农业科研立题和成果鉴定的情报查新

阐述了农业科研立题,成果鉴定的情报查新的必然性及重要意义,并对查新工作提出了几点建议。     

临夏地区的野生果树种质资源

作者1984—1986年在自治州全境进行调查。基本查明,临夏地区分布有53种野生果树,分别隶属于13科26属。其中木本50种,草本3种;蔷薇科野果最多,有31种,占58.5％。对19种主要野果的糖、酸、维生素C、氨基酸及钙、磷、钾、镁、铁、铜、锌、钼等无机盐和微量元素进行了分析。其中维生素C含量在500mg/100g以上的有8种。特别是西北蔷薇(Rosa davidii Crep),其果实的维生素C含量高达2354 mg/100g,为传统水果的数十至数百倍,远高于沙棘和猕猴桃。此外,并含有人体必需的多种氨基酸和矿物质,是一种高营养野果。它分布广泛,蕴藏量较大,具有很高的开发利用价值。     

Effect of Integration of Fertilizer and Green Manure Nitrogen on Yield Attributes, Nitrogen Uptake and Yield of Lowland Rice (Oryza sativa L.)

Field experiments were conducted at Tamil Nadu Rice Research Institute, Aduthurai, India, during the wet seasons of 1992 and 1993 to study the effect of full and partial substitution of fertiliser N with green manure N (Sesbania rostrata) on nitrogen uptake, yield attributes and yield of rice. The experiment consisted of eight treatments with two levels of N (100 and 200 kg ha⁻¹) and three sources of N application viz., fertilizer, integrated (1:1 fertilizer and green manure N) and green manure N compared to the recommended practice (150 kg fertilizer plus 6.25 t ha⁻¹ (72 kg N) green manure) and a no N control. Nitrogen application markedly increased the N uptake. Combined use of the two N sources at 200 and 222 kg N ha⁻¹ and of single fertilizer N at 200 kg N ha⁻¹ recorded the maximum N uptake, increased the yield attributes such as number of panicles per unit area, weight per panicle, number of total and filled grains per panicle and test weight. At 200 kg N ha⁻¹ full substitution of N by green manure reduced the grain yield but only partial substitution of N by green manure resulted in almost similar yield as single fertilizer N. Thus 200 kg N ha⁻¹ applied in equal proportions of fertilizer and green manure N can be recommended for medium duration rice cultivars.     

标准差在单粒播种机试验中的应用

单粒播种机试验方法中的标准差与众不同,有很多专业特点,研究它利于提高试验水平,进而利于产品质量的提高。为此,探讨了标准差在单粒播种机试验中的应用。     

四川的云南松地径胸径相关关系及其应用研究

本文报道了四川的云南松树干在部三个不同部位直径(地表直径d0．00、0.05m高处直径d0.05、0.1Om高处直径d0.10)与胸径(d1．3)的相关关系，利用其编制了四川云南松地径一元材积表，并对其在四川云南松林区进行盗伐木、滥砍乱伐木材积估计和监测森林资源消耗量等方面的应用进行了探讨。四川云南松地径与胸径最佳关系模型为二次抛物线回归方程，相关系数r=0，999217～0．999380，剩余平方和Q=179．3391～226．4480，且d0.10与d1．3相关关系最为紧密。     

Differences in Wheat Cultivar Response to N Supply. I: Differences in Grain Yield Formation

Two-year field trials with winter wheat cultivars Batis and Toronto were conducted in Southern Bavaria, Germany, to investigate the possible causes of cultivar differences in response to N supply varying in total amount and time of application. Cultivar-related differences in grain yields were observed in treatments with low and medium N supply. High doses of N supply resulted in grain yield adjustment or grain yield advantage for cv. Toronto. The results of this study revealed a consistent, genotypic pattern in response to N fertilization in spite of strong seasonal effects. Systematic modifications in canopy growth rates in response to N supply were of particular relevance and a main factor for differences in tillering intensity resulting in modified stand densities. In the present study, cultivar differences in spike development and interactions with N supply related more to abortion than to initiation processes for number of spikelets and number of flowers per spikelet. High grain density (grains per m²) of cv. Toronto was evident during reproduction stages even under conditions of medium N supply. However, decreased growth rates during the later part of grain filling in combination with low 1000 grain weight, which was barely modified by N fertilization, allowed only partial utilization of this potential. It is assumed that sink limitations were of particular relevance for grain yield development in cv. Toronto, while cv. Batis combined a less intense response to N supply with more stability in the development of grain yield components.     

贮藏中福桔果皮细胞结构的显微观察及果实理化成分测定

贮藏期间福桔果皮细胞始终具有分裂增殖能力,细胞生长的养分主要通过维管束向果肉吸取,因而促进果肉衰老,形成枯水.枯水果实在贮藏早期就发现果皮细胞层和油腔分泌细胞无丝分裂旺盛,双核细胞多,果皮增厚多.严重枯水时,果皮细胞还具细胞核、线粒体、有色体等超微结构,未枯水果实细胞分裂少见.经预贮后贮藏的果实,由于中断了果皮组织与维管束的联系,果皮细胞生长受抑制,果肉水分、养分消耗少,枯水率最低,     

Fractal dimension estimates of a fragmented landscape: sources of variability

Although often seen as a scale-independent measure, we show that the fractal dimension of the forest cover of the Cazaville Region changes with spatial scale. Sources of variability in the estimation of fractal dimensions are multiple. First, the measured phenomenon does not always show the properties of a pure fractal for all scales, but rather exhibits local self-similarity within certain scale ranges. Moreover, some sampling components such as area of sampling unit, the use of a transect in the estimation of the variability of a plane, the location, and the orientation of a transect all affect, to different degrees, the estimation of the fractal dimension. This paper assesses the relative importance of these components in the estimation of the fractal dimension of the spatial distribution of woodlots in a fragmented landscape. Results show that different sources of variability should be considered when comparing fractal dimensions from different studies or regions.     

Detection and characterization of phytoplasmas in diseased stone fruits and pear by PCR-RFLP analysis in Turkey

During the late summer-early autumn of 2002, surveys were carried out in Turkey to determine the presence of phytoplasma diseases in fruit trees. Phytoplasmas were detected and characterized by PCR-RFLP analysis and TEM technique in stone fruit and pear trees in the eastern Mediterranean region of the country. Six out of 24 samples, including almond, apricot, peach, pear and plum, gave positive results in PCR assays. RFLP analysis usingSspI andBsaAI enzymes of PCR products obtained with primer pair f01/r01 enabled identification of the phytoplasmas involved in the diseases. Stone fruit trees, including a local apricot variety (‘Sakıt’) and a pear sample, were found to be infected with European stone fruit yellows (ESFY, 16SrX-B) and pear decline (PD, 16SrX-C) phytoplasmas, respectively. This is the first report in Turkey of PD phytoplasma infecting pear and of ESFY phytoplasma infecting almond, apricot, myrobalan plum and peach; ESFY phytoplasma infecting Japanese plum was previously reported. http://www.phytoparasitica.org posting July 21, 2005.