关中灌区小麦玉米一体化栽培技术

通过生产调查分析和试验研究,针对陕西省关中灌区的生态条件和限制小麦、玉米产量高产的障碍因素,对冬小麦、夏玉米周年农艺措施进行统筹调控,从品种搭配、播期调整、群体构建、水肥运筹等方面,总结形成了以“两旱”（小麦早种、玉米早收）为“两晚”（小菱适期晚播、玉米适期晚收）为主体的关中灌区小麦、玉米一体化栽培技术。     

土壤干旱不同玉米品种水分利用效率差异的生理学原因

研究不同玉米品种水分利用效率差异试验结果表明，陕单911为耗水型品种，农大60为节水型品种，中单2号耗水量表现居中，水分利用效率差异原因分析；水分胁迫对蒸腾的影响要大于光合；陕单911在中度胁迫下Pn(光合速率）大幅度下降，而Tr(蒸腾速率）下降居中，该品种的蒸腾效率下降最多，农大60在中度胁迫下Pn下降最少，而Tr下降最多，该品种的蒸腾效率下降幅度最小，中单2号表现居中，3个品种中度胁迫下根系导水率农大60增加了54．64％，中单2号下降了50．94％，陕单911下降了63．00％；渗透调节能力陕单911＞中单2号＞农大60，叶片失水速度为陕单911＞60＞中单2号。     

Review of Pathogen Identification and Diagnosis Technology of Pinewood Nematode Disease

This article briefly introduced the disease incidence and disservice situation in China. The disease is regarded as cancer in pines for its higher spread and death speed and the difficulty in prevention. Strict quarantine is the main measure on countrol of the disease, for there are many difficulties in the prevention. The most important part of the disease study is the early diagnosis and detection.     

Application of Native Tree Species to Urban Forest

Native tree species plays important roles in theconstruction of urban forest. It bears manyadvantages, such as sufficient cultural context, strongecologic adaptability, high performance-cost ratio andconvenient management. The authors put forwardseveral countermeasures based on the existingproblems. And this paper will be very helpful inunderstanding why native tree species are put in animportant position in the construction of urban forest.The plant is the material basis of constructing urban…     

Restoring Mountain Slope Forests by Strip-cutting Shrubs in the Upper Reaches of Minjiang River, Sichuan, China： A Biodiversity-oriented Silvicuture Experiment

INTRODUCTIONMinjiangRiver,oneofprimarytributariesoftheYangtzeRiver,thatisthelongestriverinChinaandthethirdlongestintheworld,isoriginatedfromtheeasternpartofQinghai-TibetPlateauwherethegeomorphologyismainlycharacterizedbyhighmountainswithdeepvalleys(ZhangRongzu,1992).Becauseslopelandsaccountforalargeproportionofvegetatedareaandthesoillayerisverythininmostcases(ChenGuojie,2000),theupperreachesofMinjiangRiverisidentifiedtobeanunstableandfragileecosystemthatiseasilydeterioratedbyanthropog…     

多酚氧化酶活性基因等位变异在陕西小麦品种中的分布

为了解陕西小麦品种控制多酚氧化酶(Polyphenol oxidase,PPO)活性的主效基因组成.利用PPO 18和PPO 29标记时138份推广品种的PPO-2A和PP(9-2D位点的等位变异进行了分子检测.结果表明,在PPO2A住点,含Ppo-A1a(高PPO活性)和Ppo-A1b(低PPO活性)等位变异类型的品种比例分别为47.1%和52.9%;在PPO2D位点含PpoD1a(中等低PPO活性)和PpcrD1b(中等高PPO活性)等位变异类型的品种频率分剐为30.4%和69.6%;含Ppo-A1a/Ppo-D1a(较高PPO活性)、PpoAla/PpoD1b(最高PPO活性)、Ppo-A1b/Ppo-D1a(最低PPO活性)、Ppo-A1b/Ppo-D1b(较低PPO活性)等住变异组合类型品种的频率依次为10.1%、37.0%,20.3%和32.6%;不同地区不同等位变异类型及其组合的分布比例也不同.总体来看,陕西低PPO活性的小麦品种比例偏低,选育低PPO活性品种应成为当前陕西小麦品质改良的主要目标之一.     

Research on protoplast preparation and culture in Gladiolus hybridus Hort.

Protoplasts prepared from the aseptic leaves of Rose Supreme in Gladiolus hybridus Hort. were cultured. The yield of protoplasts with vigour was the highest under the following conditions: 1.5% cellulase Onzuka RS, 0.5% pectinase Y-23, 0.6 mol· L~(-1) mannitol, pH 5.8, digestion time 2 h, and temperature 27℃. After isolation and purification, protoplasts were cultured in solid and liquid combined medium, which included KM8P, 0.6 mol· L~(-1) mannitol, 1.0 mg· L~(-1) 2, 4-D, 0.2 mg· L~(-1) NAA and 0.2 mg· L~(-1) KT. The division of the protoplasts first emerged in medium after cultured 4 days, and emerged only a few times.     

Effects of cold stress on hypothalamic corticotrophin-releasing and thyrotropin-releasing hormone messenger RNA levels in chickens

There is increasing evidence that stress can activate the hypothalamic-pituitary-adrenal-axis and hypothalamic-pituitary- thyroid-axis,and further affect the synthesis and secretion of corticotrophin-releasing hormone(CRH)and thyrotropin-releasing hormone(TRH).To evaluate the effect of cold stress on the hypothalamic CRH and TRH messenger RNA(mRNA)levels in Yisha chickens,male Yisha chickens were subjected to acute(1,6,12 h)and chronic(5,10,20 d)cold stress(12±1)℃.Hypothalami were collected for assessment of mRNA levels by semi-quantitative RT-PCR.Acute stress resulted in a significant decrease of CRH mRNA levels at 6 and 12 h,and a significant increase of TRH mRNA levels at every stress time point.Chronic cold stress resulted in a significant increase of CRH mRNA levels and a significant decrease of TRH mRNA levels compared with the control group at every stress time point.The results suggest that the two genes differently respond to cold stress at the mRNA levels.And the different degrees of cold stress will produce different effects on the identical gene.     

马铃薯生理性叶斑病鉴定与诊断方法

为了准确诊断马铃薯生理性叶斑病,对该病害进行了室内鉴定和田间调查。结果表明:马铃薯生理性叶斑病是由于刮风,使叶片间互相摩擦、叶片与地面摩擦、叶片被大风吹翻转后雨滴的直接击打或雨滴溅起的泥沙击打,从而使叶肉组织受到坏死后形成的斑点;该病典型症状为病斑褐色,有时有光泽,圆形或不规则,1~5 mm大小,有时多个病斑愈合;病斑周围无晕圈,无霉层或菌脓菌胶等病征,且病斑多,分布较均匀。     

发展优质专用玉米提高玉米经济伸势

通过分析陕西玉米生产现状和问题,认为提高单产和改善品质是发展玉米生产的两大任务,发展优质专用玉米是调整种植业结构、发展畜牧业和促进玉米深加工的需要;发展优质专用玉米的基本原则是大力发展优质蛋白玉米,积极发展粮饲兼用型玉米,有计划地发展高油和高淀粉玉米,适当发展甜玉米、糯玉米、爆粒等特种玉米.