5个枇杷晚熟品种果实氨基酸组成和含量分析

为了探讨白肉枇杷和红肉枇杷果实的风味和营养品质的差异,利用氨基酸自动分析仪测定了5个晚熟枇杷品种果实的氨基酸含量。结果表明,新白1号枇杷果实中天门冬氨酸和谷氨酸等鲜味类氨基酸含量占总氨基酸的53.9%,明显高于红肉枇杷中的含量;而红肉枇杷的甜味类氨基酸和芳香类氨基酸含量略高于白肉枇杷。白肉枇杷中药用氨基酸含量高于红肉枇杷,而红肉枇杷符合氨基酸模式谱的指标多于白肉枇杷。     

Evaluation of some systems for classifying soil sensitivity to acid deposition in the South African highveld

Abstract. The Skokloster and Stockholm Environmental Institute (SEI) approaches were applied to the assessment of 145 soils of the South African highveld region in terms of sensitivity to acid deposition. The critical load class calculated by variants of these methods was compared with the acid neutralizing capacity (ANC) determined by pH measurement of soil suspended in a dilute acetate buffer solution. This rapid index of ANC correlates well both with ANC determined by an established but more laborious method which involves titration and equilibration of soil with HCl, and with a number of soil properties related to base status. The correlation between Skokloster or SEI critical load classes and ANC was weak. It was concluded that ANC determination would be a preferable basis for classifying these soils in terms of their sensitivity to acid deposition, since the method is direct and integrates the contribution of various soil properties to acid sensitivity instead of requiring the relative contribution to be calculated according to somewhat arbitrary weightings given to broadly defined classes of soil properties.     

Evaluation and application of DRAINMOD in an Australian sugarcane field

DRAINMOD is a water management model developed to simulate the performance of drainage and water table control systems for shallow water table soils, and it has been widely used in the United States over the last 20 years. This model has been evaluated and applied for predicting water table fluctuations in a sugarcane field for acid drainage management in north-eastern New South Wales, Australia. The reliability of the model has been evaluated using 2-year experimental field data from water level recorders installed in a sugarcane field. Good agreement was found between the observed and simulated values with a standard error of about 0.07 m. However, the model is not readily applicable to daily water management in Australian soils since it requires extensive soil and climate data, which are normally not available for most Australian sugarcane areas. In this application, refinements have been attempted in evapotranspiration estimation and in soil input data preparation so that the model requires only easily obtainable input data but still retains acceptable accuracy. With these improvements, the model can be used as a practical tool for investigating drainage management options for different site conditions. This will assist decision-makers in providing appropriate subsurface drainage management policies, such as acid drainage management, in Australian estuarine sugarcane areas.     

类萜生物合成抑制剂概述

本文综述了类萜生物合成抑制剂的主要种类、作用部位、作用机制、除草对象、在植物体内的吸收与传导以及混用与增效等,提出了类萜生物合成抑制剂进一步研究的方向。     

稀土抗坏血酸络合物的各级稳定常数的测定

本文用ｐＨ滴定法测定了Ｌａ３＋、Ｎｄ３＋、Ｅｕ３＋、Ｇｄ３＋、Ｄｙ３＋、Ｈｏ３＋、Ｔｍ３＋一抗坏血酸络合物的各级稳定常数。同时讨论了生物学效应。     

有机,无机改良剂对酸性硫酸盐土化学动力学与水稻生长的影响

研究了稻秆、碳酸钙和二氧化锰改良剂对淹水的酸性硫酸盐土的电化学、化学动力学、水稻生长及产量的影响. 施用稻秆(干土重的0.25％)显著影响土壤的还原作用.高浓度的亚铁使水稻前期生长受阻;但亚铁的浓度随后逐渐降低,水稻生长繁茂,谷粒和茎秆产量反较高,植株的含钾量也增高. 加入酸酸钙(相当于干土重的0.25％)明显提高了土壤的pH值,降低土壤的Eh和EC值,并显著降低了水溶性亚铁、亚锰和铝的浓度.碳酸钙或碳酸钙加二氧化锰的处理,都能降低土壤溶液中亚铁的浓度,显著增加稻谷和稻杆的产量,此外,这两种处理都会降低生长前期植株中锌的含量. 加入二氧化锰(干土重的0.005％),使土壤溶液中的亚锰量增多,植株的铁锰比率降低,水稻产量比对照显著增加. 研究结果表明,稻杆是一种改良酸性硫酸盐土较经济的改良剂,其价值值得进一步研究.     

1株抗鸡白痢沙门氏菌的乳酸菌鉴定

通过对菌体形态特征、菌落特征和生理生化特性的分析,最终将1株抗鸡白痢沙门氏菌的乳酸菌归类为乳酸乳球乳酸亚种(Lac-tococcus.lactissubsp.Lactis)。     

反义AcInv基因转化马铃薯方法的研究

马铃薯反义AcInv基因,采用农杆菌介导法,选用生产上推广的9个普通四倍体栽培种,对影响转化的各个因素进行了优化研究。结果表明:在愈伤组织诱导过程中,卡那霉素(Km)的适宜浓度为100 mg/L;生根过程中为50 mg/L。外植体的预培养为:茎段2 d,叶盘3 d效果较好;农杆菌浓度当OD600值为0.5时对茎段和叶盘的转化效果均较佳;茎段和叶盘侵染时间分别达8 min和10 min时转化率较高;外植体与农杆菌共培养时间分别为2 d和3 d时,茎段和叶盘的转化率较高;各个品种的外植体在卡那霉素抗性培养基上均能形成愈伤组织,但只有1号(“大西洋”)最后从愈伤组织上分化成苗,形成正常植株,植株再生率为11.2 %,PCR扩增检测表明大部分转基因植株为阳性。     

不同小麦品种籽粒氨基酸组成及其营养品质评价

对１７个蛋白质含量不同的小麦品种籽粒氨基酸分析表明，小麦籽粒氨基酸含量（以种子干重为基础）是籽粒蛋白质含量的函数，不同种类氨基酸与籽粒蛋白的回归关系不同，小麦籽粒氨基酸以及谷氨酸，脯氨酸含量最高，亮氨酸和天冬氨酸次之，必需氨基酸中的赖氨酸和含硫氨基酸（蛋氨酸和胱氨酸）含量最低，小麦籽粒蛋白质的化学评分值为５０％左右，高蛋白品种以赖氨酸为第一限制性氨基酸，低蛋白品种以含硫氨基酸为第一限制性氨基酸。