Potato germplasm collecting expedition to the Guaitecas and chonos Archipelagos,Chile, 1990

Summary A joint Chilean, Italian, and United States potato (Solanum tuberosum) germplasm collecting expedition was conducted in the Guaitecas and Chonos Archipelagos, south of Chiloé Island, between March 4 – March 21, 1990. The expedition resulted in 30 collections ofSolanum tuberosum and 1 collection ofFragaria chiloensis L. Twenty-three of the potato collections were along the salt-water-swept shores of the islands. These beach populations, unlike the indigenous landraces in southern Chile, are self-perpetuating populations and provide useful new germplasm for researchers interested in the origin of cultivated potatoes and in the origin ofSolanum tuberosum in Chile.     

Potato germplasm collecting expedition to Chile, 1989, and utility of the Chilean species

A joint Chilean, United States potato (Solanum sect.Petota) germplasm collecting expedition was conducted in Chile between January 21–March 30, 1989. The trip resulted in collections ofSolanum brevidens (50 accessions),S. etuberosum (28 accessions),S. maglia (3 accessions) and indigenous primitive landraces ofS. tuberosum (24 accessions). Comments are presented on the habitats, distribution, and potential and realized breeding value of these species.     

Mexico, 1988 potato germplasm collecting expedition and utility of the Mexican potato species

A joint Danish, Mexican, United States wild potato (Solanum sect.Petota) germplasm collecting expedition was conducted in Mexico between Aug. 21-Oct. 20, 1988. The trip resulted in 93 seed and 25 tuber collections of 18 species and one putative natural hybrid,S. xmichoacanum. Rare species collected include:Solanum darum,S. hintonii,S. lesteri, andS. xmichoacanum. First germplasm collections were made of the disjunct populations ofS. fendleri from Baja California. The potential and realized breeding value of these species is discussed.     

Wild potato (Solanum sect.Petota) germplasm collecting expedition to Argentina in 1990, and status of Argentinian potato germplasm resources

Summary A joint Argentina/United States expedition collected wild potato (Solanum sect.Petota) germplasm in Argentina between February 4–28 and March 28–April 18, 1990. This was followed by a short expedition between February 27 and March 3, 1991. Collections were made in the Andes Mountains from southern Tucumán Province (27°20′S), south to southern Rio Negro Province (40°52′S) and comprised 88 lots of germplasm of ten species, 76 as true-seed and 12 as tubers. The most important new collections included germplasm ofS. brevidens, S. maglia, S. x rechei andS. venturii. By summarizing details of these collections with those of existing collections, we have been able to suggest future collecting in Argentina.     

Wild potato (Solanum sect.Petota) germplasm collecting expedition to Mexico in 1993, with special reference toSolanum bulbocastanum Dunal andS. cardiophyllum Lindley

Summary A joint Mexico/United States expedition collected wild potato (Solanum sect.Petota) germplasm in Mexico between August 1–31, 1993. The purpose of the expedition was to expand germplasm and herbarium collections ofS. bulbocastanum andS. cardiophyllum. Collections were made from west-central to southern Mexico, and comprised 19 true seed and 37 tuber collections (45 collections in total) of 9 species and two putative natural hybrids.     

Potato germplasm resistant to corky ringspot disease

Potato germplasm was assessed for resistance to corky ringspot disease (CRS) incited by transmission of tobacco rattle virus (TRV). TRV is transmitted by the stubby root nematode,Paratrichodorus allius, in the Pacific Northwest, and characterized by necrotic areas in the tuber. Four tests were conducted at two different problem fields in Umatilla, OR and Pasco, WA. The fields differed in the virulence of the virus isolates. Some clones and named varieties showed resistance only in the field with the relatively mild Umatilla isolate, while others remained symptomless at both sites. The host suitability of test potatoes to threeP. allius populations from the region was determined in greenhouse pot tests, and expressed as reproductive values [R_f = (final population of nematode at 55 days) / (initial population)]. TheR _f values for the nematodes were not correlated with resistance ratings based on visual scoring of CRS symptoms in field grown potatoes. Thus, it appears that CRS resistance is based on reaction of potato genotypes to virus and not the vector. The availability of resistant clones inin vitro form is indicated.     

Potato minitubers: Technology validation in Mexico

The effects of four previously reportedin vitro tuber-inducing modified culture media on the potato cultivars Atzimba and Juanita were studied under three illumination regimes. Tuberization from stem segments started 7–18 days after transfer for all the cultivar-light-medium combinations, but this early start was not related to tuber yield. Atzimba tuberized more than Juanita (1.0 and 0.8 tubers/plant respectively), and 8 h light was optimal. The medium by Wang Hu (WH) promoted the greatest tuberization for cultivar Atzimba (1,198 mg/plant) and that by Palmer-Smith (PS) for Juanita (290 mg/plant). The modified Stallknecht’s (ST), on the contrary, slightly stimulated tuberization under all illumination conditions. The presence of cytokinins and light favored the tuberization process. Dormancy was not observed in any of the microtubers, regardless of the tuber-inducing treatment.     

Solarium SectionPetota in Costa Rica: Taxonomy and genetic resources

Prior to 1996, worldwide holdings of germplasm of wild potatoes from Costa Rica amounted to just two collections; this country therefore formed a priority for collecting. We mapped all localities of wild potatoes from herbarium specimen data from Costa Rica and collected throughout the country. We made 13 collections, 10 of these with botanical seeds. These collections considerably extend the numbers of accessions and geographic range of the germplasm available from Costa Rica. The taxonomic identity of the species of wild potatoes (Solanum sect. Petota) in Costa Rica was previously unresolved. Our fieldwork supports the concept that Costa Rican wild potatoes belong to a single species,S. longiconicum.     

中国芝麻种质资源研究：Ⅱ.保存与更新

１９８６－１９９５年共繁殖芝麻种４２５１份送交国家种质库长期保存,并建立了复份种子中期库。同时各省市区也分别保存了本地区的资源。在自然条件下芝麻种子超干燥贮藏（种子含水量为２％左右）,有效保存期可达１７￣２０年,干燥器具有超干燥、中长期保存芝麻种子的良好效果,采用非隔离种植方式,辅以田间去杂提纯、花期化学杀虫等措施,能有效地保持芝麻亲子代遗传相似性。在正常条件下,一般种植群体的有效株率占５０％,群     

甜菜种质资源的繁种更新

繁种更新是种质资源保存过程中遇到的必然问题。甜菜作为二年生异花授粉作物更容易发生变异。要保持群体的遗传完整性，其繁种更新技术相对更难。本文试从甜菜的遗传特性入手，对繁育过程中容易产生的遗传漂变和遗传漂移等诸多因素进行了讨论。     

Potato germplasm with combined resistance to leafroll virus and viruses X and Y

Potato germplasm with high levels of combined resistance to potato viruses X, Y, and leafroll was identified and used to produce improved parental clones with similarly high levels of resistance. Resistance was determined from the amount of tuber infection following inoculation of plants in the field. Parental germplasm with the best multiple resistance came from two backgrounds, eitherSolanum tuberosum group Andigena derived from the Cornell University neo-tuberosum program, or from complex hybrids ofS. tuberosum and wild solanums that were produced by the Max Planck Institute and the Polish Institute for Potato Research. Two Aberdeen, ID selections, A85519-6 and A85530-10, with gp. Andigena ancestry, have had no tuber-borne infection of PVX, PVY, or PLRV during four years of intensive field testing. We have not been successful in combining virus S resistance with resistance to the other viruses.     

我国枇杷种质资源与育种的研究进展

从枇杷的起源、系统分类和品种鉴定等方面综述了我国枇杷的种质资源研究现状;介绍了枇杷的引种、选种、育种等方面的研究进展。     

Potato genetic resources: Sources of resistance and systematics

The major potato of commerce,Solanum tuberosum L., is the fourth most important food crop in the world after rice, wheat and corn. Fortunately, the potato has many primitive cultivars and wild species relatives useful to reduce our reliance on chemical controls. These include resistances against diseases, pests, and traits for useful agronomic characters such as yield, specific gravity, chipping qualities, and suppression of enzymatic browning. This paper summarizes some of these qualities, and provides an overview of germplasm availability and taxonomy of the wild species. The major potato of commerce,Solanum tuberosum L., is the fourth most important food crop in the world after rice, wheat and maize. It is grown in more countries than any other crop but maize, and forms the staple crop of many societies. Over 280 million metric tons were grown worldwide in 1989, with Eastern Europe growing 46%, Asia 22%, Western Europe 17%, North America 7%, Latin America 5%, and Africa 3% (2). It is the leading vegetable crop in acreage and farm value in the United States, with 1.2 million acres planted in 1991, with a value of sales almost two and one-half billion dollars (53).Solanum tuberosum is one species of a group of seven cultivated and 216 additional tuber-bearing, and nine non-tuber-bearing wild relatives, all classified by Hawkes (41) in the genusSolanum, sectionPetota Dumort The purposes of this paper are threefold: 1) to provide examples of the proven and potential utility of wild and cultivated landrace members of sect.Petota for reducing our reliance on chemical controls for many pests and diseases that affect commercial cultivars, 2) to provide an overview of the status of germplasm availability of these species, and 3) to highlight the benefits for continuing germplasm collections and systematic studies of the group.     

亚麻品种资源的聚类分析及评价

对52个国内亚麻品种进行聚类分析,形成了亚麻品种的系统分类,亚麻可分为4个品种群.其中品种群Ⅱ包含两个亚群,亚群Ⅰ为油用及油纤兼用类型,亚群Ⅱ为纤维用类型.亚群Ⅱ包括了我国主要栽培品种,这些品种抗病性强,产量水平高,农艺性状优良.品种群Ⅵ的明显特点是主茎分枝多,单株果数多,抗病性强,其中红木65和匈牙利5号为我国品种选育的骨干亲本.     

分子指纹图谱技术及其在茶树品种资源中的应用

随着各种新型DNA分子标记的出现,带动了DNA指纹图谱技术的快速发展。本文简要阐述了几种常见DNA指纹鉴定技术,如限制性片段长度多态性(restriction fragment length polymorphism,简称RFLP)、随机扩增多态性DNA(random amplified polymorphic DNA,简称RAPD)、扩增片段长度多态性(amplified fragmentlength polymorphism,简称AFLP)、简单重复序列或微卫星标记(simple sequence repeat,简称SSR)、内部简单重复序列(inter-simple sequence repeat,简称ISSR)和单核苷酸多态性(single nucleotide polymorphisms,简称SNPs)等的基本原理、在技术上的优缺点及其在茶树品种资源中的应用,包括品种的鉴定、纯度的检测、品种亲缘关系与分类的研究及品种专利权的正当维护等。同时,对DNA指纹图谱技术在应用中的存在问题及相应的解决途径进行了简单的讨论,如目前DNA的提取方法与育种应用的大规模群体不相适应和大多数DNA指纹图谱检测技术仍比较繁琐,限制了该技术在育种中的大规模应用等。