Behavioral and physiological responses of cabbage looper,Trichoplusia ni (Hübner), to steam distillates from resistant versus susceptible soybean plants

Soybean plant volatiles, extracted as steam distillates, significantly affected the behavior and biology of the cabbage looper,Trichoplusia ni (Hübner) (Lepidoptera: Noctuidae). Distillates from the susceptible Davis variety attractedT. ni larvae and female adults, whereas those from resistant PI 227687 plants repelled them. When mixed in an artificial diet, steam distillates from PI 227687 plants caused mortality of first-instar larvae. Adults emerging from pupae topically treated with 5 g of such PI 227687 extractable showed developmental abnormalities. Larval feeding was significantly less on Davis leaves treated with PI 227687 volatiles as compared to solvent (acetone) or such Davis extractables. However, Davis volatiles on PI 227687 leaves did not increase larval feeding. HPLC analyses of steam distillates from susceptible Davis versus resistant PI 227687 indicated differences.     

The Improvement of the Quality of Raffinate Obtained from Solvent Extraction of Lubricating Oils

Abstract

Vacuum distillates of an Egyptian crude oil were subjected to solvent extraction process applying N-methyl-2-pyrrolidone (NMP) and furfural as dearomatization solvents. The study shows that the extraction solvent together with the temperature and solvent-to-oil ratio have a significant effect on the yield and quality of produced lubricating oils. The optimum temperature for extracting light waxy distillates with NMP is 55°C at the solvent-to-feed ratio 2:1. These conditions are appropriate to remove the major portion of aromatics from the raffinate. The apparent activation energy (Ea), enthalpy (ΔH*), entropy (ΔS*), and free energy of activation (ΔG*) were calculated for the solvent dearomatization process.     

基于电子鼻和GC-MS评价不同品种葡萄采后品质和挥发性物质的变化

为明确不同品种葡萄果实采后品质和挥发性物质的差异,本文通过顶空固相微萃取及气相-质谱联用技术(HS-SPME-GC-MS)测定4个不同品种葡萄新鲜果实挥发性物质成分和相对含量,并以电子鼻辅助验证,对其品质特性进行分析与探讨。结果表明:4个品种葡萄成熟果实的品质指标品种间差异较大。无核寒香蜜品种果实的可溶性固形物含量和可滴定酸含量较高,香悦维生素C含量高,硬度大。4个品种葡萄成熟果实中共检测到87种挥发性物质,主要成分为醇类、酯类和醛类。不同品种间主要挥发性物质存在差异。香悦、玫瑰香、金手指和无核寒香蜜葡萄品种果实中挥发性物质相对含量最高的物质分别为乙酸乙酯、沉香醇、青叶醛和乙酸乙酯,呈现出的风味分别为草莓香味、浓郁玫瑰香味、新鲜绿叶香味和草莓香味。利用电子鼻对不同品种葡萄果实挥发性物质进行主成分分析和线性判别分析,可以将4个品种葡萄完全区分开。因此,本试验明确了不同品种葡萄果实采后品质的差异,电子鼻结合GC-MS方法可以有效评价其挥发性物质差异。     

葡萄贮藏中的灰霉病害及其防治

随着生产的发展和人民生活水平的提高,鲜食葡萄的贮藏变得越来越重要。近年来灰霉病已成为葡萄低温和常温贮藏以及长途运输中最严重的病害,在田间也时有发生。本文对灰霉病原的侵染途径、侵染条件、发病症状、发病原因、防治措施进行了综述。     

葡萄砧木新品种—华佳8号的选育

利用华东葡萄(Vitispseudoreticulata)与佳利酿(Carignane)杂交,从其后代中选出了一个生长势极强的单株,其根系发达,扦插育苗成活率为45% ～55.8% 。作为砧木与藤稔等葡萄品种嫁接亲和力强,试验表明,华佳8 号与藤稔这一砧穗组合的幼树生长势极强,总生长量是常规巨峰砧藤稔的3.7 倍,有明显的乔化作用。5 年累计亩产量是巨峰砧的1.5 倍,果穗与果实品质均超过巨峰砧。笔者认为华佳8 号是藤稔葡萄较为理想的砧木品种。     

Is weight loss in ripening grape berries cv. Shiraz caused by impeded phloem transport?

Berry shrinkage in ripening grapes cv. Shiraz is systemic within a given grapevine and coincident between grapevines in any given season. In this present study on weight loss in ripening berries, ripening curves of non-solutes per berry (largely water) were similar to curves for berry weight (as a function of time). Both sets of curves were equivalent with respect to timing of maximum weights and subsequent rates of weight loss. However, curves of solutes per berry (largely sugar) increased steeply up to the time of maximum berry weight, then slowed and plateau-ed. We suggest that phloem sap is the sole source for water and solutes that enter grape berries subsequent to veraison, and accumulate until maximum berry weight. We further suggest that phloem flow becomes impeded at maximum berry weight.
As berry ripening proceeds, continuation of berry transpiration leads to berry shrinkage and a concentration of solutes; i.e. any increase in juice Brix depends on shrinkage. One implication is that assimilates enter a berry up to the onset of shrinkage, whereafter accumulation of non-anthocyanin glycosides (including glycosides of flavour compounds) depends upon their synthesis in situ.     

砾石土质条件下葡萄滴灌生育期土壤含水率变化规律研究

为探究酿酒葡萄在砾石土质条件下的土壤含水率变化规律及合理灌溉制度,选取贺兰山东麓砾石土典型试验区,以五年生赤霞珠品种为研究对象,设计2 550、2 850、3 225、3 600 m3/hm24个不同定额的灌水处理,应用TDR土壤水分剖面仪和土壤水势仪,监测生育期滴灌前后不同土层含水率与水势变化,针对监测数据从灌水处理整体与单个生育期不同角度进行分析,研究酿酒葡萄在砾石土条件下不同滴灌定额土壤含水率变化规律,最终提出生育期适宜灌溉制度。研究结果表明:随着灌溉定额的增加,土壤含水率在0~40cm土层范围内变化较明显;不同深度土层土壤水势变化规律与灌溉定额的大小有关;1m深土壤水分蓄存比并不是随着灌水量的增加而增大,而是当灌水量达到某一定额时,随着灌水量的增加,土壤水分蓄存比减小,砾石土单次灌水量高于300 m3/hm2时,土壤水分蓄存比较低,易产生深层渗漏。     

Grape,apple and pineapple juice characterisation and detection of mixtures

Several multivariate statistical methods (principal component, cluster, stepwise discriminant and multiple linear regression analysis) were applied to analytical data obtained by conventional methods and to analytical data for free amino acids, in an attempt to distinguish between grape, apple and pineapple juice. Analysis for methionine, proline, asparagine, arginine and glutamic acid made it possible to differentiate among the 34 samples of grape, apple and pineapple juices studied. Multiple linear regression analysis of computer-simulated mixtures of grape and apple juices made it possible to detect the proportion of each fruit within the blend.