Such areas will usually be geographically and climatically less favorable to the aphid vectors of viruses which cause systemic infection Jeffries et al. Meristem culture and micropropagation have now become routine in seed certification schemes and have been reviewed by Wenzel and Veilleux Meristem-tip culture can be used in combination with thermotherapy and chemotherapy to eliminate viruses.
Rooted plantlets are indexed for virus testing and the virus-free plants are increased by clonal multiplication, starting with in vitro axillary node and shoot production. The resulting axillary plants can be used to produce nodal cuttings for in vitro production of microtubers, greenhouse production of minitubers, and for rooting in soil and transplanting to the field. Field generations of multiplication need to be kept to a minimum to maintain high seed health.
It is common practice for the Certifying Authority to hold in vitro pathogen-free nuclear stocks of cultivars under multiplication. Finally it is important to point out that strict quarantine procedures are required when potatoes are transferred from one country to another to prevent the introduction of diseases, particularly non-indigenous ones. Again advances with in vitro techniques are proving useful.
There are, however, circumstances where cultivars based on current methods of true potato seed TPS propagation are an attractive proposition. In the torrid zones of the lowland tropics and subtropics the difficulty of establishing a TPS crop, later maturation and less uniformity can be outweighed by three advantages Golmirzaie et al.
Seed costs Potato Origin and Production 17 are reduced due to the much smaller amounts of planting material required. Planting time is flexible because the farmer does not have to consider the physiological age and condition of seed tubers. Finally, tubers are free from tuber-borne diseases with the possible exception of the few caused by true seed-borne viruses.
Chilver et al. Breeding cultivars for TPS was in fact started back in by CIP with the aim of high yields and acceptable uniformity. This latter trait is important because none of the current breeding methods can deliver genetic uniformity Golmirzaie et al. While TPS can be propagated by direct drilling and transplanting, preference is now given to rapid multiplication by cuttings or shoot-tip culture to give first-generation tubers or mini-tubers that can be chitted before planting Simmonds, Methods involving multiplication allow some selection to be practiced within a TPS progeny, and hence are a compromise between vegetative and true seed multiplication.
Synthetic seed is an alternative to TPS that would avoid the need to develop parents that generate uniform hybrids. Hence there is currently renewed interest in somatic embryogenesis in potato, and sufficient progress has been made for serious consideration to be given to exploiting synthetic potato seed, as seen in the review by Veilleux The same is true for post-harvest management and controlling the many pests and diseases of potato.
The interested reader is referred to the books edited by Gopal and Khurana and Vreugdenhil It is, however, worth recalling that the modern fertilizer industry began in the middle of the 19th century and was well established by the end of that century. Likewise, the 19th century saw the start of progress in the chemical control of pests and diseases, but it was the middle of the 20th century onwards that saw the systematic search for new compounds and the establishment of the agrochemical manufacturing of herbicides, insecticides and fungicides Spedding, Further increases in stable potato production are certainly going to be needed to meet increased demand for food from population growth, particularly in Asia, Africa and Latin America, during a period of climate change.
In the early 19th century potatoes were stored in unventilated clamps, and still are in some countries for short-term storage of ware potatoes Gottschalk and Ezekiel, Potato stores with outside-air cooling systems were first constructed in the s for long-term storage of large quantities of tubers. Stores with electronically controlled environments have been developed since the s, with refrigerated storage the best option for long-term storage.
The purpose is to maintain quality as long as possible with minimum losses, particularly weight losses from respiration and transpiration. However, low-temperature storage is not suitable for potatoes meant for chips crisps or French fries chips because low temperatures cause sweetening in most varieties as a result of excessive reducing sugar accumulation.
This results in discoloration during frying and acrylamide formation from the Maillard reaction between asparagine and reducing sugars. As there is evidence that acrylamide may be directly or indirectly carcinogenic, processors are under pressure to lower acrylamide concentrations in their finished products, and to this end varieties with lower reducing sugar concentrations could help Kirkman, ; Storey, This should be feasible either by conventional breeding or through transgenic approaches.
Potatoes for other uses are stored at intermediate temperatures. During the last years potato processing has grown into a global industry which expanded rapidly after the Second World War — and is still expanding.
The first European reference Burton, to dried potato was by Parmentier in France in in the form of biscuits made from boiled potatoes for use by sailors. He also discussed methods of drying cooked potatoes in forms to be reconstituted by the addition of boiling water.
Although the first US patent for dehydrating mashed potatoes was granted to Edwards in Eskew, , it was in wartime in industrialized countries in the 20th century that dehydration was widely practiced. Dehydrated potatoes provided combatant troops with a food that was less bulky than fresh potatoes and easier Potato Origin and Production 19 to store and prepare as food.
The reader is referred to Burton for accounts of traditional Andean Papa seca, potato strips and dice, riced potato, potato powder or granules e. Today the major processed products are potato chips crisps and French fries chips and other frozen products, followed by dehydrated products, chilled-peeled potatoes and canned potatoes. Potato processors require potato varieties with specific characteristics to meet demand for quality products, and hence are drivers of modern potato breeding.
Appropriate tuber morphology, adequate solids and low glucose content are important as well as freedom from mechanical damage, bruising and internal defects. Processing usually first involves washing, peeling, slicing or cutting the tubers and defect removal. Then further washing for chips and blanching for French fries and other frozen products, drying, and finally frying which is carried to completion in chip manufacture whereas it is partial par-frying in the manufacture of frozen fries and other products.
The following brief account is taken from the reviews by Burton , Li et al. Potato chips crisps are very thin slices of potatoes 1—1. They are fried in different types of vegetable oil with a range of added flavors. Global manufacturers of chips and other processed products have mostly eliminated the use of trans-fats saturated oils and are launching a range of low-fat and fat composition changes to meet the challenge Kirkman, Potato chips have a US origin dating back to in a hotel kitchen at Saratoga Springs, New York, but commercial production did not get underway until Since the s there have been a number of technical innovations which have contributed to current state-of-theart chip manufacture.
These include the mechanical potato peeler s , packaging in sealed bags s , seasoning technology s , microprocessor-controlled weighing heads , optical sorting to remove defective product and nitrogen-fill to preserve freshness Today the international snacks market is dominated by Frito-Lay which has been part of Pepsico since The company operates approximately 67 plants in 27 countries worldwide. Interestingly, for potato chip manufacture, raw potatoes may be transported long distances whereas finished products have a more limited distribution, reflecting a product with a low weight per unit volume and hence high transport costs.
Frozen fry manufacturers ship their products raw, par-fried, or partially cooked and drizzled with oil for baking, to suit the end user. Heterogeneity in moisture content between strips can result in variability in texture.
The industrial production of French fries came much later in and was then developed during the early s. The invention of the industrial process is generally attributed to Jack Simplot of the J.
Today the global players are McCain, Simplot and Lamb Weston with McCain having 55 plants in 13 countries and markets in countries. French fry factories are usually located close to their raw material sources but the finished products may travel long distances to reach the markets, reflecting their relative weights per unit volume.
Other frozen potato products include waffles, wedges, hashed brown potatoes, rosti, pre-formed mashed potatoes, patties, potato rounds, diced potatoes, baby roasts and a variety of shaped potato products with child-appeal.
Canned potato production constitutes just a small part of the overall market for processed potatoes. Production of chilled-peeled potatoes became established in Europe during — to supply a growing demand by restaurants, takeaways and the catering business. In early 19th century households in potato-growing areas it was Potato Origin and Production 21 commonly prepared for domestic use, before being displaced by factory-starch.
Since then the industry has developed in North America and Europe, particularly in the Netherlands, Poland, France and Germany Burton, , and high dry matter starch varieties have been bred. The main extraction process is wet-milling, including tuber washing, peeling, soaking, disintegration, centrifuging and drying Li et al.
Potato starch has numerous useful functional properties such as thickening, coating, gelling, adhesion, and encapsulation. Today, through effective chemical and physical modifications, potato starch is used in a wide variety of industrial products, including food ingredients, sizing agents for paper and textiles, and starch-based biodegradable plastics Li et al.
Furthermore, high amylopectin starch has been produced by the down-regulation of the granule-bound starch synthase gene that controls amylose synthesis Visser et al. However, commercialization of these genetically modified potatoes is still to take place. Potato starch can also be used for alcohol production. Since the late s, the potato has proved useful for this purpose because of its easy genetic transformation, high productivity, suitability for storage and vegetative propagation.
Potato has been used successfully for developing vaccines or medicines against cholera, other bacteria, cancers, hepatitis B, rabbit hemorrhagic virus, enteric virus, Norwalk virus, foot and mouth disease virus, and diabetes Li et al. Hence the overriding need is for increased and stable yields through new cultivars and better agronomy in the widest sense. Although the potato is a wholesome food, further improvements in its nutritional and health properties are worth considering. Thus there is current interest in improving the health of poor people by breeding staple foods that are rich in micronutrients biofortification , particularly iron, selenium, zinc and beta-carotene vitamin A.
Higher beta-carotene content is now a realistic target for potato given recent success in modifying carotenoid biosynthesis through genetic transformation Ducreux et al. Increased protein content and better amino acid balance has also been achieved through transformation with a non-allergenic seed albumin gene AmA1 from Amaranthus hypochondriacus Chakraborty et al. The issues facing potato production are the need for economic benefits through more yield of saleable product at less cost of production, whether the potatoes are for processing or table use.
Next, there is a need for environmental benefits through a reduced use of pesticides and fungicides and a better use of water and fertilizers, both nitrogen and phosphate. Finally, there is a need to meet consumer demands for convenience foods, nutritional and health benefits, improved flavor and novel products. New cultivars will have an important role to play in achieving these objectives and their production should be greatly helped by the genetic knowledge which is expected from sequencing the potato genome, a task that will be completed by around www.
Targets will be improvements in built-in resistances to pests and diseases, better water and mineral use efficiency, and improved quality and health-promoting attributes. Two examples of the latter are as follows. Varieties with a low GI could be of value in lowering the glycemic load of the Western diet, thus decreasing the risk of type-2 diabetes, cardiovascular disease and obesity Storey, The introduction of inulin to potato is another way to improve its nutritional value because compounds such as inulin reduce the energy density of food and are used to enrich food with dietary fiber or to replace sugar and fat.
Hellwege et al. In summary, understanding the factors that affect the chemical composition of the potato is going to be of increasing importance in ensuring that it continues to make a major contribution to providing humans with adequate supplies of wholesome food. References Almekinders, C. Current status of the TPS technology in the world. Potato Res. Ames, M. DNA from herbarium specimens settles a controversy about origins of the European potato. Balter, M.
Science, , — Bradshaw, J. Potato-Breeding Strategy. In: D. Vreugdenhil Ed. Elsevier, Oxford. Breeding Potato as a Major Staple Crop. In: M. Kang, P. Priyadarshan Eds. Blackwell Publishing, Oxford. Brown, C. Outcrossing rate in cultivated autotetraploid potato. Potato J. Burton, W. The Potato. Chakraborty, S. Increased nutritive value of transgenic potato by expressing a non-allergenic seed albumin gene from Amaranthus hypochondriacus. Chilver, A. Razdan, A. Mattoo Eds. Science Publishers, Inc.
Dale, P. An assessment of morphogenic and transformation efficiencies in a range of varieties of potato Solanum tuberosum L. Euphytica, 85, — Potato Origin and Production 23 Dodds, K. Classification of cultivated potatoes. Correll Ed.
Texas Research Foundation, Renner, Texas. Dodds, K. The history and relationships of cultivated potatoes. In: J. Hutchinson Ed. Cambridge University Press, Cambridge. Drake, F. The World Encompassed. Hakluyt Society, London, 16, Ducreux, L. Engel, F. Exploration of the Chilca Canyon, Peru. Current Anthropology, 11, 55— Eskew, R. Potato Flakes. In: W. Talburt, O. Smith Eds. Foster-Powell, K. International table of glycemic index and glycemic load values: Clinical Nutrition, 76, 5— Gaur, P.
Potato improvement in sub-tropics. In: S. Khurana, G. Shekhawat, B. Singh, S. Pandey Eds. India Potato Association, Shimla, India. Ghislain, M. Genetic analysis of the cultivated potato Solanum tuberosum L. Theor Appl Genet, , — Glendinning, D. Potato introductions and breeding up to the early 20th century.
New Phytol. Golmirzaie, A. Breeding potatoes based on true seed propagation. Bradshaw, G. Mackay Eds. Goodrich, C. The origination and test culture of seedling potatoes.
State Agric. Gopal, J. Food Products Press, New York. Gottschalk, K. Gopal, S. Khurana Eds. Govindakrishan, P. Ecophysiology and Agronomic Management. Hawkes, J. Belhaven Press, London. History of the potato. In: P. Harris Ed. Origins of Cultivated Potatoes and Species Relationships. CAB International, Wallingford.
The potato in Spain during the late 16th century. Economic Botany, 46, 86— The early history of the potato in Europe. Euphytica, 70, 1—7. Hellwege, E. Transgenic potato Solanum tuberosum tubers synthesise the full spectrum of inulin molecules naturally occurring in globe artichoke Cynara scolymus. Henry, C. Glycaemic index values for commercially available potatoes in Great Britain.
British J. Nutrition, 94, — Hijmans, R. Global distribution of the potato crop. Hils, U. World Catalogue of Potato Varieties Agrimedia GmbH, Clenze.
Any switching transition of the power electronic converter connecting the inductive load and the transformer requires commutation of leakage energy. Commutation by passive means results in power loss, decrease in the frequency of operation, distortion in the output voltage waveform, reduction in reliability and power density. In this work a source based partially loss-less commutation of leakage energy has been proposed. This technique also results in partial soft-switching.
A series of converters with novel PWM strategies have been proposed to minimize the frequency of leakage inductance commutation. In this chapter, the current state of using carbon nanotubes CNTs; single- and multi-walled that have attracted great interdisciplinary interest in recent decades due to their peculiar properties for genetic transformation of prokaryotic and eukaryotic cells will be enlightened.
The covalent and non-covalent surface chemistry for the CNT functionalization with focus on the potential applications of surface modifications in design of biocompatible CNTs will be discussed. The properties of CNTs that are favorable for biotechnological use and current status of technical approaches that allow the increase in biocompatibility and lower nanotoxicity of engineered CNTs will be described.
Decisions proposed by non-covalent surface modification of CNTs will be discussed. Existing data concerning mechanisms of CNT cell entry and factors governing toxicity, cellular uptake, intracellular traffic, and biodegradation of CNTs along with bioavailability of molecular cargoes of loaded CNTs will be discussed. Eco-friendly production of water dispersions of biologically functionalized multi-walled and single-walled CNTs for use as nano-vehicles for the DNA delivery in plant genetic transformation of plants will be described.
The background, advantages, and problems of using CNTs in developing of novel methods of genetic transformation, including plant genetic transformation, will be highlighted. Special attention will be paid to the limitations of conventional gene transfer techniques and promising features of CNT-based strategies having improved efficacy, reproducibility, and accuracy along with less time consumption. Issues impeding manipulation of CNTs such as entangled bundle formation, low water solubility, inert properties of pristine CNTs, etc.Moseley, M. Interestingly, hot baked potatoes became popular again on the. The first answer for the question how to develop.
Phylogenetic relationships in the potato and its related species. Potatoes for other uses are stored at intermediate temperatures. Although a much smaller number has been widely grown, this is nevertheless a remarkable achievement for a crop which was unknown outside of Latin America until almost years ago, and which was derived from a narrow genetic base.
The covalent and non-covalent surface chemistry for the CNT functionalization with focus on the potential applications of surface modifications in design of biocompatible CNTs will be discussed.
It had also been introduced into Taiwan and coastal China by European missionaries in the 17th century Pandey and Kaushik, , and likewise into central China by Russian traders also during the 17th century. Even then, the raising of seedlings from seed of self-set berries remained a common practice which continued into the 20th century. Crop Sci. Increased nutritive value of transgenic potato by expressing a non-allergenic seed albumin gene from Amaranthus hypochondriacus.
Planting time is flexible because the farmer does not have to consider the physiological age and condition of seed tubers. First it is necessary to consider how S. Genes from Andean potatoes have also been introgressed into long-day-adapted cultivars and starting in , a number of programs worldwide have selected populations of Andean potatoes to tuber in long days Bradshaw, a, b.
Hence it is likely to have been more widespread when Andean people were using only wild potatoes. These tetraploids were subsequently modified by occasional and unintentional selection of natural hybrids with neighboring wild species to give present-day Group Andigena. Indeed, a striking characteristic of our modern potato is its high harvest index of 0. Origin, evolution, history and spread of potato. Clinical Nutrition, 76, 5—
Resistance to late blight had been introgressed from S.