浙江省大豆红冠腐病的病原菌鉴定

大豆红冠腐病(red crown rot of soybean,RCR)是世界范围内的重要的大豆病害之一,病害症状为罹病植株茎基部变红,表面聚集了大量橙红色球状子囊壳。对采自浙江省桐庐县的疑似大豆红冠腐病的病原进行分离和培养,从分离获得的菌株中选择1个代表菌株ZJHZ01进行后续试验和分析,为浙江省大豆产区的红冠腐病的防控提供依据。致病性测定结果表明:菌株ZJHZ01接种大豆茎基部可引起发病,回接症状与田间自然发病症状较为相似。病原菌落初为白色,后变为鹅黄色,菌落中可产生大量红褐色微菌核和厚垣孢子,在PDA、V8和康乃馨叶片培养基中极易产生子囊孢子,与已报道的大豆红冠腐病菌的菌落形态特征相似,初步认为ZJHZ01为冬青丽赤壳(Calonectria ilicicola)。进一步在分子生物学水平上,对其TUB、HIS和EF-1α序列进行PCR扩增和测序,对比Gen Bank中已经录入的丽赤壳属相应序列。基于以上3种基因联合序列,通过采用邻接法构建了的系统发育树。结果表明:菌株ZJHZ01与Gen Bank中C.ilicicola菌株GDBL01存在着极高的同源性,序列相似度达到了99%以上。通过对浙江省桐庐地区大豆产区的大豆病株的病原菌进行致病性、形态学和分子生物学分析,明确了浙江省桐庐大豆产区的红冠腐病是由C.ilicicola侵染所致,这是该病害在浙江省的首次报道。     

圆柏对大气颗粒物的阻滞作用研究

为了研究在单株尺度上林木对大气中不同颗粒物的阻滞作用,选择圆柏作为研究对象,分析3个树冠高度和不同季节中PM_2.5、PM₁₀以及TSP这3种颗粒物的浓度变化规律;对圆柏不同高度上的阻滞效率进行探究,并使用离子色谱对PM_2.5颗粒中的6种水溶性离子成分进行分析。结果表明：不同高度上浓度日变化规律大致相同,浓度差异不大,并均在中午达到最低值;但3个高度的阻滞率差异悬殊,以中部阻滞效果最为明显,尤以PM_2.5为甚,可达47.6%,其次是上部,下部最低;3个季节浓度相差较大,春季最高,夏季次之,秋季最低,且以秋季的波动最为平缓;水溶性离子浓度以Na 、NH₄ 最高,圆柏对F^-、Na 阻滞效果明显,分别为87.62%、68.27%。     

Study on crown profile models for Chinese fir (Cunninghamia lanceolata) in Fujian Province and its visualization simulation

Crown profile models were developed for Chinese fir (Cunninghamia lanceolata) in Shunchang County, Fujian Province. We used data from 360 trees located in 65 pure, even-aged, and unthinned temporary plots. The data were divided into three groups according to site index. Nine models, including models for upper crown, lower crown, and entire crown, were fit; the optimal ones in each group were validated and chosen to estimate crown shape. The optimal models explained at least 70% variability in crown radius (CR). In addition, models for crown width, height above ground to crown base, and height above ground to largest CR were also developed to facilitate the convenient simulation of crown profile models. These three models explained 85.4%, 85.1%, and 86.9% variability. All models also passed the F-test and residual test. The 3D images of a single tree and stands were presented by OpenGL technology on visual c++ platform based on the proposed models. Tree growth was compared and analyzed using crown profile curves under constrained conditions. The analysis results accorded with plant growth.     

“互联网+”引领休闲农业旅游走向新型化

休闲农业是旅游活动的形态之一,具有一般旅游活动的普遍规律。休闲农业在当今社会发展火热,受到政府的大力支持。同时,休闲农业旅游发展逐步面临一些问题,在互联网引领下,休闲农业可以结合“互联网+”,指导休闲农业旅游走向新型化、高效化、智能化,能够有效地满足游客需求,更快捷地认知到休闲农业旅游带给人们的纯真。     

The endophytic fungus Piriformospora indica protects wheat from fusarium crown rot disease in simulated UK autumn conditions

The root endophytic fungus Piriformospora indica (Sebacinacea) forms mutualistic symbioses with a broad range of host plants, increasing their biomass production and resistance to fungal pathogens. This study evaluated the effect of P. indica on fusarium crown rot disease of wheat, under in vitro and glasshouse conditions. Interaction of P. indica and Fusarium isolates under axenic culture conditions indicated no direct antagonistic activity of P. indica against Fusarium isolates. Seedlings of wheat were inoculated with P. indica and pathogenic Fusarium culmorum or F. graminearum and grown in sterilized soil‐free medium or in a non‐sterilized mix of soil and sand. Fusarium alone reduced emergence and led to visible browning and reduced root growth. Roots of seedlings in pots inoculated with both Fusarium isolates and P. indica were free of visible symptoms; seed emergence and root biomass were equivalent to the uninoculated. DNA was quantified by real‐time polymerase chain reaction (qPCR). The ratio of FusariumDNA to wheat DNA rose rapidly in the plants inoculated with Fusarium alone; isolates and species were not significantly different. Piriformospora indica inoculation reduced the ratio of Fusarium to host DNA in the root systems. The reduction increased with time. The ratio of P. indica to wheat DNA initially rose but then declined in root systems without Fusarium. With Fusarium, the ratio rose throughout the experiment. The absolute amount of FusariumDNA in root systems increased in the absence of P. indica but was static in plants co‐inoculated with P. indica.     

Aetiology and toxigenicity of Fusarium graminearum and F. pseudograminearum causing crown rot and head blight in Australia under natural and artificial infection

Globally fusarium head blight (FHB) of wheat is predominantly caused by Fusarium graminearum (FG) and crown rot (FCR) by F. pseudograminearum (FP). While both FG and FP can cause FHB in Australia, the reasons why the morphologically and culturally similar FG is not a major FCR pathogen has remained elusive. Using aetiology and toxigenicity, this study clarifies the contrasting roles of FG and FP in FCR and FHB in Australia. Naturally infected wheat from 42 sites during 2010 FHB epidemics, and wheat inoculated with either pathogen to induce FCR or FHB at three field plantings in 2011, were used to determine pathogen prevalence and deoxynivalenol (DON) content of the crown, stem base, stem top, rachis and grain. As the primary aetiological agent, FP prevalence in the crown correlated with FCR severity while FG in grain and/or the rachis correlated with FHB severity. FG was an effective colonizer of the crown and stem base but colonization was symptomless. DON content was linked to FG biomass in all tissues except the crown, where FP biomass was the main contributor. Of the 30 measures derived to analyse pathogen fitness in 2011, 10 described the superior fitness of FG for FHB; six defined FP fitness for FHB including inoculum dispersal; and eight defined FCR fitness of both FP and FG. FG had superior FHB fitness but weak saprophytic survival may have undermined its FCR fitness.     

基于形态结构特征参数的樟子松人工林单木可视化研究

为更加直观地展示樟子松人工林单木的整个生长过程,将系统分析方法和数学建模技术应用于樟子松人工林单木的形态模拟。通过对樟子松人工林单木形态数据的定量分析,结合前人的研究成果,构建了樟子松人工林单木形态模拟模型,并以VC＋＋6.0为开发平台,利用OpenGL构建了樟子松人工林单木生长模拟系统,整个系统由形态模型模块、树冠结...     

Components of genetic variation for resistance of strawberry to Phytophthora cactorum estimated using segregating seedling populations and their parent genotypes

Strawberry ( Fragaria × ananassa ) seedlings from 50 bi-parental crosses among 20 elite genotypes were evaluated for resistance to Phytophthora cactorum after artificial inoculation. Plots of seedlings or runner plants were rated using a disease severity score and the percentage of stunted plants per plot. The distribution of cross means for percentages of plants with stunting was highly skewed; 79% of the inoculated seedlings showed some level of stunting compared to non-inoculated control seedlings, and all but one of the crosses had 50% or more stunted plants. Disease severity scores for the bi-parental crosses were normally distributed and expressed a range of variation not reflected by the percentage of visibly stunted plants. Factorial analysis based on seedling plot means demonstrated significant additive genetic variance for the disease severity score, and the additive genetic variance was 1·9 times greater than the estimated dominance variance. The cross-mean heritability was     for the severity score. Estimates of the additive genetic variance component using the covariance of severity scores obtained from the seedling analysis and with severity scores for their parents evaluated in a commercial environment were similar,     and 0·30, respectively. Most of the selection response obtained through genotypic selection would thus be transferred to segregating offspring.     

茎基腐亚洲镰孢菌侵染抗感小麦品种的组织病理学观察

小麦茎基腐是由多种镰孢菌侵染的世界性土传病害,亚洲镰孢菌(Fusarium asiaticum)是我国冬小麦主产区茎基腐镰孢菌的优势种群,对小麦生产造成巨大损失。本研究利用绿色荧光蛋白报告基因标记亚洲镰孢菌,研究其侵染抗感小麦的病理组织学过程,建立了茎基腐病菌与寄主互作的直观性的研究体系,对病害防治及抗病育种具有重要意义。基于PEG-CaCl_2介导原生质体转化法将gfp导入亚洲镰孢菌株CF0915,对转化子进行荧光表达、PCR验证、遗传稳定性、生长特性及致病力分析,选取与野生型表现相近的转化子进行侵染分析。结果表明,绿色荧光蛋白基因(gfp)与潮霉素基因(hyg)PCR扩增表明gfp已整合入真菌基因组中,转化子菌丝与分生孢子表现强烈绿色荧光信号,gfp能够在转化子中稳定遗传,菌落形态、生长速度及致病力与野生型菌株无显著差异;将gfp标记病菌分生孢子接种感病品种1 d后,大量孢子附着于根毛及根表皮细胞开始萌发,接种2 d后观察到抗性品种分生孢子萌发;感病品种接种3 d后,菌丝直接侵入表皮细胞或沿表皮细胞间层定殖生长,扩展至皮层组织,8 d后菌丝从根部迅速扩展至茎基部,至第10 d大量菌丝充塞根皮层细胞,叶鞘维管束也被菌丝侵染,并产生大量大型分生孢子,植株表现褐色病斑,14 d后根部及茎维管束被大量菌丝体填充,而后产生大量厚垣孢子,至25 d大部分感病品种幼苗萎蔫死亡;与感病品种相比,抗性品种在整个侵染过程中表现时间滞后。本研究对引起茎基腐病的亚洲镰孢菌侵染小麦的组织学过程观察,为病菌致病机理的阐释及抗病资源的利用提供了重要理论依据。