Differential response of zucchini varieties to low storage temperature

Several parameters related to cold damage in zucchini have been measured in fruits from different varieties cultivated in the province of Almería (south-eastern Spain). The purpose of this work is to correlate physiological parameters with commercial quality and chilling damage, in order to establish reliable criteria for selecting varieties having better genetic adaptation to low-temperature storage. The results show that, for varieties harvested during February, the variety Natura was the best adapted to storage at 4 °C, as its fruits suffered less from chilling injuries, had a lower weight loss, and the levels of metabolites malonyldialdehyde and H₂O₂ were not as high as in the other varieties. Genetic variation was detected for some of the parameters analysed. The positive correlation among the levels of MDA, H₂O_2, and chilling injury, as well as the negative correlation among catalase and chilling injury, makes these parameters good indicators of chilling damage in our system.     

改进的综合气象干旱指数CI_（new）及其适用性分析

针对综合气象干旱指数CI的＂不合理旱情加剧＂问题,采用线性递减权重方法计算近90d降水和可能蒸散,提出改进的综合气象干旱指数CInew,并从干旱过程描述能力、干旱频率及旱期相对少雨季节滞后特征方面,通过与CI相比较阐述CInew的适用性特征。结果表明,（1）CInew在无降水时段平稳下降,有效克服了CI的＂不合理旱情加剧＂问题,能够描述干旱发生、发展和结束过程的丰富细节;（2）CInew的干旱频率与CI相比没有统计意义上的差异,但由于新的相对湿润度指数项MI90new统计时段由原来的30d延长至90d,使CInew能够刻画干旱频发开始月份（11月）相对于少雨时段开始月份（10月）的滞后效应。本文可为CInew在国内其它地方推广应用提供参考。     

基于综合气象干旱指数的干旱状况分析——以锡林河流域为例

降水量与气温是引起干旱的主要气象因子,利用1981—2016年的降水量与气温的逐月数据,绘制最值曲线并对其相关性进行了分析,利用数据计算得到综合气象干旱指数（CI）且用其对锡林河流域干旱状况进行了分析。结果表明:研究区内在1981—2016年中,逐月平均气温最值曲线的变化趋势比较微弱,最高温度与最低温度分别为24.94,-23.53℃。最大降水量的变化趋势呈现出减小的状态,而最小降水量基本无变化,降水量的最大值与最小值分别为178.1,0 mm。36年中,CI指数只有在春季、夏季和秋季3个季节中不为0,在月尺度上只发生轻旱事件共121次,其中春季发生的干旱事件最为频繁;秋季次之;夏季发生干旱事件的频次最少。干旱发生频次呈现出微弱的降低趋势。     

CI指数的改进及其在陕西省的适用性分析

利用陕西4个站点2002—2012年逐日降水、气温资料和气象干旱指数,结合测墒站建站至2012年墒情数据,通过增加变量和调整权重系数对CI进行改进,统计分析改进前后的综合气象干旱指数在陕西干旱过程描述、频率及强度等方面的应用情况和改进效果,并比较了与同期土壤相对湿度的相关性差异。结果表明:改进的综合气象干旱指数(CInew)监测的干旱日数较CI偏少,春夏季尤为明显。各等级干旱发生频率CInew较CI偏低0.1%~8%,年干旱强度较CI平均偏低64.2,但改进前后的综合气象干旱指数在年干旱日数、频率、强度的总体变化特征方面并没有显著差异,均能反映出陕西干旱频率及强度的变化特征。CInew在具体干旱过程监测中的不合理跳跃次数明显减少,克服了CI对弱降水的骤然反应,保留了对强降水的敏感性,CInew与土壤相对湿度的相关性达0.9,较CI明显偏好,监测过程更符合实际干旱的演变规律,程度更贴近实际。因此,CInew可以作为陕西干旱监测与评估指标之一在业务中推广应用。     

土壤阻力连续测试系统农田试验研究

土壤阻力连续测试系统可连续获取农田压实的土壤阻力信息。为研究土壤阻力连续测试系统测试土壤阻力指数(TRI)的适用性,安排了小区对比、大田对比和工作速度影响3个试验,进行了土壤阻力指数TRI值与土壤圆锥指数CI值对比分析。试验结果表明:在表征农田土壤压实程度上,TRI值与CI值具有一致性,即利用土壤阻力连续测量系统测取的TRI数据可以反应农田土壤的压实程度;土壤阻力连续测量系统采样连续、数据信息量大和采样效率高,适合于大面积农田土壤信息快速采集,有利于变耕深耕作技术的开展;在保证系统高效、安全和测试数据稳定的前提下,试验结果显示测试系统较理想的工作速度是1.0m/s。     

植物群落对空气负离子浓度影响的研究

对上海地区常见的21个群落距地面1.5 m的空气正、负离子浓度进行了测试分析,结果表明:群落增加空气负离子浓度极显著高于水泥地,经多重比较发现草坪提高空气负离子浓度的能力最弱,竹类群落提高空气负离子浓度的能力最强;空气质量指数CI值呈正态分布,CI值在0.5～0.7的群落最多;竹类群落的CI最高,均值为0.83,比草坪CI值提高了117%;针叶群落与阔叶群落的CI相近,比草坪CI值提高了70.7%;CI与空气负离子浓度呈极显著正相关,与群落叶面积指数呈显著正相关,与群落优势种的胸径、树高无关;聚类分析结果表明,植物群落可明显改善微环境的空气质量,其中改善空气质量能力较高的群落为群落8、15、16、17等,改善空气质量的能力较差的是草坪、群落12、群落9、群落7.     

宜宾气象干旱对水稻产量的影响分析

本文通过对宜宾综合气象干旱指数CI、不同程度干旱日数,与宜宾市水稻产量做相关分析,研究不同时段干旱对宜宾水稻产量的利弊影响,结果表明,3月出现气象干旱对水稻产量形成有利, 4月、5月、7月出现气象干旱,对水稻产量形成不利,其中,5月分蘖期干旱对产量影响最大。     

Antioxidation responses of maize roots and leaves to partial root-zone irrigation

Antioxidation responses of maize roots and leaves to water deficit and rewatering under partial root-zone irrigation (PRI) were investigated using a pot system. Plants were cultured using three irrigation methods, i.e. conventional irrigation (CI), alternate PRI (APRI) and fixed PRI (FPRI) with three different water regimes including W₁ (70% field capacity, FC), W₂ (50% FC) and W₃ (35% FC). Compared to CI, root peroxidases (POD) activity was enhanced in the irrigated root zone of FPRI and both root zones of APRI during mild water deficit. After rewatering, POD activity was increased in the dry root zone under FPRI but reduced in the roots under APRI. Roots in the dry zone and leaves under FPRI remained high superoxide dismutase (SOD) activity after rewatering. In contrast, SOD activity decreased in the roots and leaves under CI and APRI. Malondialdehyde (MDA) contents were increased in leaves and two sub-roots under FPRI during water deficit and remained higher after rewatering compared to those under CI and APRI. MDA contents in the tissues under APRI showed similar levels to those under CI. Compared to CI, APRI showed the same biomass production, achieving significantly higher water use efficiency under mild water deficit. The results suggested that plants under APRI experienced less oxidative stress or damage induced by water deficit.     

玉米小斑病菌CI小种侵染特征的病理指标比较研究

试验选用１１套同核异质材料，采用田间鉴定与室内鉴定相结合的方法，依据寄主细胞、组织、个体、群体对ＣＩ小种不同反映，分别对ＨＭＣＩ毒素对玉米根冠细胞致死率、针刺病斑长度、幼根生长抑制率、乳熟期病斑长度和面积、接种２０ｄ及乳熟期病情指数７个病理指标进行了比较研究与筛选。结果表明：（１）乳熟期病斑面积可以作为测定寄主对Ｃ中抗性的单一病理指标；（２）确定了综合评价寄主对ＣＩ小种及其毒素综合抗生的３个主万分     

《全宋词》索引研究及其咏农词检索例释

《全宋词》中收录有大量与农业产生和农家生活相关的词,又称咏农词,简称农词。《全宋词》中的农词是研究中国古代农史和文学不可或缺的重要资料,具有重要的文学、文化和史料价值。但是《全宋词》卷帙浩繁,农词散见其中,研究和学习利用时检索极为不便,为了使用的便利,许多人为其编纂了各种索引。文章对已有《全宋词》各索引的类型、功能、编纂方法、编纂技术进行例释、评介,并对《全宋词》索引的发展趋势进行了探讨。