Effects of Baking and Boiling on the Nutritional and Antioxidant Properties of Sweet Potato [<Emphasis Type="Italic">Ipomoea batatas</Emphasis> (L.) Lam.] Cultivars

The effects of baking and boiling on the nutritional and antioxidant properties of three sweet potato cultivars (Beniazuma, Koganesengan, Kotobuki) cultivated in Turkey were investigated. The samples were analyzed for proximate composition, total phenolic content, ascorbic acid, β-carotene, antiradical activity, and free sugars. The dry matter, protein, and starch contents of the sweet potatoes were significantly changed by the treatments while the ash and crude fiber contents did not differ as significantly. The β-carotene contents of baked and boiled sweet potatoes were lower than those of fresh sweet potatoes; however, the total phenolic and ascorbic acid contents of the baked and boiled sweet potatoes were higher than those of the fresh samples. Generally, the antiradical activity of the sweet potatoes increased with the treatments. Sucrose, glucose, and fructose were quantified as free sugars in all fresh sweet potatoes; however, maltose was determined in the treated samples. In terms of the analyzed parameters, there were no explicit differences among the sweet potato cultivars.     

内蒙古西部区马铃薯脱毒种薯快速繁育的研究——Ⅱ.脱毒种薯生产技术及其良种繁育体系的研究

在内蒙古乌兰察布盟后山地区武川原种基地，对各级种薯生产技术及其良繁体系进行了系统的研究。现已明确：在开放条件下生产脱毒小薯（原原种），产量可达８０７３～９４６５ｋｇ／ｈｍ２，种薯产量和质量不低于温、网室生产的脱毒小薯；不同薯重的脱毒小薯旱坡地直播效果，以１０ｇ和８～１０ｇ薯重的效果好，产量和商品率均高；１级种薯在不同旱地类型种植的增产效果，以旱滩地的产量最高，其次为旱坡地，分别比对照（未脱毒）增产７１．２８％、１７１．２８％；８月上旬为有翅桃蚜迁飞盛期，从７月上旬迁飞初期开始喷药防蚜，防治效果显著；在乌盟后山半农半牧地区以原原种、原种、１、２级种薯建立的３级脱毒良种繁育体系符合该地区的生产实际，能达到留种和保种的快速、优质、高产、低成本的效果。经过６年示范推广，现已在武川等３个旗县普及，累计各级种薯种植面积达到２．３２万ｈｍ２，平均单产３万ｋｇ／ｈｍ２左右，生产出各级种薯及商品薯６９８５万ｋｇ，累计创造社会财富７１５０万元。     

Potato viruses in China

Potato (Solanum tuberosum L.) is globally the fourth largest staple crop after rice, wheat and maize. China is the largest potato producer worldwide, accounting for 26.3% and 22.2% of the global total area and yield, respectively. Viral diseases have been a limiting factor for sustainable production of potato in China. This article provides update and comprehensive information on the most important viruses, their effect on yield and their control in China. Meristem culture is currently the most widely used technique for production of virus-free potato plants and these plants are used as nuclear stock for the production of certified seed tubers. Although a significant increase in tuber yield has been achieved using certified seed potatoes, lack of application of a national seed potato production scheme has hindered progress. Conventional breeding using virus-resistant cultivars introduced from other countries as parents has already led to the production of Chinese cultivars. Use of virus-resistant wild Solanum species and genetic transformation techniques will provide new virus-resistant varieties in the future to further enhance control of potato viruses in China.     

Analyzing genotype by environment interaction in potato using yield-stability index

The plant breeding program of the National University of Colombia carried out 10 potato regional trials during 1998 and 1999 to evaluate 15 promising potato clones (Solanum tuberosum ssp.andigena). Genotype by environment interaction was analyzed using Kang’s methodology, which links yield performance and phenotypic stability. A MACRO was implemented using the SAS system to obtain yield-stability indices. Shukla’s variance was estimated by restricted maximum likelihood (REML), which allowed handling unbalanced data for both genotypes and replicates. In addition, a multivariate analysis methodology was developed, based on the yield-stability index. This methodology is useful when tuber yield is categorized by size and quality, which is usual in Colombian potato harvests.     

Seed Potato Production in Poland

The aim of this research was to analyze the regional distribution and quality of potato seed production in Poland from 2007 to 2011. The research was based on 10,559 tuber samples taken for the official post-harvest inspection assessment of seed potato lots. A very detailed map of seed plantation locations in Poland was created at the municipality level. The greatest concentration of seed production was from the northern and southern parts of Pomorskie Province, where many seed potatoes were cultivated, and in the north of the Zachodniopomorskie Province, around the towns of Koszalin and Ko?obrzeg. In both provinces, cultivars which were highly susceptible to PVY were cultivated on nearly half of the area. Over time a clear increase in the production of elite material and a decrease in those certified as the lowest category, CB, were observed. The quality of seed potato material was poorest following the harvest in 2008, because of high levels of virus infection; 30 % of the seed lots were not certified. Potato leaf roll virus (PLRV) was recorded occasionally and it is at present of no economic importance in Poland. The role of potato virus Y (PVY), increased, probably because of the growth in the share of foreign cultivars (mainly Dutch) which are more susceptible to PVY. There were also changes in the populations of PVY strains. The share of Polish cultivars in potato seed production decreased to 36.3 % in 2012.     

黑龙江省马铃薯种植区划的研究

黑龙江省是我国主要的马铃薯产区,也是国家种薯和商品薯生产的重要基地之一。合理的种植区划与生产布局对发展我省的马铃薯生产,提高种薯和商品薯的质量是非常必要的。黑龙江省地域辽阔,各地所处地理位置、地势地貌、土壤与气候等适生条件的不同,以及社会经济条件综合因素的作用,都影响着马铃薯的分布和生产。依据马铃薯的生物学特性的要求和各地自然条件的分异规律以及社会经济条件等因素,把我省马铃薯的种植划分为北部最适宜区、南部适宜区、西部次适宜区和东部次适宜区。     

The Use of True Potato Seed as Pro-poor Technology: The Efforts of an International Agricultural Research Institute to Innovating Potato Production

The International Potato Center (CIP) and collaborating institutions implemented an intensive research programme over a period of 25–30 years on the use of botanical seed of potato as an alternative way of growing a potato crop. The use of botanical or ‘true’ potato seed (TPS) had many advantages over the use of seed tubers. Potentially, the use of TPS was especially attractive for small-scale farmers in developing countries. The difference of using TPS as compared to using seed tubers meant in many respects the development of a new crop–commodity chain, requiring research on breeding, seed production, agronomy and marketing aspects. This research made it possible to produce potatoes from TPS at commercial scale: it removed a number of important constraints in the uniformity and earliness of the TPS varieties and in seed physiology. Experimentation and adoption by farmers in a wide range of countries showed that the technological advantages of using TPS were only translating in economical benefits as compared to tuber seed when the last one was costly or not available. Since the economic performance of seed tubers is likely to continue to fluctuate, TPS remains an interesting alternative. Study of the use of TPS in various countries could contribute to better understanding of factors that promote or inhibit crop technology innovation. The article gives an overview of the various areas of TPS research in CIP and presents information on the application of TPS technology in several developing countries.     

北京地区马铃薯就地留种措施的试验

本试验结果证明,采取马铃薯春播早收,拔除病株,选用合适的品种,实行二季作秋播留种等措施,可以实现北京地区就地留种的目的。采用上述措施后,“京丰1号”和“张北78-1-34”留种4～5年,仍可取得较高产量。     

Colorado potato beetle resistance management strategies for transgenic potatoes

NewLeaf potatoes could provide substantial ecological and economic benefits to potato growers. A concern with NewLeaf potatoes, however, is that Colorado potato beetle may develop resistance to the Bt endotoxin because of the intense selection pressure imposed by its constant presence in the transgenic crop. Before these cultivars were released, however, entomologists throughout North America conducted biological research needed for a strategy to prevent or delay resistance in Colorado potato beetle. This paper describes the considerations and research behind the proposed strategy. Because NewLeaf potatoes express a relatively constant and high concentration of Bt endotoxin throughout the foliage of each plant, reducing selection for resistance must come from planting standard potatoes as a refuge for susceptible beetles. Avoiding resistance through random mixtures of NewLeaf and standard potatoes was evaluated in laboratory and field studies. The conclusion from this research was that the seed mixture would not provide an effective refuge. The most effective alternative refuge was judged to be a block of standard potatoes planted in the same field as the NewLeaf potatoes. By allowing susceptible beetles to survive in their fields, potato growers might sustain the benefits of very effective controls.     

The Value of Seed Potatoes from Four Systems in Kenya

Although potatoes are the second most valuable crop in Kenya, poor seed potato quality has limited industry expansion. The objectives of this study were to describe the seed potato system, identify problems, determine use of high-quality seed and estimate farmer willingness to pay (WTP) for different types of seed. Data was collected from interviews, forums and surveys. A contingent valuation method (CVM) model was also developed to analyze the factors that influence farmer WTP. It was found that the seed system consists of three sub-components: Formal, Semi-Formal and Farmer. More than 96 % of Kenya seed potatoes were produced in the Farmer category, and were considered to be poor quality. Growers identified bacterial wilt, viral diseases and late blight as the most serious problems. The WTP model revealed that farmer age, distance to seed source, potato training, gender and region were statistically significant explanatory variables. The study recommends that training be conducted to increase production of “clean seed” and “positively-selected seed” in the Semi-Formal part of the seed system.     

Seed Potato Quality Improvement through Positive Selection by Smallholder Farmers in Kenya

In Kenya, seed potato quality is often a major yield constraint in potato production as smallholder farmers use farm-saved seed without proper management of seed-borne pests and diseases. Farm-saved seed is therefore often highly degenerated. We carried out on-farm research to assess whether farmer-managed positive seed selection could improve yield. Positive selection gave an average yield increase in farmer-managed trials of 34%, corresponding to a 284-€ increase in profit per hectare at an additional production cost of only 6 €/ha. Positive selection can be an important alternative and complementary technology to regular seed replacement, especially in the context of imperfect rural economies characterized by high risks of production and insecure markets. It does not require cash investments and is thus accessible for all potato producers. It can also be applied where access to high-quality seed is not guaranteed. The technology is also suitable for landraces and not recognized cultivars that cannot be multiplied formally. Finally, the technology fits seamlessly within the seed systems of Sub-Saharan Africa, which are dominated by self-supply and neighbour supply of seed potatoes.     

The potential for production of high quality seed potatoes in Tierra del Fuego Island, Argentina

Summary In Argentina, different areas are suitable for seed potato production: however, each has particular problems, mainly related to different pest and diseases. Tierra del Fuego Island is well isolated from traditional potato growing areas. Therefore, it was tested for its potential for seed production. The cultivars Achatt. Mailén INTA. Pampeana INTA and Spunta were grown in Río Grande, San Pablo and Ushuaia from 1991–1994. Nematode presence and aphid population dynamics were recorded. Average tuber yield ranged from 20.1–37.6 t ha⁻¹. After three years PVY and PLRV remained low (0–1% for different cultivars and locations). Moreover, seed tubers obtained were physiologically young. Long days, early frosts and strong winds may limit tuber yield in some years. The island can be considered as an ecological “safe haven” and is very suitable to obtain healthy and physiologically adequate seed potatoes.     

Comparison of inoculation methods for field studies on varietal response to verticillium wilt of potatoes

Verticillium albo-atrum, cultured on potato dextrose agar plates or on sterilized wheat kernels, was used to incite disease in field studies. Immediately prior to planting, seed potatoes were dipped in a spore/mycelium suspension that was prepared from agar plate cultures. A second inoculation treatment involved placing infested wheat kernels under the potato seed at planting time. Both inoculation methods resulted in verticillium wilt development. However, the inoculum suspension dip method resulted in slightly greater incidences of verticillium wilt than did the infested wheat method. Inoculation by means of a suspension dip immediately after cutting the seed resulted in more wilted plants than when seed was inoculated 24 hours or 7 days after cutting. The spore/mycelium suspension dip method is now routinely used for field studies on disease susceptibility or resistance in potato cultivars.     

Potato production in Sri Lanka

Potato production in Sri Lanka has been increasing since the importation of tablestock was stopped in 1967. Production is now successfully established in four regions: Nuwara Eliya, Badulla, Jaffna and Puttalam. Average yields areca. 16 T/ha but can reach as high as 40 T/ha. Production still depends on the importation of seed potatoes which are then multiplied under a government program. In order to reduce the cost of seed, which can be up to 50% of the cost of production, a true seed program has been instituted. Weather, poor storage conditions, varying availability of good seed and diseases are the major problems limiting potato production in Sri Lanka. Significant reductions in production and storage problems will be realized with the continued efforts of the Sri Lankan government and international agencies.     

Seeds for the Future = Challenges for Potato

The quality of seed potatoes is of paramount importance. The Netherlands and France are important seed potato exporters. In France, seed potato production is a well-organised and economically important sector in which genetic crop improvement and advancement of seed health are crucial objectives. There are strong debates in France on the use of new breeding techniques, which require special skills, equipment, facilities and investments, but which are not always accepted by the general public. The seed potato sector should prepare itself for a situation in which pests and diseases will adapt themselves to global change. Moreover, pests and diseases may thrive under the reduced use of chemical crop protectants. In this regard, it is essential to assess which multiplication techniques will have a better future: are we going to grow potatoes on the basis of seed potato schemes or on the basis of true potato seed? At the same time, there are many national and international changes in legislation about seed production. The seed potato sector must prepare itself for a diverse set of changes in a very dynamic world.     

Genetic Resources (Including Wild and Cultivated Solanum Species) and Progress in their Utilisation in Potato Breeding

The genetic resources available for the improvement of the cultivated potato (Solanum tuberosum) are reviewed along with progress in their utilisation. The conclusions are as follows. The wild and cultivated species of potato have been utilised in potato breeding to good effect, but only a very small sample of the available biodiversity has been exploited. New knowledge and technology will open possibilities for much greater use of these genetic resources in breeding. The strategy for utilising the cultivars native to Latin America will either be the introgression of desirable genes or the direct use of parents from improved populations, depending on how far modern S. tuberosum cultivars have genetically diverged from them and the extent to which S. tuberosum cultivars have been improved in the process. Molecular marker-assisted selection will be used for faster introgression of desirable genes from wild species, and the possibility exists of moving genes directly from wild species to cultivated potato with transgenic methods. New cultivars will continue to come from crosses between pairs of parents with complementary features but adapted to local growing conditions. However, increasingly these parents will possess desirable genes which have been introgressed from wild species and may also be from complementary groups of cultivated germplasm to exploit hybrid vigour. Successful cultivars may be genetically modified, if consumers see benefits in the use of the technology, to introduce genes not present in cultivated potatoes and their wild relatives to achieve novel biochemistry and further desirable improvements.     

河北省一季作区马铃薯病虫害发生及综合防控

河北省一季作区马铃薯主要病虫害有晚疫病、早疫病、黑痣病和二十八星瓢虫,此外,病毒引起的品种退化比较普遍,造成不同程度的损失。本文根据河北省一季作区马铃薯病虫害发生特点总结出一套综合防控技术体系,包括将马铃薯与玉米、大白菜等非茄科作物轮作3年减轻黑痣病危害;采用脱毒薯克服病毒引起的品种退化问题;种薯和(或)土壤消毒控制黑痣病和晚疫病;待马铃薯生长至封垄后,遇到适宜晚疫病发生的天气,喷施1～3次保护性杀菌剂预防晚疫病和早疫病;一旦监测到晚疫病中心病株后即拔除并装入塑料袋带出田外,并交替喷施有治疗效果、能兼治早疫病且作用机制不同的内吸性杀菌剂及混剂;田间出现马铃薯二十八星瓢虫成虫,在杀菌剂中混入高效氯氰菊酯或高效氯氟氰菊酯等高效杀虫剂防虫;马铃薯成熟前1～2周将地上部分割掉并运出田外后收获块茎。     

晋西南山区马铃薯品种比较试验

为了适应晋西南山区马铃薯产业发展中不同区域、不同种植模式对种薯的不同要求,2010年对引进的12个马铃薯品种进行品种比较试验。从各参试品种的生育期、农艺性状、丰产性、抗病性等方面进行分析比较,筛选出了中熟品种中薯9号,早熟品种费乌瑞它、中薯5号3个优良品种在该区域推广。     

Current status of the TPS technology in the world

Summary The availability of improved True Potato Seed (TPS) varieties for short and long photoperiod conditions has recently increased the interest in the TPS technology. A summarized overview is presented of the TPS technology for potato tuber production, TPS breeding and production. TPS competes successfully with clonal cultivars in Egypt and India. In other developing countries higher yields and better adaptation are needed to make the TPS technology economically attractive; the case of TPS in Indonesia is used to illustrate this. In industrialised countries, well-performing seed tuber programmes, productivity and legislative restrictions are difficult to beat by TPS. However, the use of TPS can be economically attractive where disease pressure is high. It is concluded that TPS has a place within potato systems where agroecological conditions for seed tuber systems and steady supply of good quality tubers from a formal seed programme are most constrained. Further genetic improvement will increase the areas where TPS provides better and cheaper planting material.     

云南省宣威市马铃薯晚疫病发病规律研究

本研究用定点观察的方法,连续3年对云南省宣威市马铃薯种植田块中田间气候、种植习惯、品种等因素进行调查记录,同时观察记录该区域马铃薯晚疫病田间发生、发展情况。结果表明:马铃薯疫病在云南宣威市的发生与流行受主栽品种的抗性、种薯带菌率以及田间气候条件等多因素综合影响。新品种滇薯6号在当地表现出较好的抗性;种薯带菌率越高,田间晚疫病发生越重,流行越快;田间相对湿度高,对晚疫病发生与流行十分有利。