Potato cooking quality directly affects consumers' willingness to purchase potato products. The influence of storage environment on cooking quality is often ignored. In this study, the cooking qualities of ten potato lines stored at 25°C and 4°C for 0, 30, 60 and 90 days were investigated, respectively. The ratio of chlorogenic acid to citric acid content of raw potatoes stored at 25°C remained stable, whereas significantly increased after 60 days of 4°C storage. The lightness of cooked potatoes was significantly decreased after 90 days of 4°C storage, whereas the ACD (after cooking darkening) degree was generally increased at 4°C storage. The hardness of cooked potatoes was generally decreased at 25°C storage, whereas significantly decreased until 60 days of 4°C storage. The sensory evaluation score of cooked potatoes was still higher after 90 days of 4°C storage compared to 25°C. Combined with the genotype-by-storage environment interaction and grey correlation analysis, potato line G1 was screened as an ideal material with excellent and stable performance in cooking quality under different storage conditions. This study established a comprehensive evaluation method to evaluate the impact of genotype-by-storage environment interaction on potato cooking quality, which would help develop strategies for breeding potato cooking processing-type cultivars.

Pollen protoplasts provide a sexual and haploid system for haploid production, cell fusion and mutation studies used in plant improvement. Due to the multiploidy, heterozygosity, and often self-incompatibility in tetraploid genotypes, haploid potatoes are desirable for breeding schemes via ploidy manipulations. In this study, two tetraploid varieties and two dihaploid lines of potato were used for pollen tetrad protoplast isolation and culture. The meiotic tetrad buds were first pre-treated at 5 °C for 0–12 days, then the tetrads were transferred into enzyme solutions containing different concentrations of snailase (0.5–1.5%), 0.3 M osmolites (sucrose, mannitol, glucose or sorbitol), 1.0% Cellulose, 0.5% Hemicellulase, 0.5% Pectolyase, 0.3% Sucrose, 3 mM 2-(N-Morpholino) ethane sulfonic acid, 1% polyvinyl pyrrolidone, 0.01% casein hydrolysate and K3 medium compositions. Among the four donor materials, tetraploid cv. Gannongshu No. 3 (‘GNS No.3’) showed the greatest protoplast yield (74.6 ± 2.4%). In this variety, most of the tetrad protoplasts regenerated a cell wall and continued cell divisions were observed when they were inoculated in K3 basic medium supplemented with (0.5–1.0) mg/L 2,4-D + (0.1–0.5) mg/L KT + 0.4 mg/L 6-BA +800 mg/L glutamine +100 mg/L serine. ‘GNS No.3’ also showed the greatest first division frequency (21.6 ± 1.5%) and sustained division to form multicellular structures. The study findings suggested that cultured tetrad pollen protoplasts could reverse the gametophytic developmental pattern programmed in vivo to a sporophytic pathway leading to multicellular microspore-derived colonies.

[Objective] French fries are the main important potato processing products.The compositions of potato tuber are effected by storage environments after harvest.The change of the tuber compositions affects the features of physio-chemical characteristics of in tubers resulted in potato processing colour and texture.The French fry quality of potato should be analyzed and classified according to the commercially processing criteria.Firstly,screening of French fries processing potato lines according to agronomic traits in fields.Then,analyzing potato tuber processing colour and texture qualities from varieties and advanced lines according to current consumption habits and market demand.The above standards are important required for French fry varieties screening purpose.[Method] Selection at an early breeding stage,characteristics with agronomic traits such as yield,tuber size,tuber shape,tuber colour,eye depth,tuber length,tuber width,ratio of tuber length to width,diseases resistance and commodity rate were evaluated based on three different locations in three years.Fourteen potato varieties and lines were selected for French fry qualities test after storage for 0,60,and 120 days at 4 ℃ and 25 ℃,respectively.The contents of dry matter,starch,total glycoalkaloid,sucrose,reducing sugars,free amino acids,chlorogenic acid,ascorbic acid,citric acid were measured.In addition,the French fry colour change,the tuber and French fry hardness were determined and analyzed.A correlation analysis was conducted to determine the correlation coefficient between the content of starch and the hardness.[Result] In regard to tuber shape,the processing standard for French fry is long to long-oval.A longaxis to transverse-axis ratio greater than 1.5∶1 is acceptable.The ratios refer to variety characteristics as a mean value,not to natural variations in shape which may occur within a variety.Tubers should be uniform and not excessively disfigured by secondary growth,enfolded ends or growth cracks.The values of ΔE reflected the change of French fry colour under different storage environments.The correlation analysis indicated that the changes of colour were caused mainly by fructose,glucose,and secondly by chlorogenic acid.The content of ascorbic acid was correlated only with brightness colour parameter,L value.The content of fructose,glucose,sucrose,chlorogenic acid had a positive significant correlation with a and b values.There was a positive correlation between hardness and tuber starch content in fresh tuber and French fry.The decrease of hardness was caused mainly by the water loss and starch degradation.[Conclusion] The present results indicated that after field agronomic traits screening,colour and texture evaluation under different storage environments,the varieties Russet Burbank,Shepody and lines 0719-32,0716-39 are the better French fry processing potato varieties and lines.

[目的]蒸煮是马铃薯食用最主要的加工方式,马铃薯商业化加工过程中需要对蒸煮加工的品质性状进行定量化分析和分类.根据商业化加工的需求在品种选育中进行蒸煮品质性状的早期选择和筛选,确定蒸煮加工型品种的品质性状特征和相关参数,同时从现有品种和品系中根据商业化加工参数筛选适合不同用途需求的蒸煮品种,是提高蒸煮加工型品种选育效率和方法的有效手段,为制定蒸煮加工型品种选育目标提供基础.[方法]在对马铃薯品种和品系的块茎产量、块茎大小、薯型、薯肉颜色、芽眼深度、抗病性和商品率的初步选择基础上,筛选14个品种和品系进行蒸煮试验,在普通蒸锅中放入块茎蒸煮25 min,蒸熟后,在室温环境冷却20 min,7d后,分别对蒸煮前后块茎色泽变化、蒸煮前后块茎硬度、蒸煮前后软化度进行测定.同时测定这些品种和品系的干物质含量、淀粉含量、蔗糖含量、葡萄糖含量、果糖含量、游离氨基酸含量、绿原酸含量、柠檬酸含量、抗坏血酸含量,分析以上成分在蒸煮加工过程中变化对品种和品系块茎的风味、色泽和质构特性的影响,确定蒸煮加工型品种的加工参数.[结果]选育蒸煮加工型马铃薯品种,首先考虑田间综合农艺性状要能够满足商业化生产与加工过程工艺流程和加工机械要求.块茎还原糖含量是影响蒸煮风味中甜度的主要因素,含量应控制在0.4％以下.游离氨基酸含量与蒸煮风味中鲜味有关,14个品种和品系的氨基酸含量差别还不能构成显著的风味差别,所有品种和品系的氨基酸含量介于30-70 μmol.块茎品种风味构成中的苦味来源主要是糖苷碱含量,蒸煮加工型品种的糖苷碱含量应控制在150 mg·kg-1以下.蒸煮后冷却20 min块茎色泽变化值和蒸煮后7d的色泽变化值△E差值是衡量蒸煮加工型品种色泽变化的重要参数.块茎蒸煮前后的软化度是衡量蒸煮加工型品种质地变化的重要参数.[结论]14个品种和品系块茎蒸煮后的风味、色泽变化、质构特性变化是判定蒸煮加工型品种的重要参数,通过对这些参数的全面分析表明,品种Burbank、Shepody和品系0724-58、0712-66是蒸煮后软化度比较高的品种和品系,而0744-8和0722-26是蒸煮后软化度比较低的品系.

Soil compaction lead to high soil bulk density negatively influences root and tuber of potato.In order to illustrate the effect and adaptation mechanisms of root tissue,stolon tissue,yield and quality of potato under different soil compaction,using potato varieties Shepody,Longshu No.8 and Qingshu No.9 as material,0.79 MPa (T1),0.98 MPa (T2) and 1.24 MPa (T3),on the root and stolon morphology,tuber yield and quality of potato seedlings were investigated using sand columns.The results showed that:(1) With increasing soil compaction,the root and shoot dry weight,root surface area and total root length decreased,while average root diameter and the ratio of root to shoot increased.(2) The increased soil compaction led to the increase of average stolon diameter and the decrease of stolon length.Comparing with control (T1),all the stolons length and diameter of three varieties reached significant difference at P＜0.05 level.(3) Comparing with control (T1),no significant difference (P＜0.05) was found in the tuber yield of three varieties under T2,whereas the significant difference (P＜0.05) appeared under T3.The commodity rate of three varieties was significantly lower than control (T1) with the increasing soil compaction.(4) The dry matter and starch content were increased,the crude protein and reducing sugar content were decreased,and the vitamin C content had no significantly change with the increasing soil compaction.In this study,the response of Shepody,Longshu No.8 and Qingshu No.9 to soil compaction stress were indicated that high soil compaction was a negative impact on the growth and development of root,stolon and tuber,and also affect tuber quality.

[目的]对两个不同生态区域种植的马铃薯品种和品系在低温贮藏不同时间后,通过对加工品质主要成分差异的分析,筛选适应性广的炸片炸条加工品系.[方法]对两个不同生态条件下种植的1个马铃薯品种和4个品系低温储藏后块茎中还原糖、蔗糖、游离氨基酸、绿原酸、抗坏血酸和柠檬酸含量进行测定并比较分析.[结果]还原糖含量,绿原酸含量在两个生态区表现出相同的变化趋势,是评价加工品质的关键指标.游离氨基酸含量、蔗糖含量、柠檬酸含量、抗坏血酸含量可以作为间接指标.[结论]这些指标同时可以作为筛选适应不同生态类型区加工型品种的品质标准;应用以上指标对4个马铃薯品系进行分析,筛选出炸片炸条加工新品系‘08116-39’.

To investigate how calcium relieves cadmium toxicity in maize,the effects of exogenous Ca2 + on growth properties,photosynthetic characteristics and chlorophyll fluorescence parameters of maize seedlings under cadmium stress were studied in a pot experiment.A treatment with 100 mg/L of cadmium obviously in-hibited the growth of maize seedlings,decreased the biomass of plants,and decreased the contents of chloro-phyll a,b and a+b of leaves.At the same time,the net photosynthetic rate (P n ),stomatal conductance (G s ), transpiration rate (T r ),the maximal PSⅡ efficiency (F v/F m ),photosynthetic electron transfer rate (ETR), the efficiency of excitation energy capture by open PSⅡ centers (F v′/F m′),photochemical quenching coeffi-cient (qP ),and the actual PS Ⅱ efficiency (ΦPSⅡ )were reduced whereas the intercellular CO2 concentration(C i )and non-photochemical fluorescence quenching coefficient (NPQ)were increased under cadmium stress.Supply of exogenous Ca2 + under cadmium stress promoted the growth of seedlings,increased the biomass ofplants and raised the contents of chlorophyll a,b and a+b of leaves.At the same time,P n ,G s ,T r ,F v/F m ,ETR,F v′/F m′,qP andΦPSⅡ of leaves tended to be increased with increased exogenous Ca2 + concentration,but C i and NPQ were reduced.Among different Ca2 + application rates,7 .5 to 1 0.0 mmol/L Ca2 + had the greatestalleviation of Cd toxicity effects.It is suggested that Cd stress led to a decrease in the photochemical efficiencyof PSⅡ,reduction in electron transfer,and reduction in net photosynthetic rate.Exogenous Ca2 + at appropriatecon centrations had favorable effects on seedling growth,including enhanced performance of the photosyntheticapparatus and capture of solar energy,effectively ameliorate Cd-induced depression of photosynthesis and enhancingthe resistance of maize seedlings to Cd stress.