growth, yield, economics and crisp quality Potato Res. 50 1 13 Lakshmi, D.V. Padmaja, G. Rao, P.C. 2012 Effect of levels of nitrogen and potassium on soil available nutrient status and yield of potato ( Solanum tuberosum L.) Indian J. Agr. Res. 46 36 41
Simone da Costa Mello, Francis J. Pierce, Rachel Tonhati, Guilherme Silva Almeida, Durval Dourado Neto, and Kiran Pavuluri
T. Khrais and D. Donnelly
Globally, salinization of agricultural soils is an increasing problem. At least 25% of the world's cultivated land area is now salt-affected. Although the potato (Solanum tuberosum L.) is among the most important of crops plants, little is known of the range of salt tolerance among cultivars of S. tuberosum, wild Solanum sp., or their hybrids. The objective of this work was to rank the salinity (NaCl) tolerance of 200 North American and European cultivars, 13 hybrids of S. chacoense, S. tuberosum, and primitive cultivated diploids (S. phureja and/or S. stenotomum) and their progenies, and 14 accessions of S. chacoense from different collection sites. This was done in vitro, using a modified nodal cutting bioassay. The parameters evaluated included shoot and root lengths, and fresh and dry weights. Extreme variation for salinity tolerance was noted among the cultivars, the hybrids, and the wild species.
Y. Zhang and D. Donnelly
The potato (Solanum tuberosum L.) is considered moderately sensitive to salinity stress. Yields can be adversely affected by salinity at EC levels of 2 to 3 dS·m–1. In vitro screening and selection for salinity tolerance may be faster and more reliable than traditional field assessment. A modified nodal cutting bioassay was developed based on that of Morpurgo (1991) and used to rank the salinity tolerance of several potato cultivars, wild Solanum species, and their hybrids. Nodal cuttings were cultured in Murashige and Skoog (1962) basal medium which included NaCl at 0, 40, 80, and 120 mM. After 4 weeks at 25C and 16/8 h day/night period, vegetative growth parameters were assessed. Hybrids derived from S. chacoense outperformed hybrids of other wild species, their wild parents, and S. tuberosum cultivars. `Russet Burbank' and `Kennebec' were more salinity-tolerant than the three other cultivars tested.
Orville M. Lindstrom, David J. Olson, and John V. Carter
Hardened and nonhardened whole plants of three potato species, Solanum tuberosum L., S. acaule Bitt., and S. commersonii Dun., and one interspecific cross, `Alaska Frostless' (S. tuberosum x S. acaule) were placed in a low-temperature chamber capable of maintaining -4 ± 0.5C for 6 or 12 hours. The chamber was designed to control the root temperature independently from the rest of the plant. Cold acclimation did not affect the ability of any of the potatoes tested to undercool (supercool). Solanum tuberosum and `Alaska Frostless' did not undercool for the times and temperatures tested and in all cases were killed. Whole plants of S. acaule and S. commersonii undercooled, in some cases, for up to 12 hours. When plants of S. acaule froze, they were severely injured, although their hardiness levels were reported to be lower than the temperature to which they were exposed in this study. Whenever leaves and stems of S. commersonii were frozen they were not injured. Once the soil was allowed to freeze, all plants, in all cases, were frozen.
Kent E. Cushman and Theodore W. Tibbitts
Chlorosis and necrotic spotting develop on the foliage of particular cultivars of potato (Solanum tuberosum L.) when grown under constant light. `Kennebec', a cultivar severely injured by constant light when propagated from tissue-cultured plantlets, also was injured when plants were propagated from small tuber pieces (≈1 g). However, plants did not develop injury when propagated from large tuber pieces (≈100 g). Plants from large tuber pieces grew more rapidly than plants from small tuber pieces. The role of plant vigor and carbohydrate translocation in controlling injury development is discussed.
Wesseh J. Wollo and Rufus Jones
The impacts of unloaded quantity, disposable personal income, retail price index of fresh potatoes (Solanum tuberosum L.), and seasonal monthly variables on sweetpotato [Ipomoea batatas (L.) Lam.] price in the St. Louis and Chicago terminal markets were estimated using a regression analysis technique. These markets can absorb a modest increase in sweetpotato quantity without a decrease in wholesale price, but a significant increase in quantity would decrease wholesale price. Sweetpotato price is higher during October, November, and December than in September; therefore, producers must give attention to marketing sweetpotatoes during these months. Also, increased shipments of sweetpotatoes to these markets should not be considered in anticipation of an increase in disposable income.
Anna L. Hale, J. Creighton Miller Jr., K. Renganayaki, Alan K. Fritz, J.J. Coombs, L.M. Frank, and D.S. Douches
The objective of this study was to differentiate six intraclonal variants of the potato (Solanum tuberosum L.) cultivar Russet Norkotah. One-hundred-twelve AFLP primer combinations producing 3755 bands and 79 microsatellite primers producing over 400 bands failed to identify any reproducible polymorphisms among the intraclonal variants and `Russet Norkotah'. The inability to detect differences between clones underscores the degree of genetic similarity between them, despite differences in phenotypic expression. This inability could be due to the tetraploid nature of the clones and/or to epigenetic differences not detected by the utilized procedures.
G. Préstamo and P. Manzano
The various isozymes of peroxidase of a range of vegetables and kiwifruit were compared using sodium dodecyl sulfate polyacrylamide gel electrophoresis followed by specific activity staining. Peroxidase isozymes were determined in potato (Solanum tuberosum L.), carrot (Daucus carota L.), tomato (Lycopersicon esculentum Mill.), kiwifruit [Actinidia deliciosa (A. Chev.) C.F. Liang et A.R. Ferguson], cauliflower [Brassica oleracea (Botrytis group)], green beans (Phaseolus vulgaris L.), and horseradish (Armoracia rusticana Gaertn, Mey Scherb.). There was only one isozyme in cauliflower (70 kDa), two in kiwifruit (45-43 kDa), and a range of isozymes (120-36 kDa) in horseradish. Ascorbic acid inhibited peroxidase activity in the extracts.
Kathleen B. Evensen, Joseph M. Russo, and Harriet Braun
Grading criteria are proposed for judging potatoes (Solanum tuberosum) for chip quality and yield. The criteria were derived from a decision-making scheme developed from expert opinions, U.S. Dept. of Agriculture grades, and a statistical evaluation of stored potatoes. The criteria are presented as ranges of acceptable values for a limited set of variables found to be important for chip quality and yield. These variables include bruising, cracks, cuts, fusarium dry rot, lesions, and scab. The proposed criteria, besides being a practical decision-making tool for processors, could serve as a knowledge base for potato expert systems and the development of mechanized sorting equipment.
Dilson A. Bisognin and David S. Douches
An understanding of the genetic relationship within potato germplasm is important to establish a broad genetic base for breeding purposes. The objective of this study was to assess the genetic diversity of potato (Solanum tuberosum subsp. tuberosum Hawkes) germplasm that can be used in the development of cultivars with resistance to late blight caused by Phytophthora infestans (Mont.) de Bary. Thirty-three diploid and 27 tetraploid late blight resistant potato clones were evaluated for their genetic diversity based on 11 isozyme loci and nine microsatellites. A total of 35 allozymes and 42 polymorphic microsatellite fragments was scored for presence or absence. The germplasm was clustered based on the matrix of genetic similarities and the unweighted pair group means analysis of the isozyme and microsatellite data, which were used to construct a dendrogram using NTSYS-pc version 1.7. Twenty-three allozymes and DNA fragments were unique to the wild species. The diploid Solanum species S. berthaultii Hawkes and S. microdontum Bitter formed two distinct phenetic groups. Within S. microdontum, three subgroups were observed. The tetraploid germplasm formed another group, with S. sucrense Hawkes in one subgroup and the cultivated potato and Russian hybrids in another subgroup. Based upon the genetic diversity and the level of late blight resistance, S. microdontum and S. sucrense offer the best choice for strong late blight resistance from genetically diverse sources. This potato germplasm with reported late blight resistance should be introgressed into the potato gene pool to broaden the genetic base to achieve stronger and more durable resistance.