覆膜对宁南山区马铃薯光合特性和产量的影响

以青薯9号原种为材料，采用大田单因素随机区组设计，以不覆膜为对照，研究了覆盖黑膜和白膜对马铃薯光合特性、荧光参数、干物质积累以及产量的影响。结果表明：与不覆膜相比，覆膜条件下马铃薯净光合速率提高0.4~3.0个百分点，气孔导度和胞间CO₂浓度平均增加31.45%和6.58%，Fv/Fm、Fv/Fo、PI分别提高了2.47%、12.18%、20.93%；蒸腾速率在马铃薯生育前期覆膜比不覆膜降低20.82%，而后期却比对照增加8.55%，热耗散量子比率Fo/Fm覆膜较不覆膜处理降低7.11%，差异达显著水平；覆膜比不覆膜处理条件下马铃薯干物质积累量增加0.25~1.86个百分点，大薯率和中薯率分别增加33.78%，15.73%，每公顷产量增加43.08%，其中黑膜处理的各项指标优于白膜，黑膜比白膜和不覆膜增产16.86%、54.20%，差异达显著水平。因此，覆膜处理可以显著提高马铃薯的光合性能、荧光参数和产量，有效缓解干旱等逆境引起的马铃薯的衰老，减轻干旱对马铃薯的危害。在宁南山区，马铃薯采用黑色地膜覆盖栽培技术具有延缓叶片衰老和增加产量的作用。     

辣椒抗番茄斑萎病毒病研究进展及展望

番茄斑萎病毒（Tomato spotted wilt virus，TSWV）自19 世纪发现以来，在全世界各地蔓延，对多种作物造成重大经济损失。本文以辣椒为例，从TSWV 的发生与分布、病害症状检测、传播方式、防治方法、抗TSWV 育种及展望等6 个方面对国内外辣椒TSWV 的研究现状进行综述。     

Phenotypic plasticity of two invasive alien plant species inside a deciduous forest in a strict nature reserve in Italy

ABSTRACT

Invasive alien plant species (IAPs) represent one of the main biological threats to biodiversity worldwide. Information about their phenotypic plasticity are needed to increase awareness about their future invasive potential. A study about phenotypic plasticity in response to contrasting light regimes and its quantification by a plasticity index (PI) of two IAPs (Ailanthus altissima and Robinia pseudoacacia) inside a Strict Nature Reserve was conducted. R. pseudoacacia showed a 70% higher PI, with a strongly greater value at morphological leaf level, associated with a greater ability to survive and grow in forest understory, explaining its greater widespread. Otherwise, A. altissima showed its highest PI at physiological level, which was associated with the ability to colonize and grow in environments with high-light regimes. Based on these results, the conservative management has limited the presence of A. altissima by its lower ability to grow in forest understory. In fact, the small-scale gaps in the forest infrastructure, that could allow its recruitment, are originated only from the death of a single tree or small group of trees. Regarding R. pseudoacacia, it is critical to maintain this type of management because any disturbances resulting in large openings could further promote its presence inside the Reserve.     

刺葡萄棒状拟盘多毛孢叶斑病病原菌的分离鉴定及其防治药剂筛选

葡萄叶斑病是一种严重影响葡萄产量的病害。为了明确引起刺葡萄叶斑病的病原菌种类及筛选有效防治药剂,本研究从福建农林大学实践教学基地采集刺葡萄‘高山二号’10片典型叶斑病病叶片,对分离得到的菌株进行形态学和分子鉴定。结果表明,通过形态学特征结合rDNA-ITS(ITS)、β-tubulin和EF-1α序列分析确定分离到的菌株均为棒状拟盘多毛孢Pestalotiopsis clavispora。防治药剂筛选的结果显示,不同的防治药剂对炭疽病菌的抑制效果不同,60%唑醚·代森联水分散粒剂和25%嘧菌酯悬乳剂对该病原菌菌丝生长的抑制效果最好,其EC_(50)分别为0.119 mg/L和0.178 mg/L;其次为80%波尔多液可湿性粉剂,其EC_(50)为1.766 mg/L;抑制效果最差的药剂为50%多菌灵可湿性粉剂,仅表现出轻微的抑制作用。防治棒状拟盘多毛孢菌丝生长和孢子萌发的最佳药剂是60%唑醚·代森联水分散粒剂和25%嘧菌酯悬乳剂,可作为备选药剂进行田间刺葡萄叶斑病防控试验。     

袋栽黑木耳菌包困菌出耳的技术误区分析

本文针对黑木耳袋料栽培工艺中的困菌出耳技术误区进行了剖析,分析了该误区现状及产生原因,并提出了相应的对策,以期为科学袋栽黑木耳提供参考。     

甜瓜黄斑病毒在海南黄瓜上的发生分布及序列分析

 应用特异性引物MYSV-L-F和MYSV-L-R对海南5个市县采集的150份疑似感染病毒病的黄瓜样品进行RT-PCR检测,在三亚、乐东和东方等3个市县的18份样品中检测到甜瓜黄斑病毒(Melon yellow spot virus, MYSV)。选取采自三亚的分离物C29(MYSV-Hainan)进行MYSV全基因组克隆及序列分析,结果表明:该分离物的L RNA、M RNA和S RNA基因组全长分别为8 918 nt、4 815 nt和3 257 nt,与已知MYSV分离物的核苷酸相似性分别为97.4%~97.7%、96.2%~97.9%和94.8%~99.8%,系统进化关系分析与相似性分析一致,序列相似值越高,系统进化关系越近。     

hrpZ_(Psta)在转基因大豆中定量表达与疫霉根腐病和灰斑病抗性相关研究

以T5转hrpZPsta基因大豆JN29-705-15和JL30-187为材料,利用实时荧光定量PCR技术(Quantitative Real Time PCR,qRT-PCR)检测了目标基因在转基因大豆不同组织中的表达量,分别利用下胚轴侵染法和叶面喷施法鉴定疫霉根腐病抗性和灰斑病抗性,并分析目的基因表达量与疫霉根腐病和灰斑病抗性的相关性。结果表明:hrpZPsta基因在大豆的叶、茎、根、籽粒中均有表达,二个株系平均相对表达量分别为8.2/6.1、0.9/0.7、6.5/4.6和0.8/0.7;T5转hrpZPsta基因大豆抗疫霉根腐病和灰斑病能力与野生型相比均有所提高,JN29-705-15对疫霉根腐病抗性从感病提高到中抗,而JL30-187从中抗提高到抗病;hrpZPsta基因在叶中的表达量也与抗灰斑病能力呈正相关,与病情级别呈极显著负相关。试验结果初步证明了外源基因hrp ZPsta在大豆植株中的表达量与受体植株对疫霉根腐病和灰斑病抗性存在一定的相关性。     

A new Curvularia lunata variety discovered in Huanghuaihai Region in China

The purpose of this study was to identify the dominant pathogens of Curvularia leaf spot and their pathogenicity variation in Huanghuaihai Region of China in recent years. In 2013 and 2016–2017, the occurrences of Curvularia leaf spots on maize were investigated in fields located in Henan, Hebei, Shandong, and Anhui provinces, and 292 fungi were isolated from diseased leaves. These fungal isolates were subjected to morphological identification, and 232 isolates were found to have about 70% uncurved conidia and were identified as Curvularia lunata var. Most of the conidia of 2 representative isolates, namely, HNWB-131 and HNWB-185, were oblong with parallel septations and were distinctly different from a reference isolate CX-3. For further determination, the internal transcribed spacer(ITS), glyceraldehyde 3-phosphate dehydrogenase(GPDH), the large subunit(LSU), and translation elongation factor 1-alpha(EF1-α) sequences of HNWB-131, HNWB-185, and CX-3 were amplified and sequenced. The results of sequence analysis showed that the 4 gene sequences from the 3 isolates had a similarity of more than 99% to C. lunata. Based on the sequences of ITS and the combined data of the 4 genes, neighbor-joining trees were constructed for phylogenetic analysis. The results indicated that these 3 isolates were clustered together with C. lunata. The expression of Clg2 p and ClUrase genes in mycelia and conidia was significantly(P0.05) higher in CX-3 than in HNWB-131 and HNWB-185. This study found that the dominant pathogen of Curvularia leaf spot was a new variety of C. lunata with morphological variations in Huanghuaihai Region from 2013 to 2017. The pathogenicity of the C. lunata var. was not significantly enhanced, and the expression of Clg2 p and ClUrase genes of C. lunata var. was decreased.     

Digestive Enzyme Activity during Larval Development of Black Snook,Centropomus nigrescens

Black snook, Centropomus nigrescens, have been identified as a promising candidate for aquaculture although, like many of the Centropomid species, high mortality associated with early larval stages presents a significant bottleneck to their commercialization. The digestive capacity of black snook larvae throughout the first 37 d after hatch (d.a.h.) was evaluated by quantifying digestive enzyme activities using biochemical techniques. Results showed that black snook larvae have alkaline proteases at hatching, which are known to be important during the first days of feeding for digestion. Toward the end of the study, acid proteases concentration increased (37 d.a.h.). Enzymes for lipid digestion, pancreatic lipase and bile salt‐activated lipase, were already present in the larvae before exogenous feeding commenced, and their activity increased with age and growth (length). Intracellular digestion, measured as the activity of leucine‐alanine peptidase, was high early on (5 d.a.h.) and decreased as development progressed (next 32 d). In contrast, alkaline phosphatase activity was lowest at first feeding and subsequently increased with age. Overall patterns in enzyme activity suggest the possibility of live feed weaning before 32 d.a.h. if artificial diets can be properly balanced.     

红树植物—白骨壤黑斑病病原菌的分离与鉴定

<正>红树林是生长在热带、亚热带海岸潮间带,可海陆两栖的特殊木本植物群落,具有防风御浪、净化环境、维护沿海湿地生物多样性等生态功能,为珍稀植物群落。有报道认为红树植物生长在海边又富含抗菌等活性物质,不利于病害发生,但近年来本实验室在广东雷州半岛等地红树林发现有多种病害发生~([1,2]),仅白骨壤(Avicennia marina)上就发现有黑茎病、灰斑病等病害。2014年我们在该区白骨壤小苗