南方红豆杉扦插繁殖技术研究——Ⅰ.基质、季节与生物措 施对扦插繁殖的影响

试验研究基质、季节和生物措施对南方红豆杉扦插生根、扦插苗生长和叶绿素含量的影响结果表明,以河沙和珍珠岩按8∶2混配苗床基质最佳,其绿苗率、生根率及成苗率分别为86 .0 %、84 .3%和81.7% ,显著高于其他3种苗床基质;其次为河沙和火烧土混配苗床基质>黄土>单一河沙苗床基质。季节和生物措施效应显示第4季度为扦插最佳时期,扦插效果显著优于其他季节,且扦插后拌种黄豆显著优于未拌种黄豆对照组     

穴盘播种控制器中的多任务分析与实现

在穴盘播种控制器的软件系统开发时，通过对穴盘播种控制器中存在的任务进行分析，运用实时系统前后台编程方式，合理使用单片机的中断系统，进行了播种器的控制软件设计。最后对软件性能进行了分析。经实际运行结果表明，该软件系统可以很好地满足播种器的实际工作要求。     

白皮松容器育苗技术

本文介绍了白皮松容器育苗技术,包括育苗地选择、作床、育苗容器准备、营养土配制、种子处理、播种、苗期管理、立枯病防治等技术要点。     

腐殖酸对花生连作地土壤真菌群落结构的影响

土传病害的绿色防控是当前农业、生态和环境领域中为建立资源节约型、环境友好型病虫害可持续治理技术体系的重要组成部分。将来自藓类泥炭和风化煤的腐殖酸添加至两个花生种植年限的土壤中（1年和6年）,进行室内恒温培养。对土壤真菌进行内部转录间隔区（internal transcribed spacer,ITS）测序,运用非参数多因素方差分析（PerMANOVA）、相关性分析等方法阐释腐殖酸对土壤真菌群落的影响。结果表明：腐殖酸的添加显著影响了培养94 d以后的土壤真菌群落结构,而添加量对4个培养时间点的土壤真菌群落结构均可产生显著影响;同时腐殖酸显著改变了部分真菌属的相对丰度。腐殖酸对土壤真菌功能的影响,主要表现为显著改变了土壤中真菌功能营养型的组成。其中,随着腐殖酸添加量的增加,土壤植物病原菌的相对丰度均显著降低;相关性分析表明腐殖酸添加量与致病菌镰刀属（Fusarium spp.） 和丝核菌属（Rhizoctonia spp.）的相对丰度呈显著负相关,而与拮抗菌青霉属（Penicillium spp.）的相对丰度呈显著正相关。本研究表明,特定腐殖酸在适当添加量下可显著改变花生地的土壤真菌群落结构和功能营养型组成,尤其是降低了土壤中植物病原菌的相对丰度,但影响程度因花生种植年限的长短而异。本研究结果为腐殖酸生态功能应用拓展提供了理论依据,为土传病害绿色防控技术的研发提供新的视角。     

信息时代英语论文写作能力的培养

阐明了培养专业英语论文写作能力对大学生的重要性,对专业英语论文写作课程的设置进行了探讨。     

Study on Effects of Different Medium Compositions on Growth and Seedling Quality of Two Tomato Varieties Under Greenhouse Conditions

This research was conducted to investigate the effects of different medium compositions on physicochemical properties and the growth of two tomato varieties. Five treatments were applied, combining medium composition with rice husk ash (RHS) and coconut fiber (CF) with the following proportions: 1/3 Peat moss + 1/3 rice husk ash + 1/3 coconut fiber (T1); 1/3 Vermicompost + 1/3 rice husk ash + 1/3 coconut fiber (T2); 1/3 Cattle manure compost + 1/3 rice husk ash + 1/3 coconut fiber (T3); 1/3 Chicken manure compost + 1/3 rice husk ash + 1/3 coconut fiber (T4); 1/3 Hog manure compost + 1/3 rice husk ash + 1/3 coconut fiber (T5). The results demonstrated that between pH, electrical conductivity (EC) value, and nutrient content in the media, there was a significant difference that led to different concentrations of total macro- and micronutrients in the shoots of both varieties. In addition, the root weight, shoot weight, and root volume were affected by medium composition for two varieties in seedling stage. A mixture of cattle manures composted with RHS and CF under the rate (1:1:1 by volume), respectively, gave the highest value of germination rate, plant height, leaf number, and plant biomass. Medium composition significantly influenced the germination rate and elongation of seedlings, specifically for each tomato variety. Therefore, cattle manure compost as a medium supplement improves seedling quality and growth of the two tomato varieties.     

降水量与安康飞播油松成苗效果关联分析

为研究降水量对飞播造林成苗量和有苗样方频度作用的区域变化,在汉中降水量与飞播油松成苗效果研究的基础上,利用1997年安康飞播油松成苗期有苗样方频度和成苗量调查数据,采用相关分析法和逐步回归模型分析法,分析成苗效果与降水量的关系。结果表明,安康飞播成苗效果与年降水量呈显著负相关,而汉中呈极显著的正相关。两地成苗效果均与1月、6月和9-12月降水量呈负相关,与3-5月和8月降水量呈正相关,但相关度有差异。安康成苗效果与2月和7月降水量相关不显著,而汉中与2月降水量呈极显著的负相关,与7月呈极显著的正相关。充分说明飞播油松成苗效果不仅取决于当地年降水量,而且与当地降水量的分布密切相关。与汉中结果一致,在当地降水量范围内,RPA模型值均大于对照,证明RPA拌种能提高飞播后单位降水量的油松有苗样方频度和成苗量,且作用稳定。     

半干旱风沙区黄柳幼苗生长发育对沙埋的响应

以科尔沁沙地黄柳(Salix gordejevii)幼苗为研究对象,通过0 cm,10 cm,20 cm和40 cm 4个沙埋处理,研究其生长发育对沙埋的响应。结果表明：随着沙埋深度的增加,黄柳幼苗的死亡率增加,存活率下降。沙埋对黄柳幼苗的株高、相对高度增长率,分配到根、茎、叶的生物量和根冠比有显著影响,对绝对高度增长率和生物量无显著影响。轻度沙埋有利于黄柳幼苗高度增加,随着沙埋深度的增加,株高依然增加,相对高度生长率却下降。轻度沙埋使黄柳幼苗的生物量较多地分配到根,随着沙埋深度的增加,较多的生物量分配给地上部分,根冠比下降。说明黄柳幼苗可通过加快茎的生长或改变生物量的分配等方式维持光合作用能力,增加对沙埋的抵御能力。     

The conserved global regulator VeA is necessary for symptom production and mycotoxin synthesis in maize seedlings by Fusarium verticillioides

The veA or velvet gene is necessary for biosynthesis of mycotoxins and other secondary metabolites in Aspergillus species. In addition, veA has also been demonstrated to be necessary for normal seed colonization in Aspergillus flavus and Aspergillus parasiticus. The present study shows that veA homologues are broadly distributed in fungi, particularly in Ascomycetes. The Fusarium verticillioides veA orthologue, FvVE1, is also required for the synthesis of several secondary metabolites, including fumonisin and fusarins. This study also shows that maize plants grown from seeds inoculated with FvVE1 deletion mutants did not show disease symptoms, while plants grown from seeds inoculated with the F. verticillioides wildtype and complementation strains clearly showed disease symptoms under the same experimental conditions. In this latter case, the presence of lesions coincided with accumulation of fumonisins in the plant tissues, and only these plant tissues had elevated levels of sphingoid bases and their 1-phosphate derivatives, indicating inhibition of ceramide synthase and disruption of sphingolipid metabolism. The results strongly suggest that FvVE1 is necessary for pathogenicity by F. verticillioides against maize seedlings. The conservation of veA homologues among ascomycetes suggests that veA could play a pivotal role in regulating secondary metabolism and associated pathogenicity in other fungi.