不同防控措施对温室番茄品质、产量及发病率的影响

为研究不同防控措施对温室番茄产量、品质及发病率的影响,明确温室番茄优质高产的防控措施,以"瑞粉一号"番茄为试验材料,设置对照(W1)、化学防控对氯苯氧乙酸点花(W2)、生物防控对氯苯氧乙酸点花(W3)、生物防控熊蜂授粉(W4)共4个处理,检测番茄的单果重、维生素C、可滴定酸、可溶性糖、可溶性固形物、糖酸比、固酸比、口感接受度、生理性病害果发生率、晚疫病发病率、灰霉病发病率、叶霉病发病率共12项指标,应用主成分分析法对12项指标进行综合评价。结果表明,12项指标归为2个主成分,代表88.57%的主要品质性状遗传信息量,不同处理的综合得分排名为W4W3W2W1。不同防控措施中W4处理(生物防控措施下熊蜂授粉)综合得分最高,且该处理的植株田间长势好、发病率低。因此,通过生物防控病虫害措施,结合熊蜂授粉,能提高番茄果实产量和品质,减少病害发生,为番茄栽培提供技术指导。     

昆嵛山赤松纯林赤枯病特征及与林分因子的关系

【目的】解析和定量评价林分因子对赤松赤枯病发生(发病率和病情指数)的影响,为昆嵛山赤松纯林的营林措施和赤枯病的预防提供理论指导。【方法】在昆嵛山区域选取林龄相对一致(约34年)的赤松纯林为研究对象,调查林分密度、郁闭度、树高、枝下高、胸径和冠幅6个林分因子及赤枯病的发病率和病情指数,采用方差分析、相关性分析和多重比较分析各项林分因子与赤松赤枯病之间的关系,并通过冗余分析得影响赤枯病发生的关键因子。【结果】赤枯病在赤松林中普遍发生,发病样地占调查样地的96.3%。整体上,高密度林( 2 956 ~4 089株·hm -2 )的发病率和病情指数显著高于低密度林(688~1 822株·hm -2 )和中密度林(1 823~2 955株·hm -2 )的发病率和病情指数;疏林(郁闭度<30%)的发病率和病情指数显著低于中疏林(郁闭度30%~70%)和密林(郁闭度> 70%)的发病率和病情指数;在不同的树高、枝下高、冠幅和胸径分组中,发病率和病情指数均随着分组值的增大而减小。相关性分析表明:林分密度对赤枯病发病率和病情指数的影响均达到极显著正相关水平( r =0.761, P < 0.01;r =0.748, P < 0.01);赤枯病的发病率和病情指数也均受到郁闭度的极显著影响( r =0.509, P < 0.01;r =0.442, P < 0.01);二者与树高均呈极显著正相关( r =-0.443, P < 0.01;r =-0.362, P < 0.01);赤枯病的发病率和病情指数均随枝下高的增大而极显著减小( r =-0.460, P < 0.01;r =-0.419, P < 0.01);二者与胸径均呈负相关关系,且相关性极显著( r =-0.425, P < 0.01;r =-0.373, P < 0.01);随着冠幅的增大,林木发病率和病情指数均极显著降低( r =-0.345, P < 0.01;r =-0.381, P < 0.01)。冗余分析证明林分密度和枝下高对赤枯病发生的贡献最大。【结论】松赤枯病在昆嵛山区域发生较普遍但不严重,其发病率和病情指数在不同林分因子分组中均有差异,且均受各林分因子极显著影响。RDA分析证明,林分密度和枝下高对松赤枯病影响最显著,建议对昆嵛山区域赤松纯林赤枯病的防治工作要以重要因子为主要调控对象,进行合理修剪和间伐。     

基于改进关联方法的河北省农产品加工主导产业选择

为准确把握河北省农产品加工业发展的优劣势,确定应重点扶持的主导产业,该文借鉴中国学者邓聚龙提出的灰色系统理论,对邓氏关联度模型的适用条件进行剖析,提出在研究数据顺序可以调整的行为指标序列关联度问题时,用区间值象代替初值象或均值象,用1和0代替绝对差值最大最小取值的改进思路,以解决因序列始点数据和参照序列变化带来计算结果不唯一以及无量纲化处理可能破坏数据内在关系等问题;从投入产出理论产业关联的本质内涵分析,提出在研究某部门对国民经济的影响力大小时,通过构建虚拟最优前向后向效应参照序列,综合分析其与所有部门的关联效应的优化思路,以更客观真实地反映该部门的拉动推动作用。以2012年河北省139部门投入产出表和2013-2016年农产品加工业统计资料为基础数据来源,采用改进关联度分析方法对17类农产品加工业部门进行综合评价,结果表明:河北省皮毛羽丝加工、棉麻纺织业主营业务收入比例分别位居全省第1、第2位,加权综合优势评价分别位居全省第1、第2位,关联度综合优势评价分别位居全省第2、第1位;中药加工、乳品加工、粮食加工、植物油加工、果蔬加工业加权综合优势评价分别位居全省第4、第5、第6、第7、第8位,关联度综合优势评价分别位居全省第7、第4、第9、第8、第11位,应作为主导产业有针对性地予以重点扶持。研究结果对河北省实施农产品加工业提升行动有参考价值。     

黄瓜与西芹间作土壤细菌多样性及其对黄瓜枯萎病发生的影响

本试验以黄瓜与西芹间作种植模式为处理,黄瓜单作和西芹单作种植模式为对照,利用Illumina公司Miseq平台对上述不同处理土壤进行16S rDNA细菌群落多样性高通量测序分析和田间接种黄瓜枯萎病菌,探讨黄瓜与西芹间作模式土壤细菌的多样性及其对田间黄瓜枯萎病发生的影响。16S rDNA测序结果表明,黄瓜与西芹间作土壤的细菌物种总数最多,群落多样性水平最高,与对照相比显著提高了土壤细菌observed species指数、Shannon指数和Chao1指数(P0.05);Beta多样性聚类分析表明,黄瓜与西芹间作土壤的环境群落物种与黄瓜单作和西芹单作有一定差异性。在门分类水平上,共检测到45个菌门,其中变形菌门占明显优势,其次为酸杆菌门和放线菌门等;黄瓜与西芹间作土壤细菌种类所占比例最高,达98.63%。在属水平上,共检测到428类菌属,GP6、GP16、GP4、芽单胞菌属、节细菌属5属的丰度值较大;黄瓜与西芹间作土壤的节细菌属分布比例最高,红游动菌属、鞘氨醇单胞菌属和芽球菌属丰度值较大,为黄瓜与西芹间作土壤细菌明显优势菌属。田间接种黄瓜枯萎病菌试验结果表明,采用上述3种不同种植模式土壤种植黄瓜,在黄瓜苗期接种黄瓜枯萎病菌,黄瓜与西芹间作处理的黄瓜枯萎病的田间发病率较西芹单作和黄瓜单作分别降低57.03%~63.54%和66.95%~72.15%。因此,黄瓜与西芹间作增加了土壤细菌群落多样性,降低了黄瓜枯萎病的发病率,对后茬黄瓜土传病害防控具有一定科学指导意义。     

Adaptation of the New Zealand Psa risk model for forecasting kiwifruit bacterial canker in Korea

Bacterial canker of kiwifruit, caused by Pseudomonas syringae pv. actinidiae (Psa), is a severe threat to kiwifruit production in Korea. An existing infection risk model from New Zealand was adopted to respond to this epidemic. Disease incidence (proportion of diseased leaves on each vine) and weather (hourly temperature, rainfall and relative humidity) data required to develop the model were collected and analysed in the study. Disease incidence data were used to modify and validate the existing model. Because the Psa risk model was originally developed in a region where the characteristic climatic conditions are completely different from those in Korea, the temperature and rainfall functions of the existing model were modified. Analyses using statistical correlation and prediction–realization tables revealed that the modified model is valid with high agreement (a correlation coefficient of 0.85 and an accuracy of 85.7%, respectively) between the observed disease incidence and simulated disease risk from the model. The model was also found to be more highly sensitive to the presence or absence of rainfall than any other weather variable inputs. Uncertainty in simulated disease risk was measured based on the level of uncertainty in temperature input from weather forecasts. Overall, these results indicate that the modified Psa risk model can be used to provide practical and applicable information for timely disease control to the kiwifruit growers in Korea.     

河北省小麦冠腐病田间发生消长动态监测

为了明确小麦-玉米连作种植模式下小麦冠腐病的发生危害规律及防治时期,采用田间定点、定期调查的方法,对该病害的田间消长动态进行了监测。结果表明,在2015-2016和2016-2017两个小麦生长季中,3个监测点小麦冠腐病的病株率和病情指数随小麦生育期推移呈上升趋势,春季小麦返青以后冠腐病的发生逐渐加重,拔节-灌浆期小麦冠腐病的发生快速增长。年度间小麦冠腐病的发生程度逐年加重,与2014-2015生长季灌浆期、2015-2016年相比,2016-2017年沧县监测点病株率变化不大,病害的病情指数增长1.0;宁晋监测点病株率增长1.8%~12.2%,病情指数增长0.9~4.3;景县监测点病株率增长21.3%~33.6%,病情指数增长13.5~14.6。在各监测点,随着年度间病害发生程度的加重,引起冠腐病的病原菌镰刀菌的分离频率也随之增加。     

甜樱桃病毒病的ELISA检测研究

对陕西省甜樱桃病毒病发生情况进行了ＥＬＩＳＡ检测研究。查明了李属坏死环斑病毒（ＰＮＲＳＶ）、李矮缩病毒（ＰＤＶ）、苹果褪绿叶斑病毒（ＣＬＳＶ）和苹果花叶病毒（ＡｐＭＶ）在甜樱桃上的感染情况,即ＰＮＲＳＶ的感染率最高,ＣＬＳＶ和ＡｐＭＶ的发生也比较普遍,ＰＤＶ的感染率较少。老园的病毒感染率及混合感染类型比幼园高且复杂,说明病毒在樱桃园内可以相互传播。在较老的栽培园中,ＰＮＲＳＶ、ＰＤＶ、ＣＬＳＶ和ＡｐＭＶ的总感染率高达６４．５％。     

金丝小枣浆烂病发病规律研究

通过多年大量室内和田间试验与调查,研究了金丝小枣浆烂病病原菌仁果囊孢壳菌Physalospora obtuse对金丝小枣各器官和枣果的侵染、孢子萌发、越冬寄主、子实体形成规律和侵染率与降水量关系.结果表明,病原菌于6月上旬侵染枣吊、果柄,7月上旬开始侵染枣果,8月下旬为侵染高峰期,9月中旬为田间发病高峰期,前期侵染呈潜伏侵染状态.金丝小枣树皮、枣头、枣股及落果、落叶、落吊均为病原菌越冬场所,其中以落果为主.枣园周围杨树、榆树、刺槐、苹果、梨树、桃树亦为病原菌越冬寄主并传播病原菌造成危害.病原菌在越冬病枣果上可形成有性和无性繁殖体;当年病枣果形成分生孢子发生再侵染.8月中旬、下旬雨量大,是造成金丝小枣浆烂病大发生的关键因子.     

俄罗斯鲟的细胞遗传学分析

实验对人工饲养条件下牙鲆(Paralichthys olivaceus)早期发育阶段摄食节律进行研究。在水温14.4~17.6℃条件下,初孵仔鱼约经5~6d开口摄食,开口饵料为经120目筛网过滤的褶皱臂尾轮虫(Bruchionus plicatilis),17~20d投喂卤虫无节幼体(Artemianauplii),21d后开始投喂桡足类(Copepoda)直至幼鱼阶段。通过对1 090尾仔、稚、幼鱼的测定、统计结果得出:饵料充足时饱食个体占65.8%,日间摄食率达93.7%,10日龄后[全长大于(5.20±0.24)mm],牙鲆日间的摄食率达100%,空胃个体主要出现在10日龄前。仔、稚鱼在早晨8:00和下午16:00出现两个摄食高峰,夜间基本不摄食。幼鱼夜间摄食则比较活跃,摄食量与仔、稚鱼相比明显增加,下午16:00仍为幼鱼摄食高峰。实验结果表明,牙鲆仔、稚、幼鱼具有明显的摄食节律,呈现白天摄食为主,清晨和黄昏双高峰的特点。     

Seed priming with Pseudomonas putida isolated from rhizosphere triggers innate resistance against Fusarium wilt in tomato through pathogenesis-related protein activation and phenylpropanoid pathway

Pathogenesis-related (PR) proteins are one of the major and preliminary proteins accumulated as a defense against biotic stress. This defense response can be induced by using beneficial rhizobacteria, which has been studied in various host-pathogen interactions. In the present study, eleven Pseudomonas isolates were assessed for their potential to ferment sorbitol, reduce nitrate, and produce mycolytic enzymes, 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase, phenazine antibiotics, and N-acyl homoserine lactones (AHLs). All isolates were tested against the host-specific pathogen Fusarium oxysporum MTCC1755 in tomato under greenhouse conditions, and shortlisted isolates were tested for their rhizosphere competence. In-vitro test results showed that the isolates were able to produce mycolytic enzymes, including protease, lipase, chitinase, cellulase, and amylase, and the antibiotic phenazine and were negative for pyoluteorin. All the isolates except two were positive for ACC deaminase production. Greenhouse results showed that the isolates M80, M96, and T109 significantly reduced symptoms of Fusarium wilt. Extended greenhouse tests under autoclaved and unautoclaved soil conditions showed that M80, M96, and T109 were excellent rhizosphere competitors and were identified as Pseudomonas putida. In brief, the defense-specific biochemical variations in the host could describe the improved defense against Fusarium wilt occurring in the primed plants. These three Pseudomonas strains could be used as potential biocontrol agents, along with their rhizosphere competence.