滴灌条件下枣树耗水规律的研究

试验通过研究枣树的茎流来预测其耗水量,为合理灌溉提供科学依据。利用植物茎流计在滴灌条件下测定枣树的茎流变化,结果表明2010年5月15日的最大值出现在中午12∶00,达到1834．28 g · h－1,6月26日的最大茎流速率在13∶00,达到4861．89 g·h－1,7月20日最大值出现在15∶00,达到6385．88 g·h－1,8月10日最大茎流出现在16∶00,达到5816．86 g · h－1;最小茎流都是出现在凌晨4∶00～8∶00。5月份的日平均累计流量比较小,枣树在这个月的日平均耗水量反而最小,到了7、8月份,随着温度的升高和雨季的结束,枣树耗水量明显增加,8月的日平均耗水累计量最高;通过相关分析,地表最高温度和最高气温对枣树的茎流量影响较大。研究得出：土壤含水量是影响茎流的变化主要因素,其它环境因子对茎流的影响也很重要。     

植物光合作用测定法确定灭草松和特丁津混用的最低致死剂量

在荷兰瓦赫宁根国际植物研究所温室内,用植物光合作用测定法研究了光合作用抑制型除草剂灭草松和特丁津桶混防除6种常见阔叶杂草的最低致死剂量。结果表明,药剂对杂草的生长有明显的抑制作用,在施药2 d后可观察到明显的灭草松的防效,在施药8 d后可观察到明显的特丁津的防效。随着施药剂量的增加,杂草叶片的植物光合作用测定(PPM)值和杂草地上部分鲜重显著下降。供试的6种杂草对该混剂的敏感性存在显著差异:红心藜Chenopodium album、龙葵Solanum nigrum和反枝苋Amaranthus retroflexus对该混剂最敏感,ED90值分别为47.65、71.67和29.17 g/hm2;春蓼Polygonum persicaria和苘麻Abutilon theophrasti敏感,ED90值分别为96.91、114.20 g/hm2;而番茄不敏感。比较施药后2、4和6 d时杂草叶片的PPM值与施药后16 d时杂草地上部分鲜重防效的相关性可以发现,施药后4 d杂草叶片的PPM值与鲜重防效的相关性最好,相应的R2为0.924 7。表明PPM值可以较好地预测防效,在本试验条件下,施药后4 d的PPM值的预测效果最好。     

基于EM38的玛纳斯县土壤剖面盐分的解译模型构建

大地电导率仪(EM38)是快速无损测定土壤盐分的有效方法。为建立新疆农田土壤EM38测试值与土壤盐分关系模型，以新疆玛纳斯县农田土壤为研究对象，利用EM38在野外实地测定土壤表观电导率，并挖掘土壤剖面进行分层采样，室内测定土壤盐分含量，据此构建基于EM38的土壤盐分解译模型。结果表明：（1）利用土壤实测盐分和EM38电导率数据，分别建立不同土壤深度下EM38垂直模式和水平模式以及两者联用的二元线性回归土壤盐分解译模型。（2）3种EM38盐分解译模型的R2随着土壤深度增加而增加，并且在土壤深度小于20 cm时，垂直模式的解译精度大于水平模式，深度大于20 cm后，解译精度则刚好与之相反。（3）二元线性回归模型的解译精度明显优于一元线性回归模型。本研究所构建的EM38土壤盐分解译模型，将为绿洲农田土壤盐分快速调查和动态监测提供可靠的反演参数和模型。     

Comparison of a portable blood glucose meter analyzer with a benchtop point-of-care chemistry analyzer for measurement of blood glucose concentration in client-owned ferrets (Mustela putorius furo)

BackgroundHypoglycemia is common in pet ferrets (Mustela putorius furo) because of the high prevalence of insulinoma in this species. The objectives of this study were to evaluate agreement of a portable blood glucose meter (PBGM) with a benchtop point-of-care (POC) chemistry analyzer for measurement of blood glucose concentration in ferrets, and to assess the clinical impact of using a PBGM for blood glucose measurement. The benchtop POC analyzer was used as the reference analyzer (modified hexokinase method).MethodsGlucose concentration was measured from 82 blood samples from client-owned ferrets with the benchtop POC chemistry analyzer and the PBGM. Agreement and bias between measurements were assessed using the Bland-Altman method and a Passing-Bablok regression analysis. A modified Clarke error grid analysis was modelized to evaluate the clinical effect if the PBGM was used rather than the benchtop POC chemistry analyzer.ResultsGlucose values obtained with the PBGM were not in agreement with the benchtop POC chemistry analyzer, and it underestimated blood glucose concentration in many cases. However, variation was unpredictable (mean bias, -3.97 mg/dL; range, -52.2 to 64.8 mg/dL), with wide 95% LOA (-47.3 to 38.5 mg/dL). A Passing-Bablok linear regression analysis had a slope of 1.13 (95% confidence interval: 1.00–1.36), and an intercept of -20.78 (95% confidence interval: -38.92 to -9.90), highlighting presence of a proportional and a constant bias. Important clinical error would have occurred in 1% of cases with the PBGM.ConclusionUnpredictable variation of glucose results obtained with the PBGM could have an important impact on clinical decision making. Thus, the use of a benchtop POC analyzer using hexokinase method for measurement of blood glucose concentration should be favored in ferrets for rapid onsite result obtention.     

陕A群和陕B群选育玉米自交系的子粒脱水特性研究

以陕A群、陕B群选育11份不同熟期玉米自交系为材料，通过播期调整使所有材料同天授粉，同时利用烘箱法和电子水分测量仪法测定不同时期玉米子粒含水率，分析子粒水分动态变化规律和子粒脱水特性。通过比较分析两种方法，发现授粉35DAP后两种方法测定的子粒水分含量显著相关(P<0.05)，此阶段电子水分测量仪法可替代烘箱法。聚类分析显示，可将11个试验材料划分为5种脱水类型，KB182和KA225为早熟脱水快型；KB207属于早熟脱水慢型；中熟材料KB089、KA147和XCA-1属于渐进脱水型；KA105属于晚熟脱水快型，KA327、2082和KB020属于晚熟脱水慢型。中熟材料KB089和晚熟材料KA105在同一熟期材料中达到最大灌浆速率所需时间较短，具有较快的灌浆速率且生理成熟期后脱水速率快的特点，可作为高产宜机收品种选育的优异种质应用于育种实践。     

Relationship of IAD index to internal quality attributes of apples treated with 1-methylcyclopropene and stored in air or controlled atmospheres

The research was conducted to evaluate the relationship between I_AD index (index of absorption difference between 670 and 720 nm) values and internal quality attributes of apples treated with 1-methylcyclopropene (1-MCP) and stored in air and controlled atmospheres (CA). Apples of ‘8S6923’ (Aurora Golden Gala™), ‘Fuji’ and ‘Royal Gala’ were tested. The results with Aurora Golden Gala™ show that I_AD index values were maintained at higher levels if the fruit were stored in CA and that 1-MCP had no significant effect on retaining at-harvest values. The I_AD values correlated with chlorophyll a content in the peel (R² = 0.95, P < 0.0001), but not with chlorophyll b content, internal ethylene levels, firmness or titratable acidity. ‘Royal Gala’ apples showed a similar response to Aurora Golden Gala™ apples, showing no correlation between I_AD index values and internal quality attributes of those apples when treated with 1-MCP and/or CA. In contrast, ‘Fuji’ apples showed a relationship between I_AD index value changes and internal ethylene concentrations (R² = 0.67, P < 0.05) and titratable acidity changes (R² = 0.89, P < 0.01), but not firmness. These results suggest that when 1-MCP and/or CA are applied to apples after harvest, that I_AD index values do not consistently correlate to any internal quality attributes other than peel chlorophyll a content.     

长沙丘陵区油茶林地土壤蒸发的时空变化

2019年4—9月,采用微型蒸渗仪测定长沙丘陵区油茶林地土壤蒸发量;利用ETgage模拟蒸散仪监测林地局部蒸散量,对比分析长沙丘陵地区土壤蒸发量的时空变化,探讨土壤蒸发随气象因素和土壤含水量的变化关系.结果 表明:长沙丘陵区油茶林土壤蒸发总量约为192.15 mm,日均为1.05 mm;不同空间位置上,阳面、绝对阴面、...