紫胶蚧对寄主适应性的初步研究

紫胶蚧（Ｋｅｒｒｉａｌａｃａ（Ｋｅｒｒ．））是目前最优良的紫胶虫种。该虫的适生区为热带和南亚热带的低海拔地区,最优良寄主是久树（ＳｃｈｌｅｉｃｈｅｒａｏｌｅｏｓａＬｏｕｒ．）。紫胶虫泌胶与寄主的营养成分等有着较密切的关系,国内外都有一定的研究［１～５...     

小麦叶锈菌的特异性分子诊断检测技术

小麦叶锈病由Puccinia triticina引起,是我国小麦生产上的重要病害。本研究旨在建立小麦叶锈菌快速、准确的PCR诊断检测技术体系,用于病害精准测报和综合防控。以真菌β-微管蛋白基因的保守序列为引物,进行小麦锈菌gDNA的PCR比较分析,发现小麦叶锈菌具有长度为268bp的特异性DNA片段;序列分析后设计了2对专化性引物,成功获得检测灵敏度为5.00pg/μL模板DNA浓度水平的小麦叶锈菌种的特异性SCAR标记。对55个来自我国不同麦区的小麦叶锈菌标样以及其它麦类病原真菌的检测表明,该叶锈菌标记的检测可靠性达100%。人工接种条件下,叶锈菌侵染24h后,即可在小麦叶片内检测到该标记。     

Hygroexpansion of wood during moisture adsorption and desorption processes

In order to investigate the shrinking and swelling behavior of wood at a non-equilibrium state, the moisture sorptlon processes of wood under constant and changing conditions were studied. For the static sorption experiment, Chinese fir （Cunninghamia lanceolata） specimens were subjected to the adsorption processes at 25℃, 10 different relative humidity environments and the moisture contents were measured at distinct time intervals of adsorption processes. For the dynamic sorption experiment, the specimens were exposed to periodically and linearly varying relative humidity between 45% and 75% at 25℃. Moisture content as well as radial and tangential dimensional changes in response to the changing relative humidity were measured. The main results from the experiments indicated that： the moisture sorption isotherms of Chinese fir at equilibrium state and different stages of adsorption processes could be characterized by S-shape curves. From the non-equilibrium state to the equilibrium state, the sigmoid moisture sorption isotherms changed from smooth, gradually increasing values to a steep rise at 100% humidity. Furthermore, under dynamic conditions with a constant temperature and a linearly and periodically varying relative humidity, the moisture content as well as radial and tangential dimensional changes of the specimens generally waved but lagged behind the relative humidity change.     

安徽省农业发展主体功能区建设初探

以主体功能区开发的基本理念,浅析安徽农业发展空间布局,指出在守住耕地红线,提高土地利用率和产出率的同时,逐步实现农业产业化和农村城镇化,持续做好扶贫开发,以期共同富裕,全面建设美好乡村。     

氮添加对杨树人工林表层土壤微生物群落结构的影响1）

以江苏东台沿海地区杨树人工林地为研究对象,建立野外模拟氮沉降试验样地,试验设置5个氮处理水平,分别为对照（0 kg· hm－2· a－1）、低氮（50 kg· hm－2· a－1）、中氮（100 kg· hm－2· a－1）、高氮（150 kg· hm－2· a－1）和超高氮（300 kg · hm－2· a－1）。于2012年5月开始在生长季（5—10月）每月进行施氮处理,2013年8月和10月运用磷脂脂肪酸法分别分析了土壤微生物群落的变化特征。结果表明,施氮处理近2 a后,两个月份中的土壤微生物磷脂脂肪酸总量均显著下降,细菌、真菌中磷脂脂肪酸的量出现了不同程度的下降,真菌与细菌中磷脂脂肪酸的量之比没有显著变化。磷脂脂肪酸组成的主成分分析显示,除低氮处理样地外,其他水平施氮样地均使微生物群落结构显著变化,且超高氮处理样地变化格局具有季节差异性。     

海洋高等教育：结构调整与战略发展

为实现我国21世纪海洋发展战略,海洋高等教育结构必须进行战略性调整：层次结构由“橄榄型”向“金字塔型”转变;科类结构由弱势学科向强势学科转变;形式结构由片面型向全面型转变;分布结构走“点一线一面”的发展之路。     

北京地区规模化牛场BVDV持续感染牛清除方案的初步实施

BVDV持续感染牛(persistently infected,PI)是造成牛群内BVD难以根除的重要原因。为摸清北京地区BVDV-PI牛分布情况,探索BVD清除方案,本次筛查利用抗原捕获ELISA,对北京地区7个规模化奶牛场共14028头荷斯坦奶牛进行BVDV抗原检测。共检出PI牛58头,其中成母牛9头,后备牛49头;场内阳性率0.04～1.02%;PI牛与健康牛相比,平均出生体重相差5.9kg(P0.05),15月龄时体重相差94.6kg(P0.05),平均初配月龄和首次怀孕月龄分别延迟2.9个月和4.9个月(P0.05)。结果表明,PI牛个体发育缓慢且繁殖性能低下,但部分牛临床表现正常。以抗原捕获ELISA为主要检测手段的清除方案是控制BVD的有效方法。     

黑龙江省水稻品种对稻瘟病的抗性分析及评价利用

采用室内苗期抗谱鉴定的方法,选取178个稻瘟病菌株对黑龙江省13个主栽品种的抗稻瘟病进行了鉴定。从品种对整个黑龙江省稻瘟病菌株的抗性来看,龙粳14和龙盾104抗性最好,抗谱分别为93．82％和93．26％。从品种对适宜积温带稻瘟病菌株的抗性来看,绥粳7和龙盾104分别是第2和第3积温带抗瘟性最好的品种,抗谱分别为73．08％和95．40％。此外,还利用生物间遗传学关于联合抗病性分析的方法。分析了品种搭配在生产上的应用前景,联合抗病性系数最高的组合是龙稻7和绥粳7,联合毒性系数最低的组合是绥粳4和垦稻10。     

Effect of nitrogen application rate on content of glutenin macropolymer and high molecular weight glutenin subunits in grains of two winter wheat cultivars

Two winter wheat (Triticum aestivum L.) cultivars differing in grain protein content were selected to study the effect of N application rate on changes in contents of glutenin macropolymer (GMP) and high molecular weight glutenin subunits (HMW-GS) during grain filling. Contents of GMP and HMW-GS were much higher in the high GPC cultivar, Xuzhou 26, than those in low GPC cultivar, Ningmai 9. N increased contents of GMP and HMW-GS in Xuzhou 26 with N rate between 0 and 300 kg ha⁻¹, while at the very high N rate of 300 kg ha⁻¹ the contents of GMP and HMW-GS in Ningmai 9 decreased. The high contents of GMP and HMW-GS at maturity were closely related to the rapid increase in contents of GMP and HMW-GS during the initial period of their synthesis. HMW-GS and GMP content were closely correlated. The total HMW-GS content was important in determining GMP content than the content of any HMW-GS pair or any individual HMW-GS present in the selected cultivars. The pattern of response of GMP content to N application rate was closely related to the regulatory effect of N on HMW-GS synthesis.