American Journal of Potato Research最新文献

Solanum jamesii (jam) is the only wild potato species with its natural range primarily within the USA. Its tubers are known to have unusual abilities to survive various environmental stresses. It has been observed during germplasm collecting that mother tubers (those that produced the plant) often appear to be as firm and viable as the new daughter tubers. This prompted investigation of whether such mother tubers can produce multiple seasons of shoots (after periods of intervening cool storage to simulate winter). We compared serial production of 20 cm shoots by the same tuber in subsequent seasons of a set of 162 jam populations to that of a diverse set of 75 populations of 25 other potato species in greenhouse cultivation at the US Potato Genebank. It was rare for tubers of any species other than jam to produce even two serial shoots. But over half of jam populations were able to produce four serial shoots (M4), and 14 populations produced five serial shoots (M5) with tubers remaining firm. When we looked for associated traits, M4 and M5 populations have no apparent single geographic origin or similarity by DNA markers. But natural origin sites for M4 and M5 populations were significantly associated with ancient human habitation. This work reports a new survival mechanism in potato by which a tuber does not expend all resources in maximizing new shoot growth, but instead presumably restocks itself to survive several seasons if all other reproductive options fail. Future work could study the physiological and genetic basis of the trait, and ways it could have practical benefit to the crop.

Potato yield and quality productivity are often constrained by drought stress, which affects food security and sustainability. However, under natural growth conditions, few studies have investigated the response of potato genotypes under field conditions. This study was conducted to assess the response of 29 potato genotypes to drought stress under field conditions. The experiment was set up in a randomized complete block with four replications for two potato-growing seasons using drip irrigation. Drought treatment was initiated 35 days after sowing. The stress treatment was irrigated at 3-day intervals, while the control treatment was irrigated at 6-day intervals until 15 days before harvesting. All potato genotypes showed differential responses to drought stress, with plant height, leaf temperature, leaf area index, total tuber yield, marketable tuber yield and dry matter content being significantly (p ≤ 0.05) affected. Based on the drought tolerance, drought susceptibility and yield stability indices, genotypes MEÇ04, MEÇ07, MEÇ12, MEÇ13, MEÇ16, MEÇ17, MEÇ19, MEÇ20, MEÇ22, and MEÇ24 showed tolerance to drought stress conditions, while the rest of the potato genotypes were susceptible to drought. An analysis of Pearson correlation and principal component analysis indicated that the first four PCs accounted for 70.77% of the total variation in stand establishment, number of stems per plant, plant height, leaf area index, leaf chlorophyll content, leaf temperature, specific gravity, total tuber yield, and marketable tuber yield. Potato breeding material for drought stress tolerance could be derived from these resilient potato breeding lines for potato breeders for future breeding programs to cope with drought stress problems and ensure food security. This study also provides potato farmers and breeders with the characteristic features of potato genotypes ideal for water stress and water-abundant environments. Research is recommended to examine the correlation between morphophysiological and biochemical traits of potato genotypes under water stress conditions by combining morphophysiological and biochemical traits.

Potato black dot is a foliar and tuber blemish disease that has become an increasingly economic problem in recent years. Black dot is caused by the fungus Colletotrichum coccodes and is characterised by silver/brown lesions on the tuber skin leading to lower aesthetic quality of potatoes destined for the pre-pack market. Given the consumers’ growing demand for washed and pre-packed potatoes, skin blemish diseases (such as black dot and silver scurf), once considered of minor importance, are now serious challenges for the fresh potato industry. The management of C. coccodes is far from satisfactory at either pre- or postharvest stages: firstly, the disease symptoms have not been consistently described on potato plant foliage; and secondly, black dot disease is often confounded with other tuber blemishes during postharvest storage. Good field managing practices in combination with improved postharvest strategies and an accurate detection support tool can be a useful integrated approach to manage potato black dot disease. This review aims to evaluate and critically discuss different novel approaches for better management and detection of potato black dot disease.

RT-PCR was used to test whether DNA from potato psyllid (Bactericera cockerelli (Šulc)) could be detected in generalist predators that had been allowed to feed on psyllids in laboratory feeding trials. The assay used primers that had been developed in Europe to amplify a region of the ITS2 gene in psyllids for use in identifying psyllid specimens intercepted at border inspection stations or discovered in regions currently free of the pest. We conducted feeding trials with arthropod generalist predators in diverse taxonomic groups (Araneae, Acari, and two orders of Insecta). RT-PCR readily detected potato psyllid DNA in predators that had recently fed upon the insect. DNA from a closely related psyllid, Bactericera dorsalis (Crawford), was not detected, suggesting that our approach is unlikely to lead to false positives. RT-PCR was found to be more sensitive than conventional PCR at detecting very dilute quantities of potato psyllid DNA. Predator taxa differed in how long after a feeding event prey DNA could be detected. Signal retention was longer in spiders and a predatory mite (Anystis) than in predatory true bugs (Hemiptera). We believe this new molecular tool will be of value in identifying potentially important sources of psyllid biological control under field conditions.

Bactericera cockerelli is a key pest in potato fields throughout the Americas. Yellow sticky traps are widely used for monitoring B. cockerelli within fields and regions. However, these traps lack specificity, which reduces their effectiveness and longevity. Using a mesh to cover their surface is a simple and efficient alternative to improve this limitation. Nevertheless, mesh traits may influence their effectiveness and there are currently no studies examining this for B. cockerelli. Two outdoor experiments were performed to evaluate the capture of B. cockerelli using twelve mesh colors and three sizes. Unmeshed traps were used as control. Additionally, the cleanliness of the traps (nontarget organisms and debris) was also evaluated. The experiments showed that yellow and medium (2.6 mm² hexagon-shape grooves)/large (4.5 mm² diamond-shape grooves) meshes did not significantly reduce the number of B. cockerelli caught and increased the trap cleanliness. Two additional experiments validated these traits. This study provides new useful insights for monitoring B. cockerelli with yellow traps.

The accumulation of cull potato piles is a concern because they take up space and harbor potato-associated pathogens. Black soldier fly, Hermetia illucens, larvae are an increasingly popular agent for converting organic wastes into ingredients for animal feeds. In this investigation, their ability to process cull potato waste was assessed. Potato tubers were suitable for larval development, but only following their disintegration through thermal or mechanical means. Optimal bioconversion was observed when potato substrate was provided at a rate of 1 g per larva. The presence of ground turkey meat and sawdust was generally beneficial to larval development and biomass accumulation. The presence of potato foliage in diet showed no negative effects on larval development and there was no glycoalkaloid bioaccumulation in larval tissues. Evidence from this investigation suggests that culled potato waste may be recycled using black soldier fly larvae.

The increased use of dicamba and glyphosate-tolerant soybean (Glycine max L.) may result in off-target exposure and damage to nearby seed potato (Solanum tuberosum L.) plants. If daughter tubers from herbicide-exposed mother plants are used for seed the following year, daughter plant growth and production may be influenced by the herbicides carried over in the tubers used as seed. The objective of this study was to determine the effects from 'Atlantic' and 'Dakota Pearl' mother plants that were exposed to glyphosate, dicamba, or the combination of glyphosate and dicamba the previous year at the tuber initiation stage on daughter tubers planted as seed. Daughter plants from mother plants that were sprayed with glyphosate at 197 g ha⁻¹ or the combination of glyphosate at 197 g ha⁻¹ and dicamba at 99 g ha⁻¹ had delayed emergence at eight weeks after planting, shorter plants from five to nine weeks after planting, and lower total yield when compared to the non-treated. Daughter plants from mother plants that were sprayed with glyphosate at 197 g ha⁻¹ had the lowest marketable yield, which was less than all other treatments except when daughter plants were from mother plants that were sprayed with the combination of glyphosate at 197 g ha⁻¹ and dicamba at 99 g ha⁻¹. The two chipping cultivars differed in response for plant emergence at five, six, and seven weeks after planting and for canopy development eight weeks after planting. Results suggested that sublethal exposure of glyphosate and dicamba to chipping seed potatoes (mother plants) at the tuber initiation stage the previous year, can influence the growth and development of daughter plants to affect total and marketable yield.

Svalöf is a yellow-skinned, light yellow-fleshed, high-yielding table potato cultivar for the high latitude of Scandinavia, showing partial resistance to Phytophthora infestans (causing late blight) and same specific gravity as the mealy cultivar King Edward, which is preferred in the fresh market by consumers in Sweden. It was selected as breeding clone SLU 1314015 in the first clonal generation (T₁) at the late-blight prone site of Mosslunda (Skåne, southern Sweden) in October 2015. The cross for obtaining it was made by the Swedish University of Agricultural Sciences in 2013 involving the breeding clone D09 1:2 1701 as female parent and the Dutch cultivar Carolus as male parent. Svalöf show very large, round-oval tubers with shallow eyes and smooth skin. Its tuber yield averaged above 6%, 23%, 25% and 59% of Dutch cultivars Connect, Fontane, Carolus and Bintje, respectively, across multi-site trials in Sweden. Its unstable reducing sugar in the tuber flesh, as determined by multi-site testing, suggests that it will not be suitable for the crisp or chip processing. SLU’s Svensk potatisförädling is seeking registration to be included in the Svenska Sortlistan, which lists cultivars available and is a pre-condition for certification of planting materials in the European Union. The release of Svalöf as new potato cultivar will be the first entirely bred for this crop in Sweden since the mid-1990s.

Verticillium wilt affects potato fields in Manitoba where 80% of the fields are planted to the moderately susceptible cultivar, Russet Burbank. An accurate determination of Verticillium dahliae inoculum in soil is critical for disease management. In this study, we investigated the presence of microsclerotia-producing Verticillium species in potato fields in Manitoba and compared published quantitative real-time PCR assays for V. dahliae, V. tricorpus and V. longisporum against a traditional plating method. Selected real-time PCR assays could differentiate and quantify the major microsclerotia-producing species, V. dahliae, V. tricorpus and V. longisporum. Results showed that the presence of V. tricorpus caused an overestimation of V. dahliae propagule density when using the plating method. As a result, Verticillium wilt severity was negatively related to cfu from traditional plating, while positive with the amounts of V. dahliae genomic DNA in soils.