The effect of storage conditions on subsequent field performance of potato seed tubers in Tunisia

Summary Seed tubers of four cultivars were grown under similar conditions and harvested simulataneously. They were stored in traditional dark storage, diffused-light storage, or cold storage, and with combinations of these three methods for 150 or 230 days beginning in the hot, dry summer period. The effect of storage conditions on emergence, stem and tuber number, tuber size distribution and yield is discussed. Results suggest an optimal combination of storage method, cultivar choice, and sprout management practices may be achieved to obviate the need for cold storage in warm climates. Emergence and yield were consistently good for the 150-day storage period when traditional storage was followed by diffused-light storage. The sam technology gave promising results for the 230-day period with cultivars Claustar or Désirée when seed was desprouted prior to planting.     

Sprouting of seed tubers during cold storage and its influence on tuber formation, flowering and the duration of the life cycle in a diploid population of potato

Summary The influence of a short tuber dormancy and the subsequent sprout growth of the seed tubers during storage at 4 °C on the processes related to plant development and tuber formation was investigated in a diploid population with 238 genotypes, its crossing parents and seven tetraploid varieties. Sprout growth during storage at 4 °C was positively correlated to the duration of the dormancy period at 18–22 °C, the low temperature prolonging the dormancy period. Results show that the duration of the dormancy period and the sprouting of seed tubers during storage at low temperature did not have a determinant influence on plant development, tuber formation or the duration of the plant cycle in this large and highly diverse population of potato.     

The effects of volatile oils on in vitro potato sprout growth

Summary The effects of 10 volatile oils and their main compounds on potato sprout growth were investigated in vitro. Sprout growth was inhibited especially by the volatile oils fromOriganum onites, Rosa damascena, Carum carvi, Mentha piperita, Echinophora tuneifolia andCoriandrum sativum. The major compound of volatile oils was carvacrol (78.2%) inO. onites, citronellol (46.7%) inR. damascena, S-(+)-carvone (54.9%) inC. carvi, menthol (44.1%) inM. piperita, α phelladrene (45.9%) inE. tuneifolia and linalool (76.5%) inC. sativum. The results showed that some volatile oils rich in monoterpenic compounds such as carvacrol, citronellol, geraniol, nerol and S-(+)-carvone were able to prevent the growth of sprouts and extend the storage-life of the potato tubers.     

The effect of chloride fertilization on blackspot susceptibility and other quality characteristics and on yield of potato

Summary Trials were carried out in two years on a sandy loam and on a heavy clay soil with two cultivars to examine the potential of chloride fertilization as a tool to reduce blackspot susceptibility of potatoes and to investigate other effects on yield and quality. Blackspot susceptibility was significantly reduced in cv. Marijke, but not in cv. Bintje as a result of increasing doses of applied chloride from 0 to 400 kg ha1. Dry matter concentration, assessed as under-water weight, was reduced by chloride in both cultivars at the two locations. Fry colour of French fries was improved by chloride. Applying 400 kg ha⁻¹ Cl⁻ to both soil types decreased net tuber yield >35 mm of cv. Bintje but not of cv. Marijke. Chloride caused slower emergence, retarded crop development and less stems per plant on the sandy loam soil but not on the heavy clay soil.     

The influence of mechanical impact and storage conditions on subsurface hardening in pre-peeled potatoes (Solanum tuberosum L.)

Summary In investigating the effect of mechanical impact and storage conditions on subsurface hardening in boiled pre-peeled potatoes, potatoes (cv. Sava) were peeled using an industrial peeler, a laboratory knife peeler or a hand knife peeler, packed in polymer bags and stored at 4 to 18 °C for 6 days. Industrially peeled potatoes were significantly harder than potatoes peeled by hand or using a laboratory knife peeler. Potato hardening was not related to pectin methyl esterase activity (EC 3.1.1.11.). However, it was significantly correlated with mechanical impact from the peeler knives and by treatment in a damage barrel. Blunt knives resulted in harder potatoes than when sharp knives were used. An increase in storage temperature from 4 to 18 °C also increased subsurface hardening significantly. Maximum hardness was found below the wounded surface at a depth of 2–8 mm (average 4 mm).     

Treatment of seed potatoes with prochloraz for simultaneous control of silver scurf and black dot on progeny tubers

Summary Potato seed tubers infected withHelminthosporium solani andColletotrichum coccodes were treated with prochloraz (as Omega 450 g a.i. l⁻¹ EC) and/or prochloraz managanese chloride (as Octave 25 g/kg DP), and planted in two separate fields not previously cultivated with potatoes. Dipping seed 28 d prior to planting in 2,4 or 6 g a.i. l⁻¹ Omega, and dusting with 500 or 750 g Octave per 100 kg seed significantly reduced the incidence of silver scurf and black dot on progeny tubers. In one field, the higher concentrations of Omega and Octave gave slightly better control than the lower Omega concentrations. At the second site, postharvest application of 4 g a.i. l⁻¹ Omega or 750 g Octave per 100 kg seed limited development of both diseases on progeny tubers, with slightly better control when an additional Octave dusting was applied 14 d before planting. None of the prochloraz treatments adversely affected plant stand or tuber yield.     

甘蓝型油菜种子贮藏蛋白遗传距离与杂种优势关系研究

对38份不同生态区来源的甘蓝型油菜种质进行了贮藏蛋白电泳多态性分析,并对165个杂交组合农艺、品质性状表现及杂种优势与亲本贮藏蛋白距离进行相关分析,探讨了贮藏蛋白标记遗传距离辅助甘蓝型油菜农艺及品质杂种优势利用的可能性。结果表明：甘蓝型油菜种子贮藏蛋白多态性丰富;谷蛋白标记遗传距离（GDglu）、清蛋白标记遗传距离（GDalu ）与农艺、品质性状杂种后代表现及中亲优势存在不同程度的相关性,可以利这种相关性及谷蛋白标记遗传距离聚类辅助甘蓝型油菜杂交育种和品质育种的亲本选配,提高选配效率。     

The effect of water stress on the yielding capacity of potato crops and subsequent performance of seed tubers

Summary The effect of water stress on yielding capacity of potatoes was studied in 3 years using four different levels of soil water potential (0.7, 1.9, 3.4 and 7.8 atm.) in experiments in specially adapted structures that excluded uncontrolled water supply. Seed tubers from these crops were planted in the following years to investigate effects of water stress on their subsequent performance. Limited soil moisture availability decreased yield and the number and size of tubers. The growing period was shortened by 1–4 weeks and dormancy period by 2–8 weeks. In the following year, seed produced under conditions of moisture stress gave plants with 20% fewer stems. 24–33% less yield, 18–22% fewer tubers and 19–22% fewer large tubers than plants from seed produced under abundant water supply. It is concluded that the yield potential of seed tubers can be improved by careful attention to the availability of soil moisture during their production.     

Performance of potato minitubers in a controlled environment after different storage periods

Summary Minitubers of cultivars Agria and Liseta were harvested from the same plantlets on three dates. After each harvest, tubers were dried (1 day), cured (13 days) and cold stored at 2 °C in darkness and 80 % RH. Their performance was studied 65, 128, 191, 254, 317, 380, 443, 506 and 569 days after harvest. Minitubers (1–2 g) were planted in pots and grown for 8 weeks in a controlled environment. After 191 days of storage their growth was still extremely poor. In both cultivars, tallest plants and largest leaf areas per plant were observed in plants from tubers from the second and third harvests that had been stored for 317 days. Highest stem numbers, yields (total dry matter, tuber fresh weight) and harvest indices were achieved with 443 days storage with cv. Agria and 569 days storage with cv. Liseta. Tubers from the first harvest behaved slightly differently.     

干旱胁迫对不同类型红花品种（系） 苗期生理生化特性的影响

为筛选抗旱品种提供依据,本试验从14份红花品种中筛选出2个抗旱品种（PI401470和PI401477 ）和2个干旱敏感型品种（系）（PI560169和川红1号）,并以此4份品种（系）为材料,研究干旱胁迫对红花幼苗光合、渗透调节物质和抗氧化物保护酶等生理生化特性的影响。结果表明,干旱胁迫下,4个红花品种（系）叶片净光合速率（Pn）、气孔导度（Gs）、胞间CO2浓度（Ci）和蒸腾速率（Tr）均呈不同程度的下降趋势,且品种间差异显著（P﹤0.05）;抗旱红花品（系）的各光合特性指标降幅均低于敏感型红花品种（系）。干旱胁迫条件下,渗透调节物质可溶性糖、可溶性蛋白质、脯氨酸含量均上升,保护性酶SOD、POD和CAT活性也均呈升高趋势,且抗旱型红花品种（系）的增长率高于敏感型品种（系）;抗旱型品种（系）MDA含量增长率低于敏感型品种。对11项指标进行主成分分析,提取了2个主成分,以净光合速率、气孔导度、胞间CO2 浓度、蒸腾速率、SOD活性和CAT活性为第一主成分,以可溶性蛋白质和脯氨酸为第二主成分的抗旱性鉴定指标,累计贡献率达89.50％。     

The effect of irrigation and nitrogen on powdery scab and yield of potatoes

Summary Powdery scab, caused by the fungusSpongospora subterranea, has developed in the Cappodocia region of Turkey because of changes in agronomic practices, such as excessive irrigation and nitrogen fertilizer use and growth of highly susceptible cultivars. The most suitable irrigation and nitrogen application levels were established to maintain powdery scab at minimum levels without affecting potato yield. Three irrigation levels were used in 1998 (673, 897, 1121 mm) and five in 1999 (329, 494, 658, 823, 987 mm). Nitrogen levels were applied 150, 300, 450, 600 kg N ha⁻¹. In 1998, least powdery scab occurred with 673 mm irrigation, which yielded 41 t ha⁻¹ potatoes. The lowest disease severity occurred in 1999 with 494 mm irrigation and 150 kg N ha⁻¹. At these levels, tuber yield was 34 t ha⁻¹ which was not significantly different from the highest yield measured. In 1999 and at two of the three irrigation levels inl998, nitrogen increased disease severity.     

污水灌溉对小麦幼苗生理特性及抗氧化酶活性的影响

用不同浓度的污水分别对小麦幼苗进行处理,测定其根系活力、细胞膜透性、超氧化物歧化酶（SOD）活性、过氧化氢酶(CAT)活性、过氧化物酶(POD)活性及丙二醛（MDA）含量。研究了污水对小麦生理特性及抗氧化酶活性的影响。结果表明：随着污水处理浓度的提高,根系活力不断降低,细胞膜透性不断升高, SOD、CAT及POD活性均表现为先升后降的趋势, MDA的含量呈逐渐上升的趋势。     

干旱胁迫下不同苎麻品种的形态解剖特征研究

抗旱性强的苎麻品种,在正常水分条件下叶面茸毛多、叶着生角度小、比叶重大,而在干旱胁迫下叶片衰老慢,根冠比大、根活跃吸收面积大、萝卜根数量多且直径大,纤维细胞直径和胞壁厚度降低幅度小。抗旱性强的苎麻品种正常水分及干旱条件下叶片气孔密度以及茎导管和根系维管束均较大。     

Influence of different storage conditions on quality characteristics of seed material from semi‐natural grassland

Neither methodology nor guidelines are available for defining quality characteristics and storage conditions of seed material harvested from semi‐natural grassland. Seeds from an Arrhenatherion meadow were harvested via on‐site threshing and seed stripping. After determination of purity, thousand seed weight and pre‐tests in a phytotron, germination‐capacity trials were carried out in a greenhouse. The harvested seed material was stored for up to 3 years under different conditions: (i) room temperature 18–23°C, (ii) cooling chamber (2–5°C with 40–50% humidity) and (iii) freezer (?18°C). There was a significant impact of the tested harvesting methods on seed separation, thousand seed weight and purity, but not on the germination capacity. Different storage conditions and storage length significantly influenced the germination capacity. There were also generally higher germination values for the seed‐stripping material than the on‐site threshing material (ca. 70 and 60%, respectively, in the first year). Germination capacity decreased significantly with time and was <15% after 3 years. We conclude that harvested seed material from semi‐natural grassland should preferably be stored under cool conditions and used within 2 years.     

红毛丹种子贮藏及发芽试验初报

[目的]为红毛丹种子的贮运、播种时间等提供参考,并为提高红毛丹杂交育种的种子成苗率提供科学依据。[方法]以红毛丹为材料,通过不同储藏方式对红毛丹种子进行储藏,以研究不同贮藏方式和贮藏时间对红毛丹种子发芽的影响。[结果]常温贮藏和低温(4℃)贮藏下种子发芽率整体趋势随着贮藏天数增加逐渐降低;低温贮藏的种子发芽势随着贮藏天数的增加逐渐降低,常温下贮藏8 d的种子发芽势最大,为32.5%,常温下贮藏4 d的种子发芽势最低,为10.0%。[结论]常温贮藏下种子发芽率和发芽势整体趋势均高于低温贮藏下的种子。     

Influence of daylength and temperature during formation of seed potatoes on subsequent growth and yields under long day conditions

Production of high quality seed potatoes is normally favoured by a cool climate with minor pest problems. Growth chamber studies aimed to reveal if daylengths (12 and 24 hrs) and temperatures (18/12 and 12/9°C day/night) during production also might influence progeny growth. Results showed no significant carry-over effect from daylength conditions, while growth vigour and yields were affected by parent plant growth temperature. Further experiments, including a greater range of temperatures, different cultivars and measurements of physiological age, are required to discuss theoretical and practical implications of the results.     

Effects of saline irrigation water and heat waves on potato production in an arid environment

Production of spring potato (Solanum tuberosum L. cv. Désirée) on a deep sandy soil in the central highland of the Negev desert of Israel under drip irrigation with saline water (up to 6.2 dS m⁻¹) was studied in the years 1992–1997. The objective of the study was to determine the effects of saline water irrigation on potato production in an arid environment with special focus on the interactions with weather conditions. Although yields were often high, salinity effects were evident in some years. Thus 1992 and 1996 yields were 6–7 kg m⁻² and showed no significant effect of salinity, while a pronounced drop in yield with increasing salinity was observed in 1993 and 1994. Analysis of weather data for 1993–1994 suggests that the decline in yield was due to interactions between saline irrigation and prolonged heat wave events occurring during crop development. Further experimental work (1997) revealed that tuber yield was most sensitive to combined salt and heat stress when heat waves occurred at 40–60 days after emergence. The combined stress apparently leads to the collapse of mechanisms for avoiding salt accumulation in young expanding leaves, resulting in failure of vegetative growth recovery and a consequent reduction in the leaf area index and canopy functioning. The relationship between tuber sink demand and available photoassimilate supply at certain stages of plant development is discussed with reference to the ability of the potato plant to recover from the combined stress.     

三裂叶蟛蜞菊对花生化感作用的生理生化机理

三裂叶蟛蜞菊(WedeliatrilobataL.)是华南地区的重要杂草和园林绿化植物。本文研究了三裂叶蟛蜞菊水提液对花生种子萌发和幼苗生长过程中一些生理过程的影响。结果表明,三裂叶蟛蜞菊各器官水提液浸种显著降低了萌发花生种子过氧化物酶活性和脂肪酶活性,提高了质膜透性,进而使萌发花生种子的活力和呼吸速率显著降低。其中三裂叶蟛蜞菊根、茎、叶和全植株水提液使萌发花生种子过氧化物酶活性分别降低了32.80%、39.48%、32.37%和34.40%,使脂肪酶活性分别降低了21.19%、26.69%、24.15%和22.88%。在花生植株幼苗生长过程中,喷淋三裂叶蟛蜞菊各器官水提液极显著地降低了花生根系干物重、单株根瘤数、叶片叶绿素含量、净光合速率和单株干物重;其中三裂叶蟛蜞菊叶水提液分别使花生叶片叶绿素含量、净光合速率和单株干物重降低31.95%、32.65%和37.93%。喷淋三裂叶蟛蜞菊各器官水提液还极显著地抑制了花生氮素代谢中两种关键酶—硝酸还原酶和谷氨酰胺合成酶的活性,使叶片全氮含量有所下降。三裂叶蟛蜞菊各部分水提液对萌发花生种子化感作用的大小顺序是:茎>叶>全株>根系;而对花生幼苗,化感作用的大小顺序则是:叶>茎>全株>根系。     

The effect of storage conditions on chemical content of raw potatoes and texture of cooked potatoes

Summary Texture of boiled potato tubers (cv. Beate) was studied over several months of storage at either 4 or 8 °C, in relation to dry matter content, non-starch polysaccharides (NSP), methyl groups, glucose, starch and amylose. The dry matter content decreased significantly during storage at 4 °C, but increased at 8 °C due to evaporation. The insoluble NSP contained rhamnose, galactose, arabinose, xylose, mannose, fucose and glucose; the first three sugars decreased significantly after the first 7 weeks of storage. Fracturability and percent compression before break increased during storage at 8 °C, particularly percent compression after 15 weeks. The change in fracturability could partly be explained (R²=43.4%) by the content of the NSP and the increase in percent compression by dry matter (R²=91.8%). Changes in texture during storage at 4 °C, however, were not striking, and could not be explained by changes in the potato components that were analysed.     

盐旱交叉胁迫对花生生长发育和生理特性的影响

为了探究盐旱交叉胁迫对花生生长发育的影响,以抗旱不耐盐花生品种花育22和抗旱耐盐花生品种花育25为试验材料,通过防雨棚盆栽试验研究了干旱、盐、盐+干旱、干旱后复水+盐等4种胁迫对花生产量、农艺性状、生物量、叶绿素SPAD值、丙二醛含量、活性氧清除能力及渗透调节物质含量的影响。结果显示：各胁迫处理均显著抑制了两个花生品种植株的生长和荚果产量,其中,盐胁迫对花育22生长的影响大于干旱胁迫;盐+旱胁迫下,两个花生品种受伤害程度最大,产量最低。与单一盐胁迫相比,干旱预处理提高了盐胁迫后期花生超氧化物歧化酶和抗坏血酸过氧化物酶活性,增强了植株活性氧清除能力,降低了叶片丙二醛含量,从而缓解盐胁迫对膜系统的过氧化伤害,提高了叶绿素含量,促进了植株生长,增加了干物质积累,最终提高盐胁迫下花生产量。另外,与单一盐或干旱胁迫相比,盐+旱胁迫对花育22和花育25的伤害均加重,而干旱预处理有利于2个品种在盐胁迫下活性氧代谢和光合色素的提高,促进植株的生长,提高植株对盐胁迫的交叉适应能力,从而缓解盐胁迫对花生植株的抑制作用。