Langstreckentransport von Calcium in Stolonen von Kartoffelpflanzen

Long-distance transport of calcium in stolons in potato plants In potato plants grown in water culture the influence of the tuber growth rate and the Ca supply to the tubers as well as the effect of the relative humidity around the stolons and tubers on the ⁴⁵Ca translocation in the stolon was investigated. If the stolon tip or the tuber were supplied with additional exogenous Ca and the relative humidity around the stolon or tuber was very high then ⁴⁵Ca applied to the roots was translocated in a negligible amount into the stolon or tuber. Even when the supply of exogenous Ca to the tubers was low, the tubers exerted no “sink”-effect on the ⁴⁵Ca translocation within the stolon. Under conditions of high relative humidity around the stolon ⁴⁵Ca applied to the stolon surface was nearly exclusively translocated in direction of the shoot. In contrast, under low relative humidity around the stolon or tuber ⁴⁵Ca applied to the stolon surface or to the root system was translocated into the stolon tip and into the tuber. The results indicate that within the stolon Ca is exclusively translocated in the xylem. A “sink”-effect of the tuber on the Ca translocation into the stolon as well as within the stolon was not been observed.     

Stärkegehalte von Kartoffelknollen in Abhängigkeit von Kalium-Ernährung und Knollenentwicklung

Starch content of potato tubers in relation to K nutrition and tuber growth In a pot experiment with potato (cv Saturna) K content in tubers increased from 1.0 to 2.6 % of tuber-DM due to increasing rates of K fertilizer. Simultaneously starch in tuber fresh matter decreased from 21 to 15 %. Highest starch content in tuber dry matter was obtained in that K treatment which gave the highest yield in dry tubers. Measuring starch accumulation during tuber growth revealed that already in the flowering stage differences exist in the starch contents of the tuber dry matter between the lowest and highest K treatments, namely 69 % for K₁ as compared with 64 % for K₅. The rate of starch accumulation between flowering and final harvest, however, was similar in all K treatments. This suggests that K supply affects the storage tissue at an early stage of tuber development probably via different water relations of tubers.     

钙水平对马铃薯试管薯产量、质量和生理病害的影响

利用MS培养液研究了不同浓度氯化钙对马铃薯试管薯的产量、 质量、 薯内钙含量及生理病害的影响。结果表明,MS培养液中不添加钙时,试管薯的结薯数量、 薯重及大薯率大幅度降低,没有＞100 mg 的试管薯,薯表面出现明显的黄褐色粗糙斑块,个别薯块现水浸状腐烂,腐烂率2.21%。薯内干物质、 淀粉、 可溶性糖和蛋白质含量也较正常钙用量下分别降低了36.8%、 41.39%、 10.7%.和.39.43%,丙二醛含量上升。4℃下贮藏6个月,薯皮失水皱缩严重,平均病害率达53.77%;室温下放置3周,发芽率25.53%,芽生长缓慢;MS 培养液中添加不同浓度的氯化钙,茎段结薯数和薯重随钙浓度的增加呈先增加后降低的变化趋势,大薯率和薯皮表面光泽度呈上升趋势,与正常钙水平相比,薯重增加了2.7%~47.86%、 结薯数增加了-11.49%~22.64%、 大薯率14.43%~26.08%。薯内干物质、 淀粉、 可溶性糖和蛋白质含量的变化均随钙浓度的增加呈先上升后下降的趋势,并较正常钙用量下增加了4.43%~8.62%（干物质）、 6.79%~16.49%（淀粉）、 3.89%~6.31%（可溶性糖）和 4.63%~8.29%（蛋白质）。薯内钙含量大幅度上升,平均值为177~267 g/g（最高值为9 mmol/L处理）,薯皮光滑无水浸状腐烂。4℃下贮藏6个月,薯皮正常,生理病害率随薯内钙含量升高呈下降趋势,病害率为1%~8.9%,决定系数R2=0.3812,且试管薯芽的萌发和生长能力正常。确定MS培养液中添加 9 mmol/L CaCl2是新大坪品种试管薯数量和质量的最优处理。     

Genetic manipulation for enhancing calcium content in potato tuber

Increased calcium (Ca) in potatoes may increase the production rate by enhancing tuber quality and storability. Additionally, increased Ca levels in important agricultural crops may help ameliorate the incidence of osteoporosis. However, the capacity to alter Ca levels in potato tubers through genetic manipulations has not been previously addressed. Here we demonstrate that potato tubers expressing the Arabidopsis H+/Ca2+ transporter sCAX1 (N-terminal autoinhibitory domain truncated version of CAtion eXchanger 1) contain up to 3-fold more Ca than wild-type tubers. The increased Ca appears to be distributed throughout the tuber. The sCAX1-expressing potatoes have normally undergone the tuber/plant/tuber cycle for three generations; the trait appeared stable through successive generations. The expression of sCAX1 does not appear to alter potato growth and development. Furthermore, increased Ca levels in sCAX1-expressing tubers do not appear to alter tuber morphology or yield. Given the preponderance of potato consumption worldwide, these transgenic plants may be a means of marginally increasing Ca intake levels in the population. To our knowledge, this study represents the first attempts to use biotechnology to increase the Ca content of potatoes.     

滴施不同铵硝比例氮肥对马铃薯生长的影响

在盆栽试验条件下,以滴灌施肥方式探讨滴施不同铵硝比例氮肥对马铃薯生长、产量和品质的影响。研究结果表明:在本试验条件下,滴施不同铵硝比例氮肥对马铃薯植株生物量的积累差异不显著;滴施铵态氮肥有利于提高马铃薯块茎中N的浓度,而滴施硝态氮肥有利于提高马铃薯块茎中Ca的浓度;滴施不同铵硝比例氮肥处理马铃薯的淀粉含量、干物质含量、灰分含量等均差异不显著,块茎产量也差异不显著,但马铃薯商品薯比例以滴施铵硝比例为50/50氮肥处理的最高,达到92.01%。     

Phosphorus compounds and their solubility in swine manure compost

In the Japanese warm areas, as a result of intensive and repeated potato cropping, common scab, a soil-borne disease has become a serious problem. The soil moisture level has been shown to be an important factor affecting the incidence of common scab. That is, a high level of soil moisture reduces the severity of common scab. However, in this investigation, although during the spring cropping precipitation was abundant, a large number of tubers showing scab lesions were produced. The results indicate that the soil moisture level may not be an important factor affecting the incidence of potato scab in the humid region.

To identify other factors which may affect scab severity, the relation between sugar content in the peel of potato tuber and the incidence of common scab was investigated. Generally, the amount of reducing sugar in the tuber peel increased gradually with the growth of the tubers, then reached a maximum level two weeks after the start of tuber formation, and thereafter declined. The period corresponding to the highest sugar content in peels coincided with the most susceptible period for scab infection. The content of reducing sugar in the peel of susceptible cultivars was higher than that of the resistant cultivars, throughout the tuber growth, and the critical value of the content was 2.0 mg per 100 g fresh peel. These results suggest that the content of reducing sugar in tuber peel may be an important factor affecting the incidence of common scab.     

Phosphorus and silicon effects on growth,yield, and phosphorus forms in potato plants

Silicon (Si) can increase phosphorus (P) use efficiency (PUE) by increasing P availability in the soil and altering P metabolism in the plant, thus resulting in improved yield under low soil P conditions. The objective was to evaluate the effect of P (10, 50, 100, and 200?mg dm^?3) and Si (0, 50, and 200?mg dm^?3) interrelationship on P and Si uptake by plants, forms of P in leaves and tubers, plant growth, and tuber yield of potato plants. Silicon supply increased organic and inorganic P in the leaves. At low soil P rates, Si also increased organic P in the tubers. However, alterations in the P metabolism of potato plants with Si supply did not promote significant changes in dry matter (DM) production and tuber yield. Phosphate fertilization increased growth and yield of plants. Silicon uptake by the plants were also increased by phosphate fertilization with soil Si supply.     

Soil and tuber calcium affecting tuber quality of processing potato (Solanum tuberosum L.) cultivars grown in Hokkaido,Japan

Calcium (Ca) nutrition for potato (Solanum tuberosum L.) is important to increase tuber Ca concentration and improve potato tuber yield and quality. High tuber Ca content among other benefits mitigates incidence of blackspot bruise through maintenance of membrane health and regulation of biochemical reactions that leads to potato tuber discoloration. However, growers avoid application of Ca fertilizer in potato production in the belief that it causes potato common scab in Hokkaido, Japan. This study was conducted in Hokkaido to determine the current status of soil Ca and tuber Ca content levels, and its effect in mitigating incidence of potato bruise. Soil and tuber samples were collected from 90 and 80 fields in Tokachi and Kamikawa districts, respectively, in 2013 and 2014. Soil samples were analyzed for base saturation, Ca saturation, and exchangeable Al. Tuber Ca content and susceptibility of tubers to bruising were also evaluated. This study found that (1) 81% and 76% of soils collected from Tokachi and Kamikawa district, respectively, were deficient in Ca level, (2) tuber Ca content was lower than the reported value (250 mg kg^?1) considered to mitigate incidence of bruise, and (3) incidence of bruise were influenced by both tuber specific gravity and Ca content. There is urgent need to apply Ca fertilizer to attain increased soil Ca levels and improve quality of tubers.     

Einfluß exogener und endogener Faktoren auf den Calciumgehalt von Paprika- und Bohnenfrüchten

Effect of external and internal factors on the calcium content of paprika and bean fruits In water culture experiments with paprika and bean plants the effect of Ca supply, transpiration and growth rate on the Ca content of the fruits has been studied. A 10-fold increase in Ca supply only slightly increased the Ca content. The Ca content of the paprika fruits was increased considerably at high transpiration rates of either the whole shoot or the single fruit. High transpiration also increased the Mg content but had no effect on the K content. In bean high transpiration rates only increased the Ca content in the early stages of fruit development. The ratio of Ca translocation versus water loss by transpiration sharply declined during fruit growth in both species. In paprika the highest ratio (μg Ca/ml) in the fruits corresponded with the ratio in the leaves. In bean fruits, however, this ratio distinctly exceeded that of fully developed leaves. At high transpiration rates of the shoot 20% of the Ca (⁴⁵Ca) injected into the fruit were translocated out of the fruit. At low transpiration rates of the shoot the corresponding value was below 1%. Most of all the growth rate of the fruits affected the Ca content. With increasing growth rate the Ca transport into the fruits was hardly altered which in turn led to a sharp decrease of the Ca content per unit dry weight. The results support the idea of the Ca transport into the fruit via the xylem. This Ca transport — i.e. also the Ca content of the fruit — is regulated and is also to be influenced by direct or indirect alterations of the water transport in the xylem.     

宁夏马铃薯氮、 磷、 钾养分的吸收累积特征

【目的】马铃薯氮、 磷、 钾养分吸收累积特点国内外已有不少报道,但在宁夏地区的生产条件下尚缺乏系统研究,马铃薯配方施肥技术推广中也缺少施肥参数,难以确定合理的施肥量。因此,针对宁夏地区马铃薯种植基地的土壤条件,系统分析马铃薯干物质累积和氮、 磷、 钾养分含量,探明其对氮、 磷、 钾养分吸收累积特点,以期为马铃薯的精准施肥提供科学依据。【方法】采用田间试验和室内测定相结合的方法。于2012年分别在宁夏西吉县、 原州区、 红寺堡和同心县马铃薯种植基地进行肥料田间试验,按照当地推荐的施肥量统一施肥量和施肥方法(农家肥、 70%氮肥、 全部磷、 钾肥基施,30%氮肥在现蕾期追施),在马铃薯不同生育期采集植株样品,测定不同器官干重和氮、 磷、 钾含量,分析不同生育期马铃薯干物质累积量、 氮、 磷、 钾含量及其吸收累积量的变化特点。【结果】1)从不同种植基地来看,红寺堡区马铃薯干物质累积量最高,其次是原州区和西吉县,同心县最低;马铃薯干物质累积量随生育期的推进而增加,符合Logistic曲线,幼苗期、 块茎形成期、 块茎膨大期和淀粉累积期的干物质累积量分别占总累积量的5%、 20%、 40%和35%。2)马铃薯植株氮含量随生育期而降低,其变异系数较大; 磷、 钾含量随生育期呈先增后减的变化态势,但变异系数较小; 氮、 磷含量叶片高于其他器官,钾含量茎秆中较高。3)马铃薯氮、 磷、 钾吸收累积量在红寺堡区最高,原州区和西吉县居中,同心县最低;苗期氮、 磷、 钾的吸收量分别占全生育期总吸收量的11%、 6%、 8%,块茎形成期占28%、 23%、 31%,块茎膨大期占36%、 39%、 41%,淀粉积累期占25%、 31%、 20%;成熟期块茎中氮和磷的累积量分别占各自总累积量的60%以上,钾的累积量占50%。【结论】供试土壤条件下,马铃薯干物质累积量及养分吸收量因种植基地、 生育期和器官不同而异。从不同种植基地来看,红寺堡区马铃薯的干物质及氮、 磷、 钾累积量较高,原州区和西吉县居中,同心县最低;干物质及氮、 磷、 钾累积量随生育期的变化符合Logistic曲线,具有明显的阶段性特点,块茎膨大期累积最多,块茎形成期和淀粉积累期次之;马铃薯根、 茎和叶中吸收累积的氮、 磷、 钾占同期总累积量的比例随生育期而降低,但块茎则相反,氮、 磷、 钾吸收累积量随生育期而增加,成熟期块茎中吸收累积的养分量占全株的一半以上。     

Effects of different nitrogen forms on potato growth and development

The objective of this study was to test if the effects of different nitrogen forms on potato growth depend on the plant growth stage. Plants from different potato cultivars were treated with different forms of nitrogen before tuber initiation and after tuber formation. A nitrification inhibitor was used to prevent the transformation of ammonium (NH₄⁺) to nitrate (NO₃^?). Plant growth, tuber formation, leaf area, leaf chlorophyll content, and tuber yield were assessed. The results obtained over 2 years indicate that plants treated with NO₃-nitrogen (N) before or at tuber initiation produced more tubers per plant than those treated with NH₄-N. However, plants treated with NH₄-N develop tubers earlier. Additionally, after tuber formation, plants treated with NH₄-N had better shoot growth than plants treated with NO₃-N. A larger leaf area with higher leaf chlorophyll content resulted in greater dry matter accumulation and higher tuber yield at harvest for plants treated with NH₄-N.     

氮肥形态对马铃薯氮素积累与分配的影响

采用田间试验的方法,研究了不同氮肥形态对氮素在马铃薯不同器官中的吸收和运转分配及产量的影响。试验结果表明:铵态氮肥对马铃薯地上干物质积累量的增加作用最明显,施氮处理马铃薯块茎干物质积累量比对照增加50.37%～71.38%;马铃薯各器官中含氮量随生育期推进逐渐下降,其中,茎和叶下降幅度较大;马铃薯各器官中氮含量生育前期表现为叶片>地上茎>根,进入块茎形成期以后,则叶片>根>地上茎>块茎。施氮在马铃薯生育前期有利于茎对氮素的吸收和储存,后期又可以促进茎中的氮素向叶片和块茎转移。施氮各处理产量较对照增加19.28%～63.86%,NH4+-N处理对氮的吸收、积累与分配影响最大,且产量最高,达到39 410.2 kg.hm-2。     

Potato growth and nutrient diagnosis as affected by systemic pesticide and physiological growth stage

Abstract

Growth and chemical composition of crop plants may be subject to alteration by systemic compounds employed for pest control. A field study was implemented to examine the effects of aldicarb on growth, chemical composition, and nutrient diagnosis of a potato crop at various growth stages. Aldicarb use resulted in increased dry matter production of leaves, stems, and tubers, and final fresh tuber weight during the second year of the study. Higher tuber yields were likely due to greater photosynthetic capacity because the increase in leaf dry matter production with time was greater in the aldicarb treatment than in control. Leaf nutrition was not influenced by aldicarb; however, leaf nutrient content varied greatly with growth stage. Similar nutrient status evaluations were generated by DRIS, regardless of pesticide treatment or growth stage. DRIS was able to diagnose nutrient limitations as early as tuber initiation     

Critical potassium concentration and potassium/ calcium plus magnesium ratio in potato petioles associated with maximum tuber yields

In order to establish critical potassium (K) concentration levels and K/calcium (Ca) plus magnesium (Mg) [K/Ca+Mg] ratios in potato petioles associated to maximum total tuber yields, an experiment was conducted under Brazilian conditions. Six K levels (0, 60, 120, 240, 480, and 960 kg K₂O/ha as potassium sulphate) were applied in a randomized complete block design experiment with four replications. Baraka potato tubers were seeded, spaced 0.8 x 0.3 m, following the agronomic cultural practices recommended for the crop. After 48 days from plant emergence, plant tissue samples was collected from each plant, the youngest fully expanded leaves (YFEL) and the oldest but not senescent leaves (ONSL). Petioles from these leaves were analysed to their K, Ca, and Mg contents. At harvest, total, high grade, and weight tuber yields were increased to 733, 719, and 660 g/plant for the 353, 335, and 384 kg K₂O/ha levels, respectively. These yields are double the Brazilian potato yield average. Petiole Ca and Mg concentrations were decreased by the K fertilizer treatments, whereas the opposite occurred with the K/Ca+Mg ratio. Potassium concentrations in the petioles from the YFEL and ONSL increased up to 10.44 and 7.13 g K/100 g petiole dry matter at the 672 and 654 kg K₂O/ha levels, respectively. The K petiole gradient concentration was not affected by K fertilization. The K/Ca+Mg ratio for YFEL associated with the maximum total tuber yield was 7.24, while the K concentrations were 8.91 and 6.16 g K/100 g dry matter in petioles for the YFEL and ONSL, respectively.     

马铃薯专用中耕培土犁的应用及增产效果

中耕培土是马铃薯生产的关键耕作技术,影响马铃薯的产量和品质。传统的中耕培土犁培土效果达不到当前生产作业要求,限制了马铃薯产业发展。为解决该问题,该研究根据马铃薯生产现状,应用自主研发马铃薯专用中耕培土犁,并以传统中耕培土犁为对照,开展不同垄距培土犁培土效果对比试验,设置垄距为65、70、80和90 cm,分别在马铃薯苗期及现蕾期进行2次培土,探讨马铃薯专用培土犁的最佳培土模式。研究结果表明:应用马铃薯专用中耕培土犁培土,垄体明显增大,垄体土壤质量高于对照21.7%~33.4%,有利于马铃薯生育期地下干物质的积累,提高马铃薯匍匐茎数;有利于地下薯块的增长,大、中薯块茎产量增加,小薯块茎所占比率有所减少;马铃薯产量两年平均为38 215.0~43 131.2 kg/hm~2,比对照提高1.1%~7.3%,商品薯产量为33 788.9~39 346.7 kg/hm~2,比对照提高4.1%~11.2%,青薯产量为670.7~834.3 kg/hm~2,比对照降低18.7%~28.8%;其中垄距为80 cm培土处理马铃薯产量最高、青薯产量最低,均值分别为43 131.2和670.7 kg/hm~2,为马铃薯专用中耕培犁的最佳培土模式。该研究可为马铃薯生产提供指导。     

内蒙古阴山北麓高产马铃薯的群体特征

为明确内蒙古阴山北麓马铃薯产区高产马铃薯(产量45 000 kg/hm2)的群体特性,指导该地区马铃薯生产,于2012~2013年在滴灌条件下系统地比较了不同产量水平马铃薯的产量构成、叶面积动态、光合势、干物质积累以及群体生长速率。研究结果表明:种植密度保持在6.0×104株/hm2,块茎膨大期叶面积指数保持在3.07~3.81范围,淀粉积累期仍保持在1.50~1.88,则块茎膨大至淀粉积累期的光合势便占总量的91.6%~94.6%,此期马铃薯以199.9~220.6 kg/(hm2·d)的速度积累干物质,为实现大于45 000 kg/hm2的高产提供了有利的保障。另外,在6.0×104株/hm2密度条件下,水分、养分等供应充足,单株结薯数量可达8个/株以上,大中薯率达90%以上。上述马铃薯群体生理学特征及块茎产量构成因子可作为内蒙古阴山北麓地区高产马铃薯综合管理的重要参考指标。     

Nitrates content in table potato tubers under the influence of herbicides and biostimulants

The objective of the study was to determine the effect of herbicides and biostimulants on the potato tuber content of nitrates. The experimental material consisted of tubers harvested in a field experiment which examined the following factors: three medium early potato cultivars (Bartek, Gawin, Honorata) and five methods of herbicide and biostimulant application (Harrier 295 ZC (linuron?+?chlomazon), Sencor 70 WG (metribuzin), growth regulator Kelpak SL (algae extract from Ecklonia maxima ? auxins and gibberellins), growth regulator Asahi SL (sodium para-nitrophenol, sodium ortho-nitrophenol, sodium 5-nitroguaiacol) and a control unit where weeds were mechanically controlled). The tuber content of nitrates was determined in fresh matter with an ion-selective nitrate electrode and silver–silver chloride reference electrode. Herbicides and biostimulants increased the potato tuber content of nitrates compared with control tubers. However, they did not pose a threat to consumer health. Tubers of plants sprayed with the herbicide Sencor 70 WG (metribuzin) and the biostimulant Asahi SL (sodium para-nitrophenol, sodium ortho-nitrophenol, sodium 5-nitroguaiacol) contained the most nitrates whose accumulation was also affected by cultivars and weather conditions in the study years.     

Jerusalem artichoke growth,development, and field storage. II. Carbon and nutrient element allocation and redistribution

Jerusalem artichokes store carbon (C) predominately in the form of inulin, a functional food of increasing interest due to its dietary health benefits for humans and calorie replacement potential in processed foods. To better understand the developmental and agronomic requirements of this crop, the allocation of C and nutrient elements into individual plant parts (stems, leaves, stolons, tubers, ‘seed’ tuber, and roots) was monitored at 2‐week intervals throughout the entire growth cycle of the cultivar ‘Sunchoke’ grown on a Cecil sandy clay loam. Accumulation patterns of C and nutrient elements in individual plant parts were generally in accordance to the pattern of dry matter accumulation, though concentration patterns differed. Overall, nutrient element levels in vegetative structures decreased with the onset of rapid tuber development. Leaves had the highest nutrient levels, except iron (Fe) and sodium (Na). The concentrations of nitrogen (N), phosphorus (P), potassium (K), sulfur (S), and copper (Cu) in tubers were greater than in stems. Total N, P, and K concentrations in the stolons were at lower levels and the total calcium (Ca), Fe, and manganese (Mn) at higher levels compared to the tubers. During rapid tuber growth, the concentration of individual phloem‐mobile nutrient elements (e.g., N, P, and K) in the leaves and stems decreased progressively due in part to reallocation. In contrast, the concentration of less mobile nutrient elements (e.g., Ca and Mn) in the leaves and stems generally increased due to losses of C and other mobile materials. In the tubers, the concentration of C and most nutrient elements remained fairly constant through the final harvest, indicating carbohydrates and nutrient elements were accumulating at the same rate. Knowledge of C and nutrient element allocation/ reallocation in the Jerusalem artichoke is of value for improving fertilization strategies and in identifying critical traits for the selection of new, high yielding cultivars.     

Fertility Response of Potato to Municipal Wastewater and Inorganic Fertilizers

This study evaluated fertilizer contribution of municipal wastewater on potato (Solanum tuberosum L.) cultivation in a split-plot experiment having two factors: water quality with 5 levels and fertilizer with 2 levels. Irrigation by raw wastewater supplied 16, 13, 13, 23, 1.7, and 83% of nitrogen (N), phosphorus (P), potassium (K), sulfur (S), zinc (Zn), and boron (B) requirement of potato, respectively. Wastewater compared to freshwater, improved plant height, vigority, area coverage, leaf area index (LAI), stem per plant, number and weight of tuber per plant, above-ground dry matter (ADM), and tuber yield of potato. Averaged over 3 years, irrigation by 75 and 100% (raw) wastewater with recommended standard fertilizers produced the maximum, but identical, tuber yield. Wastewater raised N, P, and K contents in potato plants and tubers. Irrigation by wastewater could reduce the fertilizer requirement of potato by 10–15%. However, it caused high accumulation of total coliform (TC) and faecal coliform (FC) on potato skin, restricting the use of the produce.     

Effect of location on starch content and tuber texture characteristics in potato breeding lines and cultivars

The texture of boiled potato tubers is one of the most important quality traits. The variation of tuber texture is usually examined in relationship with dry matter or starch content. The objective of the work was to examine variation and stability of texture and starch content in tubers grown in various environments. Both traits were evaluated for the set of potato breeding lines and 10 table potato cultivars. The lines were developed in the program of parental lines carried out in M?ochów Research Center, Poland. The environments were represented by three locations, which differed in cultivation system as well as climatic and soil conditions. The traits were influenced by the effects of genotype, location and their interactions. The effect of location on texture was not explained by the changes in starch content. The calculated stability parameters indicated that unstable expression of both traits was more pronounced and more frequent in breeding lines than in the cultivars. The short period of selection used in the development of the parental lines is not conducive to select potato genotypes with stable expression of quality traits. The starch content was at most moderately related with various characteristics of tuber texture.