借鉴农机合作社模式探讨内地节水滴灌技术推广应用

文章通过探讨目前在内地开展的农机合作社模式,包括其组建模式、运行管理方式及其作用和优势,提出了在内地推广应用节水滴灌技术的模式,为节水滴灌技术的大面积推广应用提供借鉴。     

基于Translog生产函数的北京市西瓜最优种植规模研究

农业适度规模经营是未来农业的发展方向,本文以规模经济理论为基础,通过建立Translog生产函数模型和DEA包络分析法,最终得出以农户为经营主体的北京市西瓜最优种植规模为6670m2(10亩)。除此之外,研究还发现种植户年龄及文化程度对西瓜种植具有显著影响,但随着农村人口老龄化日趋严峻,培养新型职业农民可以衔接西瓜种植的"断层"。     

1994～2013年渭南建成区的空间扩展研究

基于多期Landsat遥感影像,提取渭南市主城区的建成区数据,结合GIS分析功能,定量分析了渭南建成区的扩展面积和扩展速度,计算了城市重心和扩展方向.结果表明,近年来（1994～2013年）渭南建成区的面积和扩展速度都显著增加,并达到一个相对高的稳定值;随着城市西部高新区的建设,城市重心移动的主基调是由东向西移动,市政府搬迁规划的实施以及各个重大项目的兴建,使其有向北扩展的步态.     

菜豆锈菌侵染过程的显微和超微观察

 本文报道了通过微分干涉衬显微镜、荧光显微镜及扫描电镜和透射电镜所观察到的菜豆锈菌的侵入和扩展过程。菜豆锈菌夏孢子萌发多产生1个芽管,偶尔也产生双芽管。芽管以气孔侵入为主,也可从表皮直接侵入。侵入前形成或不形成明显的附着胞。气孔侵入的芽管首先在气孔腔内形成气孔下囊,再进一步分化出圆形的膨大体,由膨大体产生1~2支初生菌丝。初生菌丝与叶肉细胞壁接触后分化出吸器母细胞,吸器母细胞进入叶肉细胞内部形成吸器。初生侵染菌丝在产生吸器母细胞的部位的后部产生分枝,形成次生侵染菌丝在叶肉细胞间蔓延。     

Dynamic Development of Aphelenchoides besseyi on Rice Plant by Artificial Inoculation in the Greenhouse

A study was done on the relationship between Aphelenchoides besseyi and the symptoms of small grains and erect panicles. This is an important rice disease in Jiangsu Province, China. A. besseyi was extracted from small grains and erect panicles and cultured artificially, and then inoculated into bud and leaf sheaths of seedlings of two Oryza sativa cultivars, namely Zhendao 2 and Wuyunjing 7 in a greenhouse. The effect on rice growth, in particular the small grains and erect panicles, was revealed by the extent of the disease, seed expansion stages, nematode load, and nematode mortality. In contrast to healthy seedlings, the height, length, and the numbers of spikelets of unhealthy panicles of Zhendao 2 were decreased by 6.7, 16.4, and 13.5%, respectively. Before anthesis, nematodes were attracted to the leaf sheath and apical meristem, nematode load increased by 40%; after anthesis, nematodes occurred in spikelets principally and the number increased by 90.8%. The percentages of infected seeds and nematode load were highest in plump seeds and lowest in empty seeds. Nematode mortality on grain with normal endosperm was lower than seeds with abnormal endosperm. Results indicated that A. besseyi was the pathogen in rice with the symptoms of small grains and erect panicles. Wuyunjing 7 manifests only the small grains and erect panicles symptoms and not the symptoms of leaf white-tip. These symptoms of small grains and erect panicles are new symptom records for the disease caused by A. besseyi on rice.     

小城镇用地外延扩张的动力因素探析

处于城市化开发初期，小城镇存在着大中型城市无法获取的优惠的土地使用条件和低廉的土地价格，具有丰富的自然资源、廉价的劳动力资源和广阔的市场等，容易成为企业投资者和经营者的首选地，所以小城镇用地外延扩张十分严重。本文探讨小城镇用地外延扩张动力因素，主要来自于自然、经济、制度、科技、人文与环境等六大因素，旨在引导小城镇用地有序扩展。     

用 1/N 展开法研究钨的能谱

用玻色子1／N展开技术研究了6个钨同位素的能谱和约化电磁跃迁概率B(E2)．结果表明，展开式的高阶项十分重要，6个核的能级能量的理论值和实验值的方均根差，最大的是154keV，最小的只有11keV，符合得令人满意．而且理论能正确地符合实验方面跃迁概率的“回弯”现象．     

农机服务产业化效益分析

随着农村经济的发展和市场竞争的国际化，如何更好地发挥农业机械的作用，进一步提高经济效益，是当前需要探索的重要课题。为此，从农机合理开发利用和增加农民收入的角度出发，调研了山东省各类农机经营形式的现状和效益。其结果有助于提高人们对加快农机服务产业化的认识，从而积极探索新的农业机械经营管理模式和组织体系，推动农业机械化的良性发展和农业生产方式的变革。     

A fine map for maternal lineage analysis by mitochondrial hypervariable region in 12 Chinese goat breeds

As the fast pace of genomic research continues to identify mitochondrial lineages in animals, it has become apparent that many independent studies are needed to support a robust phylogenetic inference. The aim of this study was thus to further characterize the maternal lineage, proposed to originate in southwestern region of China, using a wider survey of diverse goat breeds in China. To this end, we sequenced the mitochondrial hypervariable region 1 (HVR1) of the mtDNA control region in 145 goats of 12 Chinese breeds. Phylogenetic analysis revealed that Chinese goats were classified into four distinct lineages (A, B, C and D) as previously reported. A Mantel test and the analysis of Analysis of Molecular Variance (ANOVA) indicated that there was not an obvious geographic structure among Chinese goat breeds. Population expansion analysis based on mismatch distribution and Fu's Fs statistic indicate that two expansion events in Chinese goats occurred respectively at about 11 and 29 mutational time units ago, revealing two star-like subclades in lineage B corresponding to two population expansion events. Moreover, lineage B sequences were presented only in the breeds of southwestern or surrounding regions of China. Multiple lines of evidence from this study and previous studies indicate that for Chinese goats mtDNA lineage B originated from the southwestern region of China.     

QTL analysis of cooked rice grain elongation, volume expansion, and water absorption using a recombinant inbred population

The traits of elongation, volume expansion, and water absorption are very important in determining the quality of cooked rice grains. In this study, quantitative trait loci (QTL) analysis of these traits was performed using a recombinant inbred population derived from a cross between two indica cultivars, ‘Zhenshan 97’ and ‘Minghui 63 ,’ which are the parents of the most widely grown hybrid rice in China. Using a linkage map based on 221 molecular marker loci covering a total of 1796 cM, a total of 33 QTLs were identified for the nine traits tested. QTLs were detected on chromosomes 1– 3 , 5– 9 , and 11 , respectively. The QTLs identified included three for cooked rice grain length elongation (chromosomes 2 , 6 , and 11), six for width expansion (chromosomes 1‐ 3 , 6 , 9 , and 11) and two for water absorption (chromosomes 2 and 6). Interestingly, a single QTL located near the wx gene on chromosome 6 seemed to influence all the traits tested for the cooked rice quality.