Genetic Relationships among Prunus mume var. pendula Using AFLP Markers

Genetic relationships among Prunus mume var. pendula were studied by using AFLP markers. 18 accessions representing 14 cultivars ofPrunus murne var. pendula were selected from the germplasm collection at the Research Center of China Mci Flower. Seven Mse I-EcoR I AFLP primer combinations revealed 450 legible bands, and 269 of which were polymorphic markers. A similarity matrix was prepared using the simple matching coefficient of similarity and Nei‘s (72) distance coefficient. A UPGMA dendrogram demonstrated the genetic relationships of the cultivars. The information given by AFLP markers was basically consistent with the morphological classification and the evolutionary history of the morphotypes, and roughly supported the new revised classification system for Chinese Mci Cultivars. But there were still several exceptions: 1) the ‘Guhong Chuizhi‘ inserted between the ‘Tiaoxue Chuizhi‘ and the ‘Danfen Chuizhi‘; 2) the ‘Wufu Chuizhi‘ kept off the Pink Pendant Form, and the ‘Moshan Chuizhi‘ was removed from Viridiflora Pendant Form; 3) the ‘Danbi Chuizhi‘ and the ‘Shuangbi Chuizhi‘ of Viridiflora Pendant Form got together well but fell within the Pink Pendant Form.     

河南桧柏嫩枝“全光雾”扦插育苗试验初报

河南桧柏采用嫩枝“全光雾”扦插育苗，试验表明：对难生根珍贵树种用此法育苗可大大缩短育苗周期，提高苗木产量和质量，应大力推广此种育苗方法。     

Dynamics of maize grain drying in the high latitude region of Northeast China

A high grain moisture content at harvest has been an important problem in the high latitude region of Northeast China, and it is closely related to the genotypes of varieties, local meteorological factors and planting management. However, delayed harvest at a low temperature could not effectively reduce the grain moisture content. In this study, we continuously observed the grain drying during the late stage of different maturing types of maize varieties in Daqing, Heilongjiang Province, China in 2016 and 2017. A two-segment linear model was used to analyze the different stages of the drying processes: 1) Two-segment linear model fitting can divide the grain drying process of all varieties into two separate linear drying processes with different slopes. 2) During the rapid drying stage, the drying was faster at a higher temperature. The rate of slow drying was influenced by air vapor pressure. 3) The moisture content and meteorological factors when the drying rate turns from one stage into the other were not consistent between varieties and years. After entering the frost period, temperatures below 0°C will significantly reduce the rate of grain drying. 4) Due to the short growth period of early-maturing varieties, the drying time was prolonged, and the grain moisture content was lower than that of the mid-late maturing varieties. Local meteorological conditions do not allow the drying of mid-late maturing varieties to achieve a lower moisture content. When the temperature falls below 0°C, the drying rate of grain decreases markedly. Therefore, one feasible way to solve the problem of high moisture content is to replace the early-maturing varieties and implement the corresponding cultivation techniques.     

高通量测序分析蚕豆种子内生细菌的多样性

为了分析蚕豆种子内生细菌的多样性,采用Illumina MiSeq高通量测序技术,从日本大白皮（S18P23.1、 S18P23.2）和启豆2号（S18P24.1、S18P24.2）的种子获得16S RNA V3～V4区有效序列133 855条。将高于97％相似度的序列划分为一个操作分类单元（operational taxonomic unit, OTU）,优化后得到1 598个OTUs。内生细菌种群分析结果表明,拟杆菌门（Bacteroidetes,丰度为30%～33%）、变形菌门（Proteobacteria, 23%～25%）、厚壁菌门（Firmicutes, 23%～25%）和放线菌门（Actinobacteria, 5%～7%）为两个蚕豆品种共有的优势菌门,但属水平的优势菌群在供试蚕豆种子中均有差异。这些结果表明,蚕豆种子具有丰富的内生细菌资源,含有多种具有益功能性状的细菌类群,值得进一步跟踪研究这些益生菌在蚕豆种植到土壤后的变化规律;启豆2号种子中益生菌的种类和丰度高于日本大白皮,值得进一步分离和研究这些益生菌的益生或促生特性,筛选获得在食品和生物肥料等领域有应用潜力的菌株。     

Numerical Simulation on Drying Characteristics of a Combined Microwave-convection Process

Combined microwave-convection drying characteristics are investigated by numerical simulation. Combined microwave-convection drying has advantage of swift drying and sterilization. Based on qualitative analyses on the mechanism of combined microwave-convection drying, the differential equations are established and the numerical simulation method is described. The humidity, vapor pressure and temperature, along the radius in a spherical pill, are calculated by the numerical simulation during drying process. The calculation results show the relationship between humidity, vapor pressure, temperature and drying time, and that drying process is greatly influenced by input microwave power. The calculation results are good consistent with the experimental datum.     

水稻不同穗型品种穗颈节间组织与籽粒充实特性的研究

本文用7个不同穗型的中稻品种,研究了重穗型、中穗型、轻穗型品种的穗颈节间组织特性及其与籽粒充实的关系.结果表明:穗颈节间维管束数目,维管束、韧皮部面积,茎横切面、茎壁、髓腔面积,均是重穗型>中穗型>轻穗型品种.穗颈节间输导组织特征与空壳率的大小无关,但它是籽粒充实的重要前提和解剖学基础.穗颈节间茎的粗度、茎壁的     

加强农业院校化学基础教学改革提高人才素质

以农业院校化学基础教育教学改革为对象,针对农业高等教育中化学教学所存在的问题,在教学观念、教学模式及教学方法方面进行了改革,提出应利用现代教学手段培养学生的学习兴趣,加强基础课和综合实验教学,促进学生创新素质的培养。     

作物品种区域试验多年资料联合分析法的应用

用作物品种区域试验多年资料联合分析方法的计算机程序对 2 0 0 1～ 2 0 0 2年度国家玉米品种区域试验的部分资料进行分析。结果表明 ,该程序不仅可以进行方差分析 ,而且可以计算品种、试点和品种试点组合的最小二乘均数 ,并可对其差异显著性进行检验。     

多物种共存系统中蜘蛛对稻虫的控制作用

 运用二次通用旋转组合设计统计方法 ,选择稻田生态系统中天敌蜘蛛优势种拟水狼蛛 (Piratasubpirati cus)、粽管巢蛛 (Clubionajaponicola)、锥腹肖蛸蛛 (Tetragnathajaponica) 及水稻主要害虫褐飞虱 (Nilaparvatalu gens) 和稻赤斑沫蝉 (Callitettixversicolor) 组成多物种共存系统 ,探讨蜘蛛对稻虫的控制作用 ,分析天敌之间、害虫之间以及天敌与害虫之间的相互作用关系 ,获得了 6个天敌对害虫的捕食量模型。对模型进行主效分析表明 ,害虫密度的大小对天敌的总捕食量影响较大 ,其中又以褐飞虱对捕食量的影响最大。天敌中对捕食量作用最大的是拟水狼蛛 ,其次是锥腹肖蛸和粽管巢蛛。分析天敌间的交互作用表明 ,天敌个体大、活动能力强、生态位窄及其重叠值高、捕食量大 ,它们的种内种间干扰程度也大 ,特别是粽管巢蛛和锥腹肖蛸蛛各自的种内干扰、拟水狼蛛与粽管巢蛛的种间干扰作用十分明显。最后讨论了天敌蜘蛛能有效控制害虫的最大密度 ,以及在该害虫密度下各种天敌密度的最佳组合