从野外昆虫体内分离的5株微孢子虫的生物学特性与分子系统发育研究

从广西蚕区的野外昆虫菜粉蝶(Pieris rapae)、桑尺蠖(Hemerophila atrilineata)、斜纹夜蛾(Spodoptera litura)的体内收集到5株对家蚕有一定食下感染力的微孢子虫,通过生物学性状、分子系统发育研究,为其分类鉴定提供依据。来自野外昆虫的5株微孢子虫均具有Nosema属的生物学特性:显微镜下观察形状均呈长卵圆形,与家蚕微孢子虫(Nosema bombycis,Nb)有较明显差异;在生活史的各发育阶段均为双核,以二分裂方式增殖,最后形成双核成熟孢子;与Nb抗血清均产生阳性凝聚反应;超微结构观察均具双核,极丝圈数在12～14圈之间,极丝倾斜角与Nb有差异。根据5株野外昆虫微孢子虫与其它昆虫微孢子虫基于SSU rRNA基因序列构建的系统发育树,以及基于SSU rRNA和rRNA ITS基因序列进行的相似性和遗传距离分析,初步认为5株野外昆虫微孢子虫与家蚕微孢子虫同属异种。     

Influence of Soil Drought on Plant Growth, Assimilation and Dissimilation of CO2 and Accumulation of Photosynthates in Field Bean (Vicia faba L. minor) During Pod Formation and Rapid Pod Growth

Field bean planes cultivar Nadwiślański were submitted to soil drought (30 % of field soil water capacity) for 5 days at the stage of pod formation (A) and of rapid pod growth (B) and then exposed for 20 minutes to ¹⁴CO₂. Radioactivity of leaves, stems, roots, and pods or pod shells and seeds was measured 1, 5, 24 and 48 hours after exposition.
In both stages soil drought reduced by about five times total CO₂ assimilation, mainly owing to lower activity of the photosynthetic apparatus and also, though less so, to reduced leaf growth. Photosynthetic activity referred to the dry weight of the leaves dropped to 22-35% of controls. Accumulation of photosynthetates in generative organs was much less depressed than ¹⁴CO₂ assimilation. 48 hours after exposition to ¹⁴CO₂ of drought treated plants, the contents of ¹⁴C of pods in phase A, and seeds in phase B, amounted to respectively 24% and 36% of assimilated ¹⁴C and equalled 91.5% and 74% of the corresponding values for controls.
The progressive decline of radioactivity in leaves and stems after ¹⁴CO₂ exposition was distinctly correlated to the rise of radioactivity of generative organs both in soil drought treated plants and in controls. Slightly lower values of correlation coefficients in drought treated plants may indicate impairment under drought conditions of synchronization in processes of unloading and accumulation of assimilates.
In plants drought treated in phase A the ability to dissimilate ¹⁴C was reduced to about 59% of that in controls, but when drought was applied in phase B, dissimilation rate was about three times as high.     

Deposition of spray drift behind border structures

Windbreaks present a porous obstacle to the approaching airflow, forcing air to flow through the windbreak at a reduced speed and accelerate over the top. In this research, windbreaks were considered as border structures to mitigate spray drift. Air flows, with an interspace between it, particles are filtered from the flow by deposition on the windbreak. Hence there is a reduction in deposition in the downwind sheltered area (the ‘quiet zone’) behind the windbreak. Peak deposition in the sheltered area can occur at minimum wind speeds. The deposition profiles of spray drift behind various border structures were measured. In the first part, drift tests were performed in a wind tunnel. Artificial screens with various heights and open areas were tested. A row of plastic Christmas trees and natural canopies were also tested. Subsequently, drift experiments were performed under field conditions in a grassland with the artificial screens and a row of Fagus sylvatica trees. The artificial screens reduced spray drift deposition in the sheltered region, but significant deposition peaks were found behind the screens. The natural structures had potential to reduce drift deposition when their height was at least equal to the height of the spray nozzle(s). The drift deposition at short distances behind the natural structures was higher than deposition behind artificial structures, but conversely peaks in deposition in sheltered areas were not created by the natural structures.     

Improving the Field Emergence Performance of Super Sweet Corn by Sand Priming

Abstract

A priming method called sand priming was developed using sand as a priming solid matrix. The effect of sand priming on improving the field emergence performance of five super sweet corn cultivars was investigated. Sand priming significantly improved field emergence performance of all super sweet corn cultivars, and there was marked improvement by priming at 20ºC for 24 hr. After sand priming at 20ºC for 24 hr, field emergence percentage (FEP) of “Green Superman”, “Huatian 1”, “Yangtian 1”, “Mitian 8”, and “Chaotian 43” was increased by 52.1%, 37.5%, 38.0%, 40.9%, and 33.3%, respectively. Their field emergence speed (FES) was 2.3, 1.8, 2.0, 2.0, and 1.8 times of the control, respectively. To further elucidate the effect of sand priming on improving the field emergence performance of super sweet corn, we analyzed the membrane system integrity, α-amylase activity and protein content. Sand priming at 20ºC for 24 hr improved membrane system integrity and α-amylase activity in all super sweet corn cultivars. Furthermore, sand priming at 20ºC for 24 hr accelerated the degradation of embryo protein after 1 d germination in “Green Superman”.     

新疆煤田灭火区植被恢复无土基质配比试验研究——以乌鲁木齐松树头煤矿为例

以乌鲁木齐松树头煤矿为研究对象,采用无土基质配比方法,针对研究区土壤特点,选取选用粘合剂（A）、保水剂（B）、复合肥（C）和秸秆（D）为试验因素,进行无交互作用的正交试验,并对结果进行极差、方差分析影响.结果表明,粘合剂对植物高度、盖度均有显著影响,复合肥对植物盖度有极显著影响,同时也是生物量指标的主要影响因子.各因素主次顺序为C（复合肥）＞B（保水剂）＞A（粘合剂）＞D（秸秆）.基质最优配比方案为A2B1C1D1,即当粘合剂用量为16 g/m2,保水剂为5 g/m2,复合肥为30 g/m2,秸秆为90g/m2时,可获得最佳的植被恢复效果.     

15％茚虫威防治茶假眼小绿叶蝉田间药效试验

田间试验结果表明,选用15％茚虫威（SC）2000、3000、4000倍液,可有效地控制茶园假眼小绿叶蝉的为害,药后14d防治效果分别比10％吡虫啉高48．81％、47．58％、47．77％,经方差分析,达到极显著水平。同时,该药剂在茶园中使用后对蜘蛛等天敌昆虫比较安全。     

Properties of field-sprouted sorghum and its performance in ethanol production

The objective of this research was to investigate physicochemical and biochemical characteristics of field-sprouted grain sorghum and its fermentation performance in ethanol production. Five field-sprouted grain sorghum varieties, which received abnormally high rainfall during harvest, were used in this study. Enzyme activities, microstructure, flour pasting properties, kernel hardness, kernel weight, kernel size, flour size and particle distribution of field-sprouted grain sorghum were analyzed. The effect of germination (i.e., sprouting) on conversion of grain sorghum to ethanol was determined by using a laboratory dry-grind ethanol fermentation procedure. Sprouted sorghum had increased α-amylase activity; degraded starch granules and endosperm cell walls; decreased kernel hardness, kernel weight, kernel size, and particle size; and decreased pasting temperature and peak and final viscosities compared with non-sprouted grain sorghum. The major finding is that the time required for sprouted sorghum to complete fermentation was only about half that of non-sprouted sorghum. Also, ethanol yield from sprouted sorghum was higher (416–423 L/ton) than that from non-sprouted sorghum (409 L/ton) on a 14% moisture basis.     

黑龙江省谷子南繁田间管理技术

对在2009年冬谷子南繁过程中遇到的问题进行了总结,并对南繁过程中需要注意的事项进行了简要阐述,旨为从事谷子南繁工作的人员提供借鉴。     

大通县甘蓝型油菜菌核病重发原因及防治对策

从气候条件、种植方式和田间管理等方面分析了大通县油菜菌核病重发的原因,提出了防治对策。     

远离城镇小尺度的农田土地利用变化分析——以北涝沟村为例

参照参与性农村评估法,对北涝沟村进行了多次实地考察,获取了可靠的土地利用变化的研究资料,应用转移矩阵和生态分析等研究方法对远离城镇的北涝沟村的土地利用变化及未来趋势和生态价值做了分析。结果表明:水田已经成为该村主要的土地利用类型,由旱地向水田的转化是其土地利用变化的主要特点。土地利用结构的变化提高了生态系统的服务功能和价值,并继续向着良好的方向发展。这为远离城镇小尺度的农田土地利用以及生态变化的人为调控和建设提供科学依据。