生类型）2n=2x=14=2M+12m;闽麻5号（圆果黄麻栽培种）2n=2x=14=12m+2sm;爱店野生圆果（圆果黄麻野生类型）2n=2x=14=14m ;廉江野生圆果（圆果黄麻野生类型） 2n=2x=14=4M+10m;假黄麻（黄麻属野生近缘种）2n=2x=14=2M+12m;假长果（黄麻属野生近缘种）2n=2x=14=2M+12m;甜麻（黄麻属野生近缘种）2n=2x=14=14m。其中除了宽叶长果核型分类为1B外,其他的都为1A型。本文还讨论了黄麻野生近缘种甜麻的分类学地位。     

十字花科栽培蔬菜及野生近缘种资源对小菜蛾的抗性分析

小菜蛾是危害十字花科蔬菜最严重的害虫,造成蔬菜产业巨大经济损失。现有育种材料中抗小菜蛾的资源非常稀缺,制约了抗虫新品种的选育。本研究利用国家蔬菜种质资源中期库中近年收集的来自10个国家,42个种,218份十字花科栽培蔬菜及野生近缘种资源进行了小菜蛾抗性鉴定。这些资源的抗性水平从极抗到极感皆有分布,除极端抗/感材料较少外,总体上呈均匀分布。属间、种间、变种间的平均抗性差异显著。同种植物的不同种质间抗性分布亦广。栽培资源比野生资源具有相对更高的平均抗虫水平,但是后者高抗材料更多。北部欧洲等地是抗性资源分布相对集中的地理区域。本研究获得抗虫资源19份,其中高抗资源4份,这些材料对蔬菜抗虫育种和抗虫基因发掘具有重要应用价值。     

中国野生稻遗传资源的保护及其在育种中的利用

我国有三种野生稻,即普通野生稻(Oryza rufipogon)、药用野生稻(O.officinalis)和瘤粒野生稻(O.meyeriana)。这三种野生稻均被列为国家二级保护植物(渐危种)。调查结果表明,野生稻由于其自然群落大量丧失而濒危,濒危程度为普通野生稻>药用野生稻>瘤粒野生稻。造成濒危的主要原因是人为的破坏活动。人类的经济活动导致了野生稻生境丧失、生境质量不断恶化、栖息地越来越少;人类的活动也导致了外来种的入侵。目前,对野生稻的保护措施主要有就地保护(原地保护或原位保护)和迁地保护(易地保护或异位保护)。易地保护包括以种子保存的种质厍、以种茎保存的种质圃和以器官培养物作为材料的超低温保存。野生稻具有许多优良特性,如特强的耐寒性、高的抗病虫性、优质蛋白质含量高、功能叶片耐衰老的特异性、特强的再生性、良好的繁茂性及生长优势等等,这些优良特性已被广泛用于水稻常规育种和杂交育种中,并取得了巨大的社会效益和经济效益。有关野生稻生物技术方面的研究,如花药培养、原生质培养、体细胞杂交和基因工程等方面已取得了较大的进展。野生稻将在水稻育种中发挥越来越重要的作用。     

In situ conservation of crop wild relatives: status and trends

Recognized as a priority three decades ago, in situ conservation of crop wild relatives has developed theoretical and methodological focus and achieved significant on-the-ground progress in the last 10 years, most notably under the impetus of the plant genetic resources community. Literature and Internet searches and interviews with experts were undertaken as a basis for reviewing the current status and trends of this effort worldwide. Country-by-country summaries on in situ crop wild relatives conservation activities are presented, and recommendations are made for future action. Principal recommendations include flagging of appropriate taxa as crop wild relatives in botanical and conservation databases, undertaking gap analyses to locate crop wild relatives hotspots, and enhancing cooperation between the plant genetic resources and plant conservation communities.     

中国粮食作物的野生近缘植物及其保存概况

中国的主要粮食作物约有20种,它们的多数都有野生近缘植物.目前,中国保存的粮食作物野生近缘植物资源约1.5万份,分别保存在国家作物种质资源库和种质圃内.     

Phenotypic and genetic diversity of leaf rust resistance in wheat wild relatives

Puccinia triticina (Pt), the causal agent of leaf rust evolves through forming new pathotypes that adversely affect the growth and yield of wheat cultivars. Therefore, continued production of resistant varieties through exploring novel sources of resistance in wild relatives which are abundantly found in Iran and the neighbouring regions is a major task in wheat breeding programs. The aim of the present study was to explore 60 wild wheat genotypes selected from the species Triticum monococcum, Aegilops tauschii, Ae. neglecta, Ae. cylindrica, Ae. triuncialis, Ae. umbellulata, Ae. speltoides, Ae. columnaris, Ae. crassa and Ae. ventricosa for resistance to leaf rust. The cultivar ‘Boolani’ and Thatcher near-isogenic lines were used as controls. Two-week-old seedlings were inoculated using 10 Pt pathotypes, and the infection types were recorded. The genotypes were also analysed for polymorphism using six sequence-tagged sites (STS) and sequence characterized amplified region (SCAR) markers. Forty-eight genotypes produced high infection types (3⁺) for two pathotypes, but the remaining genotypes produced low infection types of ‘0; ^=’ to ‘1⁺CN’ to all pathotypes. The latter included three accessions of Ae. tauschii, two accessions of each Ae. umbellulata, Ae. columnaris and Triticum monococcum, and one accession from each Ae. triuncialis, Ae. ventricosa and Ae. neglecta. Analysis for STS and SCAR markers suggested several genotypes could carry the genes Lr9, Lr10, Lr19, Lr24, Lr26 and Lr37 or their potential orthologs in addition to unknown resistance genes. In conclusion, the identified resistant genotypes could be further characterized and used in wheat breeding programs for leaf rust resistance.     

Using seminatural and simulated habitats for seed germination ecology of banana wild relatives

1. Ecologically meaningful seed germination experiments are constrained by access to seeds and relevant environments for testing at the same time. This is particularly the case when research is carried out far from the native area of the studied species.
2. Here, we demonstrate an alternative—the use of glasshouses in botanic gardens as simulated‐natural habitats to extend the ecological interpretation of germination studies. Our focal taxa were banana crop wild relatives (Musa acuminata subsp. burmannica, Musa acuminata subsp. siamea, and Musa balbisiana), native to tropical and subtropical South‐East Asia. Tests were carried out in Belgium, where we performed germination tests in relation to foliage‐shading/exposure to solar radiation and seed burial depth, as well as seed survival and dormancy release in the soil. We calibrated the interpretation of these studies by also conducting an experiment in a seminatural habitat in a species native range (M. balbisiana—Los Baños, the Philippines), where we tested germination responses to exposure to sun/shade. Using temperature data loggers, we determined temperature dynamics suitable for germination in both these settings.
3. In these seminatural and simulated‐natural habitats, seeds germinated in response to exposure to direct solar radiation. Seed burial depth had a significant but marginal effect by comparison, even when seeds were buried to 7 cm in the soil. Temperatures at sun‐exposed compared with shaded environments differed by only a few degrees Celsius. Maximum temperature of the period prior to germination was the most significant contributor to germination responses and germination increased linearly above a threshold of 23℃ to the maximum temperature in the soil (in simulated‐natural habitats) of 35℃.
4. Glasshouses can provide useful environments to aid interpretation of seed germination responses to environmental niches.

     

论我国昆虫多样性的保护与利用

本文论述了保护昆虫多样性的意义、我国昆虫多样性的基本特点及面临的问题、昆虫多样性的保护战略和利用对策。文中强调指出,昆虫是生物界的一个主要类群,在我国,需要防治的害虫大约只占全部昆虫种类数的1%,其余种类对人类都是有益或者是中性的,它们不仅可以作为显花植物的传粉者、为人类提供食物和各种工业原料,而且可以作为许多害虫或杂草的天敌,以及用于环境净化和科学研究。我国由于地域辽阔,生境复杂,因此,昆虫种类极为丰富,珍稀物种及有益昆虫较多。然而,由于受到人类活动的干扰,我国昆虫多样性面临着生境遭到破坏,物种濒于灭绝,天敌大量减少等问题。为了有效地保护和利用我国的昆虫资源,作者提出了一些战略和对策。     

Embryo rescue and plant regeneration in vitro of selfed chickpea (Cicer arietinum L.) and its wild annual relatives

The main constraint to the transfer of desired traits into cultivated chickpea from wild Cicer relatives is the presence of post-zygotic barriers which result in abortion of the immature embryo following interspecific hybridisation. Rescue of hybrid embryos in vitro and regeneration of hybrid plantlets could allow chickpea breeders to transfer desirable traits from wild relatives of chickpea. The development of embryo rescue techniques using selfed chickpea and selfed wild relatives is being used as a first step to protocols for wide hybrids. Optical microscopy studies of embryogenesis, in both selfs and hybrids, identified deleterious changes in the fertilised hybrid seed as early as 2–4 days after pollination in some crosses. These observations suggest that the appropriate time to rescue chickpea × C. bijugum hybrids is at the early globular stage of embryogenesis (2–7 days old), which requires the development of a complex tissue culture medium. In contrast hybrids between chickpea × C. pinnatifidum abort later (up to 15–20 days old) at the heart-shaped or torpedo stages, and are easier to rescue in vitro. Genotype also plays a significant role in the ability of immature selfed ovules to germinate in vitro. In this paper we report on the optimisation of␣protocols for rescueing immature embryos using selfed chickpea and its wild relatives in ovule, and subsequently to regenerate plantlets.