广西野生稻资源原生境保存探讨

农业野生植物资源原生境保存是国际植物遗传资源界推崇的一种保存方式,开展野生稻资源原生境保存,能为野生稻资源利用提供丰富的优异种质与特异基因;为稻种基础理论研究提供更广泛的遗传多样性,具有十分重大的意义。本文认真探讨广西野生稻资源原生境保存方式,保存检测技术方法及保护制度运行机制等问题,并提出广西野生稻资源原生境保存的合理化建议。     

库存野生稻种子发芽检测技术

野生稻是生物遗传多样性、水稻育种研究的重要材料。广西是我国野生稻资源十分丰富的地区之一。1978年以来,在广西农业科学院主持下,科技人员通过对广西野生稻资源普查、野外考察收集、补征和国外引种,共收集保存了近5000份（编号）野生稻种子于种质库并有5200份野生稻种茎种植于国家南宁野生稻圃保存。     

野生稻资源安全保存技术

本文介绍了野生稻资源大规模的种茎资源，种子资源的保存技术和组织培养与冷低温相结合的试验管微型种质库保存技术。为野生稻资源大规模长期安全保存，提供了可行的技术方法。     

书讯

正《作物种质资源安全保存原理与技术》主要阐述了作物种质资源安全保存的含义与范畴,系统介绍了种质库、种质圃、离体库等保存方式的种质资源安全保存的原理与技术,主要包括种子、植株、块根、块茎、茎尖、休眠芽、花粉等保存载体的寿命延长机制、活力丧失机制和遗传     

《作物种质资源安全保存原理与技术》正式出版

正本书由中国农业科学院作物科学研究所卢新雄研究员、辛霞副研究员、刘旭院士共同完成。是国内外首部作物种质资源安全保存原理与技术方面的专著,主要阐述了作物种质资源安全保存的含义与范畴,系统介绍了种质库、种质圃、离体库等保存方式的种质资源安全保存的原理与技术,可为种质资源保存、研究和设施建设提供指导,也可作为综合型大学、农林师范院     

海南普通野生稻居群植被物种多样性研究

为了摸清海南岛现存普通野生稻原生境植被物种的数量和种类,探究其植被群落物种特征,分析普通野生稻原生境伴生物种的特征特性,对海南岛境内普通野生稻(Oryza rufipogon Griff)原生境群落进行了调查和分析。通过调查,记录样地生境信息、野生稻居群大小,统计不同样点普通野生稻伴生物种种数。结果表明：海南岛普通野生稻原生境共记录植物119种,属28科。普通野生稻原生境的植被按乔木层、灌木层、草本层进行分类,乔木共计5种,分属5科;灌木层共计13种,分属9科;草本层共计101种,分属14科。原生境中物种数总体表现为：乔木层极少、灌木层较少,草本层为主的特征,其中草本层又以禾本科和莎草科植物为主。生境中外来入侵种成功入侵和人类的经济活动,共同构成了影响海南岛普通野生稻原位保护的主要因素。     

野生稻资源遗传多样性原地保存技术

野生稻是国家二级保护植物，但是其原生地却受到严重破坏，因此必须开展野生稻资源遗传多样性原地保存。本文从原生境保存地规划、保存地防护措施、原地保存的栽培管理技术和遗传多样性鉴定技术等方面论述了野生稻资源原地保存技术，为原地保存提供可靠的技术支撑。     

中国粮食作物种质资源农艺性状鉴定、编目和繁种保存概况

至１９９５年底，我国编入目录的粮食作物种质资源共２３．７万余份，其中入国家长期库保存的为２１．３万余份（含试管苗２６８３份），入种质资源圃保存的约９０００份（其中６０００份同时入长期库保存），长期库和种质圃共保存２１．６万余份     

《作物种质资源安全保存原理与技术》正式出版

作物种质资源的安全保存是其有效利用的前提,安全保存需要确保维持种质高生活力和遗传完整性。国家农作物种质资源种质库圃已经收集保存超过51万份作物种质资源,此外各省、研究机构、育种单位也保存有大量作物种质资源。然而入库圃保存并不是一劳永逸的,种质库保存的资源会面临因活力下降而丧失的风险,种质圃保存的资源易遭受自然灾害和生境恶化等威胁,也存在丧失的风险。     

《作物种质资源安全保存原理与技术》正式出版

正作物种质资源的安全保存是其有效利用的前提,安全保存需要确保维持种质高生活力和遗传完整性。国家农作物种质资源种质库圃已经收集保存超过51万份作物种质资源,此外各省、研究机构、育种单位也保存有大量作物种质资源。然而入库圃保存并不是一劳永逸的,种质库保存的资源会面临因活力下降而丧失的风险,种质圃保存的资源易遭受自然灾害和生境恶化等威胁,也存在丧失的风险。     

Characterization of common bean wild populations for their in situ conservation in Northwestern Argentina

In situ conservation of wild species is a method of conservation that allows keeping populations in their natural environments, and set the strategies for maintaining the natural populations. The Active Bank of Northwestern Argentina (BANOA) is in charge of the in situ conservation of wild populations of common bean (Phaseolus vulgaris L.) in Northwestern Argentina (NOA), and has an ex situ collection of 401 landraces and 221 wild accessions from the NOA. We evaluated the phenotypic diversity of 68 common bean wild populations from the NOA both in protected and unprotected areas, finding a moderate variation among them. Ten phenotypic reproductive characteristics related to pod and seed displayed significant differences in the analysis of variance; these traits together with the seed weight were the basis for the multivariate analysis. The cluster analysis ordered the populations in 12 groups but trends in geographical distribution or phenotypical variation were not recognized. For the conservation in situ of the wild bean populations, their diversity should be considered. Two types of populations can be highlighted: (i) candidates for in situ conservation in order to preserve the novel variation generated by convergence with cultivated sympatric germplasm (populations 433, 437, 471, 509, 513 and 517) and (ii) those whose phenotype represents clearly the wild status and should be preserved in situ as such in their current status (populations 480, 495, 496, 525 and 533).     

Genetic characterization and gene flow in different geographical-distance neighbouring natural populations of wild soybean (Glycinesoja Sieb. & Zucc.) and implications for protection from GM soybeans

To design appropriate strategies for ex situ and in situ conservation of wild soybean and safeguard the biosafety of the wild soybean gene pool when genetically modified soybeans are grown, it is important to understand its genetic characteristics, and to quantify gene flow and kinship within and between neighboring populations. We analyzed 9 pairs of neighboring populations of wild soybeans using 20 pairs of nuclear SSR markers. Results showed that Chinese wild soybean natural populations had outcrossing rates of 0–3.5% and that most populations contained many kinship families. The kinship families could be attributed to the accumulation of outcrossed offspring within populations during the history of population colonization. Wild soybean is very sensitive to environmental selection, which results in genetic differentiation of populations, and the emergence of specific alleles. We used an index τ to explain why genetic differences would exist between the pairwise populations; the interpopulation genetic differentiation chiefly consisted in the differences of allele frequencies over the genome. We found long-distance dispersal (1.5 km) of wild soybean seeds in a land ecosystem. There was close correlation between genetic and geographical distance among natural populations of Chinese wild soybean. Within a distance of 50 km, there was greater gene flow when the distance between populations was shorter. These findings have implications for ex situ and in situ conservation in an ecogeographical region, and also for protection of the gene pool from contamination by GM soybeans in wild soybean species.     

中国普通野生稻遗传多样性研究进展

普通野生稻是亚洲栽培稻的祖先,中国作为亚洲栽培稻的起源地之一,蕴藏着丰富的普通野生稻资源。为了揭示中国普通野生稻的遗传多样性分布状况,探索普通野生稻的遗传变异规律、居群遗传结构以及演化途径等,为亚洲栽培稻的起源进化研究、品种改良和普通野生稻保护提供科学依据,国内外学者对中国普通野生稻开展了大量的遗传多样性研究,获得了丰富的研究结果。本文分别从遗传多样性研究方法、普通野生稻与亚洲栽培稻遗传多样性的比较、普通野生稻遗传多样性与地理分布和生态环境的关系、保护措施和栽培稻基因渗入对遗传多样性的影响等几个方面的研究结果进行了综述,总结了中国普通野生稻遗传多样性的主要特征,提出了未来我国普通野生稻遗传多样性的研究方向。     

浙江省苍南县农作物种质资源调查与分析

为更好地挖掘、保护和开发利用苍南县重要农作物种质资源,2017年8月—2018年12月对浙江省苍南县7个镇17个行政村的农作物种质资源现状及利用情况进行系统调查,对种质资源进行收集,并对收集到的资源的种类、分布情况、植物学分类和部分特色资源进行整理和分析。结果表明,苍南县共收集到85份农作物种质资源,包括粮食作物41份、蔬菜26份、经济作物7份、果树11份,隶属于21科36属39种;按种质类型包括地方品种资源76份、野生资源9份。根据苍南县农作物种质资源现状,对苍南县地方品种和野生资源保护和开发利用进行讨论,建议通过建立资源圃和本地商业化开发利用等方式对地方品种进行原地保存,对部分地方品种或野生资源在资源采集地或原生境进行原位保护鉴定,确保本地优良种质资源的安全保存,实现种质资源可持续利用。研究结果可为苍南县农作物种质资源多样性研究、种质创新和开发利用提供参考。     

Plant breeding: past,present and future

Plant breeders can help farmers increase food production by breeding new cultivars better adapted to their chosen farming systems, but these must be capable of providing the necessary plant inputs for the required levels of crop production in 2050. Until 200 years ago the farmers themselves were the plant selectors. Plant domestications, extensive crop dispersions and farmers’ selections produced thousands of locally adapted landraces of cultivated plants. During the twentieth century these were largely replaced by relatively few high yielding cultivars and the natural habitats of many of their wild relatives became endangered. Hence in situ and ex situ conservation, and evaluation and use of plant genetic resources is vital for future plant breeding. The development of scientific breeding from the beginning of the twentieth century was based on understanding the mechanism of inheritance and the mating systems of crop plants. The types of genetically uniform, high yielding cultivars that have been bred from genetically heterogeneous landraces were determined by the mode of reproduction and mating system of the cultivated plant species: inbred line (wheat) and hybrid (rice) cultivars for inbreeding species, hybrid (maize) cultivars for outbreeding species, and clonal (potato) cultivars for vegetatively propagated species. When genetically heterogeneous crops are desired, mixtures of cultivars and synthetic cultivars can be produced. Future progress in crop improvement will come from three complementary approaches: use of hybridization and selection in further conventional breeding, base broadening and introgression; mutation breeding, cisgenesis and gene editing; and genetically modified crops.     

库存玉米种质资源发芽力监测与分析

为给种质库贮藏玉米种质及其他作物种质发芽力监测、方法制定及安全保存期限的确定提供科学依据。对种质库中8种不同入库编号1729份的玉米种质资源取样进行发芽势和发芽率监测并将结果与入库前的发芽数据进行比较分析。结果表明,贮藏27~32 年后,种子平均发芽势为82.66%,平均发芽率为88.09%,有86.58%以上的种子发芽率仍保持在75%以上,但有73 份种子发芽率已降至50%以下;贮藏31~32 年的种质发芽率下降明显,而贮藏27~30 年的种质平均发芽率下降不明显。不同原产地的玉米种质经31 年长期贮藏后发芽率下降不同,原产广西地区种质比原产区外、国外引种种质发芽率高。不同年份贮藏的玉米种质资源或同一年份贮藏的不同原产地的玉米种质资源经低温长期保存后发芽力下降趋势不同,玉米种质资源长期库的安全保存期限可达30年以上。     

Genetic diversity and population structure of ‘Khao Kai Noi’, a Lao rice (Oryza sativa L.) landrace,revealed by microsatellite DNA markers

Rice (Oryza sativa L.) is the main food for people in Laos, where it has been grown and eaten since prehistory. Diverse landraces are grown in Laos. ‘Khao Kai Noi’, a landrace favored for its eating quality, is held in the nationwide collection of traditional landraces in the Lao national genebank. Genetic diversity is crucial for sustainable use of genetic resources and conservation. To investigate the genetic diversity of ‘Khao Kai Noi’ for conservation, we genotyped 70 accessions by using 23 polymorphic simple sequence repeat markers. The markers generated 2 to 17 alleles (132 in total), with an average of 5.7 per locus. The total expected heterozygosity over all ‘Khao Kai Noi’ accessions was 0.271. Genetic variation was largest among accessions and smallest within accessions. Khao Kai Noi accessions were classified into three different genetic backgrounds, but there was unclear association between the three inferred population and name subgroups and geographical distribution. Most of the accessions were clustered with temperate japonica and showed genetic relatedness to rice from neighboring provinces of Vietnam, suggesting a Vietnamese origin. The results of this study will contribute to the conservation, core collection and future breeding of the Khao Kai Noi population.     

Strategies for conservation of genetic resources in relation with their utilization

The general interest for genetic resources is based on the opportunities offered by their utilization. Genetic resources are a necessary starting point for plant improvement. Up to now, reflection on the management of genetic resources considered a three-step linear model: conservation → evaluation → utilization. In this system, it is expected that genetic resources are kept in a gene bank, in the best possible way, i.e. using methods maintaining over time the initial genetic state of the accessions and conferring them the longest life possible. In this system, important characteristics of conservation of genetic resources are stability and availability. We present a choice of methods of conservation directed to the maintenance of genetic stability of accessions. We also present methods of conservation in relation with the availability of the genetic material for the various utilizations by the plant breeder. Complementary methods are now proposed for the conservation of genetic resources. These methods correspond to a modified version of the linear model, with interactions between conservation, evaluation and utilization. These new methods place less emphasis on the conservation of genetically well defined accessions but promote genetic mechanisms allowing evolution of these accessions. This evolutionary conservation is obtained by management of experimental populations, or by on-farm management of landraces, relying on knowledge and activity of farmers, and on local breeding. For the wild relatives of crops, an in situ management is to be considered. Using some examples, we discuss the constraints of these new modes of genetic resources conservation and utilization. This revised version was published online in July 2006 with corrections to the Cover Date.