1-MCP和DPA对砀山酥梨黑皮病的抑制效果

【目的】探讨1-MCP和DPA对砀山酥梨黑皮病的抑制效果及其可能的机理,为梨的黑皮病控制提供技术参考和理论依据。【方法】以砀山酥梨为材料,在果实冷藏(2±0.5℃)前,分别采用1000μL.L-1、2000μL.L-1的DPA溶液浸泡1min和0.5μL.L-1的l-MCP气体处理12h,定期对果实部分采后生理指标进行测定,并在贮藏末期对其黑皮病发病情况进行观察统计。【结果】1000μL.L-1、2000μL.L-1的DPA溶液和0.5μL.L-11-MCP处理,显著地抑制了果皮α-法尼烯、共轭三烯、总酚、MDA的含量、细胞膜透性的增加和PPO活性的升高,并极其显著地抑制了果实在贮藏期黑皮病的发生,延迟了其在货架期的发病。【结论】采后适宜浓度的1-MCP和DPA处理,均能显著地抑制和延缓砀山酥梨冷藏期和货架期黑皮病的发生,但二者的作用机理可能不同。     

核桃举肢蛾为害特点与综合防治技术

通过近年对本县核桃举肢蛾发生为害情况的调查研究,总结出蓝田县核桃举肢蛾为害特点与综合防治技术,为科学有效防治核桃举肢蛾提供参考。     

Genetic variants of HvGlb1 in Tibetan annual wild barley and cultivated barley and their correlation with malt quality

Improvement of malt quality is the most important objective in malt barley breeding. The current experiments investigated the variation of malt quality characters among barley genotypes and the difference in genetic variants of HvGlb1, encoding β-glucanase isoenzyme I, between Tibetan annual wild barley and cultivated barley. The correlation between the gene variants and malt quality showed that there was a large difference in the four malt quality parameters, i.e. Kolbach index, diastatic power (DP), viscosity and malt extract, among the analyzed barley cultivars. Kolbach index was negatively and positively correlated with viscosity and malt extract, respectively, while malt extract was negatively correlated with viscosity. Malt β-glucan content was a major determinant of malt quality, and was significantly correlated with Kolbach index (−0.633), malt extract (−0.333) and viscosity (0.672). On the other hand, malt β-glucan content was mainly controlled by malt β-glucanase activity. The correlation analysis showed that the HvGlb1 gene was correlated with malt β-glucan content and three of four main malt quality parameters, except DP. In addition, we also found that the HvGlb1 of Tibetan barley had wider diversity in haplotype than that of the cultivated barley, supporting the hypothesis that Tibet is one of the original centers of cultivated barley.     

果园夏季杂草数量生态学研究

2009年夏季采用1m×1m样方法对山西省太谷县的山西省农业科学院果树研究所果园夏季杂草群落进行调查,分析不同样地杂草群落的发生规律,并在此基础上,采用双向指示种分析法（CTWINS—PAN）和除趋势对应分析法（DCA）对群落进行了数量分类和排序分析。调查共发现73种杂草,属于27科62属,其中入侵杂草最多的为菊科（14种）和禾本科（11种）。TWINSPAN等级分类将该果园66个样方划分为11个群丛,分类结果较好地反映了该果园夏季杂草群落类型与环境梯度之间的关系,并在DCA二维排序图上得到较好的验证,即DCA第1轴主要反映了土壤水分的变化情况,从左到右土壤水分逐渐增多;第2轴主要反映了土壤养分的变化趋势,从上向下土壤养分逐渐减少,说明杂草群丛的分布格局与土壤水分和养分的密切关系,组成果园夏季杂草的优势种群能客观反映群落的生境特征．     

免疫PCV2疫苗对生长猪增重与健康的影响

在猪圆环病毒2型(PCV2)阳性猪场仔猪免疫PCV2灭活疫苗,无论是小群试验还是大群试验,免疫均能提高猪的成活率,降低猪因PCV2感染引起相关疾病的发病程度,提高猪群平均增重速度。40日龄和56日龄免疫组的PCV2抗体极显著低于对照组(P0.01),而85日龄时,一次免疫组的抗体快速升高超过对照组,2次免疫仍较低,差异极显著(P0.01)。     

红芪多糖的体外抗氧化活性研究

[目的]研究红芪多糖3（HPS-3）的抗氧化活性。[方法]在体外化学模拟条件下,研究HPS-3对超氧阴离子（O2-.）、羟基自由基（.OH）、DPPH和过氧化氢（H2O2）的清除作用。[结果]HPS-3具有一定的清除自由基的能力,在0.05～5.00mg/ml浓度范围内,对O2-.、H2O2、.OH及DPPH的最大清除率分别为55.92%、59.32%、53.69%和87.66%,且呈一定的量效依赖关系。[结论]红芪多糖在体外有直接的抗氧化能力。     

Mechanical properties assessment of Cunninghamia lanceolata plantation wood with three acoustic-based nondestructive methods

The objectives of this study were to establish the method of evaluating wood mechanical properties by acoustic nondestructive testing at standing trees and at logs of a Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) plantation, and to compare three acoustic nondestructive methods for evaluating the static bending modulus of elasticity (MOE), modulus of rupture (MOR), and compressive strength parallel-to-grain (σ_c) of plantation wood as well. Fifteen Chinese fir plantation trees at 36 years of age were selected. Each tree was cut into four logs, for which three values of dynamic modulus of elasticity, i.e., E _sw, of the north and south face based on stress waves to assume the measuring state of the standing tree, E _fr, longitudinal vibration, and E _us, ultrasonic wave, were measured in the green condition. After log measurements, small specimens were cut and air-dried to 12% moisture content (MC). Static bending tests were then performed to determine the bending MOE and MOR, and compressive tests parallel-to-grain were made to determine σ_c. The bending MOE of small clear specimens was about 7.1% and 15.4% less than E _sw and E _us, respectively, and 11.3% greater than E _fr. The differences between the bending MOE and dynamic MOE of logs as determined by the three acoustic methods were statistically significant (P < 0.001). Good correlation (R = 0.77, 0.57, and 0.45) between E _sw, E _fr, and E _us and static MOE, respectively, were obtained (P < 0.001). It can be concluded that longitudinal vibration may be the most precise and reliable technique to evaluate the mechanical properties of logs among these three acoustic nondestructive methods. Moreover, the results indicate that stress wave technology would be effective to evaluate wood mechanical properties both from logs and from the standing tree.     

几种断奶仔猪饲料原料系酸力的比较研究

试验研究了不同工艺形式及不同营养水平的几种断奶仔猪饲料原料的系酸力水平,结果表明:普通玉米与膨化玉米、直火工艺鱼粉与蒸汽鱼粉系酸力差异不显著(P0.05),普通豆粕蛋白水平越高,系酸力越高(P0.01),高蛋白乳清粉系酸力极显著高于低蛋白乳清粉(P0.01),高蛋白水平发酵豆粕(CP48.03%)系酸力低于普通豆粕(CP46.4%()P0.01),膨化大豆(CP39.13%)系酸力极显著低于其他形式豆粕系酸力(P0.01),血浆蛋白粉系酸力极显著高于鱼粉和乳清粉(P0.01),矿物质饲料原料有较高的系酸力。     

鸡传染性喉气管炎病毒的分离和TK基因鉴定

从临床表现以呼吸困难、喉头出血为主要特征的某蛋鸡场患鸡喉头和气管等组织分离到一株病毒.该分离毒无血凝特性,应用检测ILTV TK基因的PCK能从分离毒中扩增出大小为427 bp的特异性目的片段.测序结果与GenBank收录的ILTV不同毒株序列的同源性为100%.结果初步表明该分离毒为鸡传染性喉气管炎病毒(命名为ILTV-FJ).     

六种植物生长调节剂对香根草生长发育的效应研究

围绕种苗繁殖技术和实际应用需求,初步研究了6种外源植物生长调节剂对香根草发育过程中形态指标的影响。结果表明:多效唑矮化促蘖效果明显,除一级根数和根茎比指标外,其它根系指标不如对照处理。矮壮素具有一定的促蘖效果,持续时间只有3个多月,但矮化效果不明显。除根茎比指标外,矮壮素处理的其它根系指标均不如对照处理。