花椰菜新品种———津品55     

李素文  孙德岭  温媛  王公恕  张宝珍  方文惠  赵前程  刘莉莉 《园艺学报》2005,32(1):183-183

 ‘津品55’为秋中早熟花椰菜一代杂种, 成熟期约60 d, 内叶合抱护球, 花球较紧, 洁白,单球质量1.0 kg左右, 产量30000 kg/hm² 左右, 比对照品种‘丰花60’增产26.0% ～43.3% , 生长势强,抗病性好。  相似文献   

番茄果实采后一氧化氮处理对活性氧代谢的影响   总被引：13，自引：1，他引：13  

张少颖  任小林  饶景萍 《园艺学报》2005,32(5):818-822

 以番茄品种‘百利’为试材, 研究了NO处理对其采后活性氧代谢的影响。结果表明: NO处理可推迟果实呼吸和乙烯高峰的出现, 抑制O·₂ 和H₂O₂ 的累积, 保持了贮藏后期SOD、CAT、POD、APX 较高的活性以及GSH和AsA含量的较高水平, 延缓了MDA含量和膜相对透性的升高, 降低膜脂过氧化程度, 延缓了果实衰老。  相似文献   

Pregnancy Rates in Repeat-breeder Heifers Following Multiple Artificial Inseminations during Spontaneous Oestrus     

Bhupender Singh  Fernando Saravia  Renée B?ge  Heriberto Rodríguez-Martínez 《Acta veterinaria Scandinavica》2005,46(1):1-12

Hormonal asynchronies during oestrus, related to the presence of suprabasal plasma-progesterone (P4) concentrations and a delayed ovulation, interfere with the fertility of repeat-breeder heifers (RBH). Since tubal dysfunction can occur in connection with hormonal asynchronies and constrained availability of fertile spermatozoa at the time of ovulation, the present study tested the hypothesis that frequent sperm deposition from onset of oestrus to ovulation may improve pregnancy rates in RBH. Five RBH and five virgin heifers (VH; controls) were repeatedly artificially inseminated (AI) at 6 h intervals from onset of oestrus to spontaneous ovulation. Hormone analyses revealed suprabasal P₄ concentrations and a delay in the occurrence of the luteinising hormone (LH) surge, but a normal cortisol profile in RBH. Compared with controls, RBH presented longer interval from onset of oestrus to ovulation, and therefore, received more AIs. Pregnancy rates in RBH reached control levels (60%; NS), indicating that the hypothesis might be correct. Pregnancy rates in VH were below the expected range, presumably attributed to a deleterious influence of the frequent handling. The study suggests that pregnancy rates can be improved in RBH by frequent AI in relation to spontaneous ovulation. However, this practice of repeated manipulations, while seeming not to show adverse effects, lacks practicality for routine use.  相似文献   

秋水仙素对四季桔多倍体的诱导效应     

郑君强  罗筱玉  方小燕 《福建果树》2005,(4):3-5

以四季桔（Fortunella calamondin）种子为外植体，研究了秋水仙素对多倍体诱导的影响，结果表明：将种子用秋水仙素溶液漫渍比直接接种在含秋水仙素的培养基上，诱导多倍体的效果更好，用0．2％秋水仙素溶液浸渍种子12．75h，诱导率最高，达14．4％；在含0．2％秋水仙索的培养基上培养50d，诱导率为9．8％；变异植株叶片变大，茎变粗，有少量植株出现三出复叶突变；变异植株的气孔明显大于二倍体植株，气孔密度降低。  相似文献   

蝴蝶花的组织培养和根状茎的诱导     

赵宏波  陈发棣  房伟民  张聂  郭维明 《园艺学报》2005,32(3):556-556

蝴蝶花(IrisjaponicaThunb.)是鸢尾科鸢尾属的多年生常绿宿根草本植物,地下有横走的根状茎;耐荫,是良好的耐荫地被植物。试验于2003年10月至2004年5月进行。选择健康的蝴蝶花植株,取地下的根状茎,选带节的茎段作为外植体,用洗洁精溶液浸泡4～5min,采用75%乙醇60s结合0.1%HgCl212min进行灭菌。根状茎在培养基MS 6BA1.0mg·L-1 KT2.0mg·L-1 NAA0.1mg·L-1,25℃下黑暗培养,腋芽出芽率达65.4%。黑暗比光照更有利于腋芽的萌发,可能是由于蝴蝶花是阴性植物;在自然条件下其根状茎的生长和顶芽的萌发处于暗环境,离体条件下黑暗培养更符合其…  相似文献   

从核心种质的研究入手开展农作物优异基因的挖掘利用     

李锡香  方智远 《中国蔬菜》2005,(Z1):1-7

针对植物种质资源收集保存和研究利用中的热点问题,在综述植物核心种质研究进展的基础上,阐述了广泛开展核心种质研究的意义,提出了从核心种质研究入手开展优异基因挖掘的策略。同时,介绍了我国基于核心种质研究的优异基因挖掘利用的现状、问题及发展需求。  相似文献   

Second-intention repair in the horse and pony and management of exuberant granulation tissue.     

Jacintha M Wilmink  P René van Weeren 《Veterinary Clinics of North America: Equine Practice》2005,21(1):15-32

Second-intention repair is faster in ponies than in horses and faster in body wounds than in limb wounds. To a large extent, the differences between horses and ponies can be explained by differences in the local inflammatory response, which are a result of the functional capacity of leukocytes. In ponies, leukocytes produce more inflammatory mediators,resulting in better local defense, faster cellular debridement, and a faster transition to the repair phases, with more wound contraction. In horses,leukocytes produce fewer mediators, initiating a weak inflammatory response, which becomes chronic. This inhibits wound contraction and gives rise to the formation of exuberant granulation tissue. The anatomic environment that influences the inflammatory response and wound contraction most probably determines the differences between body and limb wounds. In body wounds, better perfusion results in faster initiation of the inflammatory phase. The weaker local resistance results in a greater degree of contraction. In limb wounds, particularly of horses, the initial inflammatory response is weak and wound contraction is restricted. Both factors give rise to chronic inflammation, which further inhibits wound contraction and promotes exuberant granulation tissue. The high incidence of exuberant granulation tissue in limb wounds of horses can thus be explained by the chronicity of the inflammatory response as well as by the common use of bandages during treatment. Chronic inflammation is often not recognized as a cause of exuberant granulation tissue. It must be prevented and treated to promote the healing process. Bandages and casts stimulate the formation of exuberant granulation tissue; however, they are advantageous in many respects and play an important role in support of the overall healing process.  相似文献   

乌梁素海生态恢复机理与工程技术的研究   总被引：2，自引：1，他引：2  

尚士友  杜健民  厚福祥  申庆泰  王丽敏 《干旱区资源与环境》2003,17(6):50-54

在我国干旱区典型草型湖泊—乌梁素海设立试验基地 ,进行生态恢复工程试验研究。研究表明 :乌梁素海受富营养化影响 ,正在向芦苇沼泽—碱蓬盐化草甸—白刺荒漠方向演化。生态恢复机理是 :( 1 )减少大型水生植物有机氮、磷向底质的沉降 ,削弱内源性营养物负荷的积累与储备 ;( 2 )减少大型水生植物死亡后矿化成氨态氮 ;( 3)控制底质中有机氮向水体释放生成氨态氮。采用机械化方式收割大型水生植物转移营养盐 ,抑制生物促淤效应以及对芦苇区进行园田化生态管理是乌梁素海生态恢复的关键技术 ,也是乌梁素海环境与资源持续发展的核心问题  相似文献   

内蒙古地区提高天然降水利用率实用技术及其评价     

白美兰  沈建国 《干旱区资源与环境》2003,17(6):113-118

本文针对内蒙古地区水资源短缺 ,旱灾发生频繁的现状及天然降水利用效率不高的特点 ,结合国内外现有的科研与技术成果 ,根据地处干旱、半干旱地区内蒙古的气候特点 ,提出提高天然降水利用率的各种实用技术方法。并利用地理信息技术 ,根据各种实用技术方法的指标要求 ,结合内蒙古的地形、坡度状况、土壤类型和气象条件 ,在雨养农业区进行实用技术方法的优化分区 ,区划出适宜区域。  相似文献   

基于不同尺度的干旱区城市景观生态研究--以陕西榆林市为例   总被引：6，自引：0，他引：6  

张艳芳  任志远 《干旱区研究》2003,20(3):175-179

从区域与城市两个尺度水平 ,对毛乌素沙漠南缘的榆林市城市景观进行研究认为 :在大尺度水平上 ,区域景观生态特征对城市景观特征具有一定的控制作用 ,而城市景观强大的功能流对区域景观产生干扰作用。城市景观的空间扩展与演化 ,既受区域景观特征的影响 ,也是区域景观演化的一个有机构成部分 ;在小尺度空间上 ,景观功能区、景观斑块与廊道的格局与功能 ,对城市景观格局动态以及维持城市景观多样的生态功能具有重要意义。在不同的利益追求下形成的景观文化 ,将深刻地影响到区域与城市景观演化的方向与过程。  相似文献