Freezing Tolerance Affected by Mineral Application during Cold‐Acclimated Conditions in Some Cool Crop Seedlings

Abstract

The effect of mineral nutrient application on freezing tolerance in red cabbage, carrot, and spinach under cold‐acclimated and unacclimated conditions were evaluated in this study. Effects of nutrient‐solution application and cold acclimation on temperature at which 50% of leaves are injured (LT₅₀), values, and ice nucleation activity in all of the plants were found to be statistically significant. Nutrient‐solution applications decreased LT₅₀ values in all of the species under unacclimated and cold‐acclimated conditions. Freezing injuries in cold‐acclimated plants were significantly lower than in unacclimated plants in all of the nutrient application doses. In addition to this, 600–900 mg l^?1 nutrient solutions also gave low plant injury in all conditions. Nutrient‐solution applications increased ice nucleation temperatures of apoplastic proteins, proline, and total chlorophyll contents in all of the plant species under unacclimated and cold‐acclimated conditions. Among the plant species, carrot was the most resistant plant to freezing injury under all nutrient application doses in the tested conditions.     

鱼-鸭-菜生态种养模式的方法与效益

鱼、鸭、菜混养技术是一种效益较高的生态渔业模式。于2010年在浙江省丽水市莲都区城关镇水东村养鸭场进行了鱼、鸭、菜共育试验。结果表明,鱼池为鸭提供了清洁的活动场所,而鸭子排泄的粪便为养鱼提供了充足的肥源,水面的空心菜使水体清洁,提高溶氧,也使池塘美观;试验面积1.06 hm2,试验塘(面积为0.53 hm2)和对照塘(面积为0.53 hm2)净产值分别为61 480元和11 130元,投入产出比分别为1.00:1.46和1.00:1.26,鱼、鸭、菜混养的平均纯收入是单纯养鱼的5.5倍,经济效益显著。     

南方气候区冬菠菜需水量分析

[目的]研究南方气候区冬菠菜需水量。[方法]设计3种灌水下限指标处理,分别为田间持水量的90％（处理1）、80％（处理2）和70％（处理3）,每个处理设置2个重复,研究不同灌水指标下冬菠菜的需水量。分析了冬季菠菜的需水量ET;采用改进的彭曼公式计算参考作物腾发量E％,进而求出作物系数Kc;利用水面蒸发量玩计算需水系数d;并用ISD法对需水量、产量、作物系数、需水系数和叶面积作多重比较分析。[结果]各处理的需水量无显著性差异,降雨对需水量的影响很大;处理1的产量和叶面积显著大于处理2、3,处理2、3之间无显著差异。[结论]为节约菠菜灌溉用水和合理利用水资源提供科学依据。     

Leaf chlorophyll readings as an indicator of nitrogen status and yield of spinach (Spinacia oleracea L.) grown in soils amended with Luecaena leucocephala prunings

A field study was conducted to evaluate the nitrogen status and yield of spinach grown in soils amended with prunings of Leucaena leucocephala, (applied at a rate of 3, 5, 7 or 11 t ha^?1). A ‘no fertilizer’ 0 nitrogen (N) and 150 kg N ha^?1 (recommended) were the control treatments. SPAD readings were recorded for the top six leaves. Nitrogen sufficiency indices were used to indicate the N status of plants. Application of L. leucocephala prunings increased spinach yields (8.98–13.86 t DM ha^?1) relative to the 0N treatment (1.35 t DM ha^?1) and yields increased with increasing rate of pruning application. SPAD readings showed a linear increase with the increase in applied prunings. There was preferential distribution of N to upper leaves. The relationship between shoot N concentration and SPAD readings was linear and strongest for the top three leaves (r² = 0.84–0.92). The results indicate the potential of chlorophyll meter readings in assessing N status of leafy vegetables grown on soils amended with different levels of legume tree prunings.     

蚓粪和益生菌互作对土壤性状、菠菜产量和品质的影响

选取两种益生菌(巨大芽孢杆菌和解淀粉芽孢杆菌)分别与化肥和蚓粪配施,研究了蚓粪和益生菌配施对设施蔬菜地土壤化学性状、酶活性及菠菜产量和品质的影响。结果表明:在等养分条件下与单施化肥相比,蚓粪能够显著提高土壤有效磷含量及p H值,降低速效钾、铵态氮含量及EC值,有利于土壤脲酶、蛋白酶和过氧化氢酶活性的提高,有效改善菠菜品质;与单施蚓粪相比,益生菌与蚓粪配施不仅显著提高土壤硝态氮含量、蔗糖酶活性,还增加了土壤EC值,提高了菠菜可溶性糖、蛋白及维生素C含量,且解淀粉芽孢杆菌配施蚓粪还增加了菠菜产量;而益生菌配施化肥对菠菜产量增加和品质改善效果不及益生菌配施蚓粪效果显著。综合比较两种益生菌和蚓粪配施效果,以蚓粪配施解淀粉芽孢杆菌对土壤性状改善和蔬菜产量、品质提高效果最好。     

二硫苏糖醇对海水胁迫下菠菜活性氧代谢及叶绿素荧光特性的影响

 以耐海水菠菜品种‘荷兰3号’为材料,采用水培方法,研究了二硫苏糖醇（DTT）对海水胁迫及甲基紫精（MV）诱导下菠菜活性氧代谢及叶绿素荧光特性的影响。结果表明,海水胁迫与MV处理一样,诱导菠菜叶片产生氧化胁迫,使超氧阴离子（）产生速率、过氧化氢（H₂O₂）含量和丙二醛（MDA）含量显著上升,叶绿素a（Chl.a）、叶绿素b（Chl.b）、总叶绿素[Chl.(a + b)]和类胡萝卜素（Car.）含量显著下降,最大光量子产量（F_v/F_m）、实际光量子产量（Yield）、电子传递速率（ETR）和光化学猝灭系数（q_P）显著降低,而非光化学猝灭系数（NPQ/4）显著上升;海水胁迫与MV处理下,由叶柄导入叶黄素循环活性抑制剂DTT,菠菜叶片活性氧（ROS）大量积累,导致光合色素降解加剧,F_v/F_m、Yield、ETR、NPQ、q_P进一步下降。上述结果表明,海水胁迫抑制了菠菜叶片叶黄素循环活性,降低了叶片非辐射能量耗散能力,加重了叶片ROS积累,从而导致光合色素含量降低,PSⅡ活性下降,电子传递速率降低,用于光化学反应的能量部分减少,光合作用受到严重影响,说明海水胁迫下叶黄素循环在保持菠菜叶片光合色素稳定和光合作用正常运转中发挥重要作用。     

菠菜MAP保鲜及低温贮藏研究

研究了不同初始O2/CO2气体比例的MAP及贮藏温度对菠菜品质的影响.菠菜经充气包装在2℃贮藏17d后分别测定其感官和理化指标,然后将筛选出最优的一组MAP8(0210% C0210%)分别在12℃、5℃和2℃进行贮藏研究.结果表明,MAP菠菜在2℃贮藏17 d后,MAP8(O210% CO210%)和MAP7(O210% CO25%)的保鲜效果好;同时表明MAP8在5℃贮藏17 d后菠菜的叶绿素含量和感官分值较大,可见在这个气体条件下,菠菜的最佳贮藏温度为5℃.     

Influence of growing periods on the quality of baby spinach leaves at harvest and during storage as minimally processed produce

The influence of different growing periods on quality and decay of fresh-cut baby spinach leaves during chilling storage was assessed. Three different spinach crops were sown on October, December and January, respectively. On January–March the vegetable leaves were harvested, analysed for nitrate, oxalate, vitamin C and chlorophyll content and, after the minimal processing operations, the leaves were packaged and stored at 5 °C. During storage, respiration rate, microbiological quality, dry matter, chlorophyll content and colour parameters were monitored. The results show that for all harvests, the initial quality of leaves was acceptable, although slight changes may be due to variability in climatic conditions.     

微生物菌剂在蔬菜上的应用效果初探

为验证沈阳国科生物科技有限公司生产的微生物菌剂在蔬菜上应用效果,以芸豆、菠菜为试验作物,采用对比试验的方式,探讨微生物菌剂对蔬菜生物学性状和产量的影响。试验结果表明:与施用等量清水和基质相比,微生物菌剂可使芸豆和菠菜的生物学性状发生改变,分别增产25.6%和22.3%。     

猪粪中铜、锌与等量水溶性盐对两种叶类蔬菜的植物有效性比较

选取潮棕壤、红壤和灌漠土为试验用土,采用盆栽试验研究了猪粪中重金属Cu、Zn对空心菜和小白菜的植物有效性,并与添加等量Cu、Zn水溶性盐的植物有效性进行了比较。结果表明:当猪粪施用量为50 g·kg~(-1)时,空心菜地上部Cu、Zn含量均低于等量水溶性重金属盐的处理。猪粪中Cu、Zn在潮棕壤、红壤和灌漠土上种植的空心菜的植物有效系数分别为48.95%、89.77%、67.81%和22.40%、10.1%、54.24%,在第二季作物小白菜上的植物有效系数较空心菜均有较大幅度的提高,分别为91.38%、135.97%、128.32%和59.06%、15.23%、99.94%。当猪粪施用量为100 g·kg~(-1)时,三种土壤上空心菜和小白菜地上部Cu含量均高于等量水溶性Cu盐处理。猪粪中Cu的植物有效系数均大于100%,而Zn有效性系数除个别处理外,均低于100%。猪粪中Cu、Zn有效性系数总体呈现随施用量增加、施用时间延长而显著升高的趋势。此外,猪粪中Cu、Zn的植物有效系数在三种供试土壤之间亦有明显差异,猪粪中Cu有效系数为红壤灌漠土潮棕壤,Zn有效系数则为潮棕壤灌漠土红壤。综上,施用猪粪增加了空心菜和小白菜地上部Cu、Zn的含量。