基于格网的GCM数据修订分析未来海南岛农业水热资源的变化特征

以海南岛为研究区域，选用5个大气环流模式（GCMs）1970−1999年的逐日输出数据和同期地面气象观测数据，使用空间插值降尺度到0.5°×0.5°格网。以格网单元为基础，应用系统误差修订（修正值法或比值法）和多模式集合平均方法（贝叶斯模型平均法BMA或等权重平均法EW），训练与验证GCMs输出值并进行综合修订。在此基础上，分析RCP2.6、RCP4.5和RCP8.5情景下，未来海南岛近期（2020−2059年）和远期（2060−2099年）农业水热资源，包括年平均气温、1月平均气温、≥10℃积温、≥20℃积温、年降水量、1月降水量和≥20℃界限温度生长期间降水量的变化特征。结果表明：GCMs输出值的系统误差和BMA权重系数在格网间存在较大的空间差异，且GCMs输出值低估逐日最高气温约3.55℃，高估逐日最低气温约1.19℃，逐日降水量仅为观测值的54.35%。基于格网的综合修订，可有效降低GCMs输出值在空间上的不确定性，BMA与EW的修订结果相似，均优于单一GCM模式。通过格网BMA综合修订后，最高气温、最低气温和降水量在验证期的相关系数r分别约提升0.10、0.07和0.06；均方根误差RMSE分别约降低2.38℃、1.01℃和1.01mm；较单一GCM相对观测值的偏差平均约减少3.25℃、1.13℃和25.67mm。未来海南岛农业热量资源在空间上主要表现为从中部向外围逐渐升高，高温主要分布在南部至西部沿海地区，年平均气温的增幅全岛较为接近，1月平均气温、≥10℃积温和≥20℃积温的增幅分别表现为由东向西、由北向南和由中部向外围递减。在时间上，RCP8.5情景下所有农业热量资源均为极显著增加且增温最快，RCP4.5情景为先增加后平缓，RCP2.6情景较为平缓，远期无显著增温。未来海南岛降水资源在空间上转为由东向西逐步递减的格局，南部和北部沿海地区降水变率增加，西部和中部降水变率减少，在时间上无显著变化趋势。随着未来海南岛气候变暖和降水格局的改变，农作物适宜种植面积扩大，会对农业生产带来巨大挑战，应提前布局，做好趋利避害。     

微生态制剂对葡萄抗病能力及果实品质的影响

以云南、四川主栽的4个葡萄品种为试材,在常规用药方式基础上辅以微生态制剂,测定其对葡萄酸腐病和黑曲霉病防控效果及对果实品质的影响,以期为有效防控葡萄酸腐病和黑曲霉病的发生,解决生产实践中的具体问题提供科学参考依据。结果表明:微生态制剂能提高葡萄果粒大小和百粒质量,同时增加糖酸比。在传统用药基础上使用绿康威,对葡萄酸腐病和黑曲霉病的防效最佳,分别达52.3%和42.4%;在传统用药基础上使用绿地康3号,其防效为31.3%和21.9%,均表现出良好的防效;前期使用化学药剂,后期单独使用微生态制剂对酸腐病的防效不太明显。     

Identification,characterization and full-length sequence analysis of a novel endornavirus in common sunflower (Helianthus annuus L.)

To identify the possible quarantine viruses in seven common sunflower varieties imported from the United States of America and the Netherlands, we tested total RNAs extracted from the leaf tissues using next-generation sequencing of small RNAs. After analysis of small RNA sequencing data, no any quarantine virus was found, but a double-stranded RNA(dsRNA) molecule showing typical genomic features of endornavirus was detected in two varieties, X3939 and SH1108. Full-length sequence and phylogenetic analysis showed that it is a novel endornavirus, temporarily named as Helianthus annuus alphaendornavirus(HaEV). Its full genome corresponds to a 14 662-bp dsRNA segment, including a 21-nt 5′ untranslated region(UTR), 3' UTR ending with the unique sequence CCCCCCCC and lacking a poly(A) tail. An open reading frame(ORF) that encodes a deduced 4 867 amino acids(aa) polyprotein with three domains: RdRP, Hel and UGT(UDP-glycosyltransferase). HaEV mainly distributed in the cytoplasm but less in the nucleus of leaf cells by fluorescence in situ hybridization(FISH) experiment. This virus has a high seed infection rate in the five varieties, X3907, X3939, A231, SH1108 and SR1320. To our knowledge, this is the first report about the virus of the family Endornaviridae in the common sunflower.     

番茄褪绿病毒在湖南省首次发生

2016年7月在湖南省蔬菜病害调查中发现,4种茄科蔬菜表现出叶脉间褪绿、叶片黄化等症状,疑似被番茄褪绿病毒(Tomato chlorosis virus,To CV)感染,同时叶片背面聚集了大量烟粉虱。采用To CV热激蛋白(heat shock protein 70,HSP70)序列的特异性引物对采集的番茄、茄子、辣椒、马铃薯样品和烟粉虱样品进行RT-PCR检测,均扩增出目标条带,且扩增序列与北京番茄To CV分离物(KC887999.1)部分序列相似度为99.0%,确认采集样品被To CV感染。4种茄科蔬菜To CV的感染率达70%~100%;发病叶片上烟粉虱的带毒率为66.7%~87.5%;鉴定出烟粉虱的生物类型为MED烟粉虱。这是湖南省首次确认该病毒,需要引起关注和加强防范。     

Horizontal transmission and host-virulence attenuation of totivirus in violet root rot fungus Helicobasidium mompa

Monokaryotic strains of Helicobasidium mompa were used as vectors of a mycovirus between various H. mompa isolates to examine the transmissibility of one of the mycoviruses, totivirus (HmTV1–17 virus) in the hypovirulent isolate V17 of H. mompa. The isolates that acquired HmTV1–17 virus were also examined for any alteration in the virulence. Twelve dikaryotic isolates of H. mompa, belonging to 11 mycelial compatibility groups (MCGs) and being mycelially incompatible with isolate V17, were used as recipients of HmTV1–17 virus. Two monokaryotic isolates that were mycelially incompatible with isolate V17 and all of the recipients were also used as vectors of HmTV1-17 virus between isolate V17 and the recipients. When isolate V17 and recipients were directly paired on plate media, HmTV1-17 virus was transmitted from isolate V17 into 2 of the 12 recipients (i.e., 2 of the 11 MCGs). Two monokaryotic strains were paired with isolate V17, and the monokaryotic strains that acquired HmTV1-17 virus were then used as new virus donors. When the monokaryotic strains containing HmTV1-17 virus were paired with the 12 recipients, HmTV1-17 virus was transmitted into 7 of the 12 recipients from the monokaryotic strains (i.e., 7 of 11 MCGs). Based on these results, we concluded that monokaryotic strains could act as vectors to transmit HmTV1-17 virus into H. mompa isolates. When four of the H. mompa isolates that acquired HmTV1-17 virus were used to inoculate apple rootstock Malus prunifolia, the virulence of all of the isolates was attenuated from that of their parental isolates. Moreover, because the DNA fingerprints of the fungal isolates that acquired HmTV1-17 virus were the same as those of their parental isolates, the infection with HmTV1-17 virus is considered the cause of virulence attenuation of H. mompa.     

Growth characteristics of spring barley and selected weeds. II. Effect of temperature and irradiance in growth chambers

As a part of a broader study, two experiments were carried out in growth chambers with three day/night temperature regimes (10/7, 20/14 and 30/21^C) studying growth characteristics of individual seedlings over a four-week period. Experiment 1 was performed with spring barley (Hordeum vulgare L.), Galeopsis tetrahit L., and Viola Arvensis Murray. Experiment 2, with three irradiance levels at 20/14^C, and one irradiance level at the other temperatures, was performed with spring barley, V. arvensis, Chenopodium album L., Brassica rapa L. sspoleifera (DC.) Metzger, and Stellaria media (L.) Vill. Leaf area, dry weight, relative growth rate, net assimilation rate, and net photosynthetic rate generally showed an optimum at 20/14^C. Increasing irradiance resulted in a decreased specific leaf area. Expressed as fraction of shoot dry weight, green leaves decreased and stems, flowers, and yellow leaves increased with increased time, irradiance, and temperature. At all temperatures, barley, B. rapa and G. tetrahit had the largest dry weights, but at 20/14^C. C album and S. media and at 30/21^C C. album also had large values. Differences in dry weight between species correlated more to morphological features than to assimilation rate.     

柑桔溃疡病发病程度对落叶、落果、果实大小及品质的影响

 雪柑叶片、果实溃疡病各病级的落叶率或落果率均随病级的增大而上升;而果实的大小和品质则随病级的增大而下降。除1级的落叶率、落果率、果实大小及品质与0级无显著差异外、其他各级均造成不同程度的大量落叶、落果、和果实变小品质变劣。探明病情指数与落叶、落果、果实大小及品质的关系,并分别建立回归模型。     

Dark lines formed between colonies of isolates of phoma exigua var. foveata on a semi-selective medium

Samenvatting In het Instituut voor Plantenziektenkundig Onderzoek (IPO) te Wageningen wordt gangreen bij aardappel, veroorzaakt door de schimmelPhoma exigua var.foveata, onderscheiden van ander droogrot door aangetast weefsel uit te leggen op een semiselectief medium. Op dit medium wordt de vorming van kristallen van voor de schimmel kenmerkende anthrachinonen bevorderd. De gemakkelijk waar te nemen geelgroene kristallen in het medium wijzen op de aanwezigheid van de betrokken schimmel. Bij een van deze toetsen vormden zich tussen de zich ontwikkelende kolonies van de schimmel donkere lijnen. Deze lijnen verschilden van reeds eerder beschreven violette lijnen, die zich vormen tussen kolonies van de twee variëteitenexigua enfoveata vanP. exigua. Onderzoek aan 27 isolaten vanP. exigua var.foveata toonde aan dat er met betrekking tot de vorming van donkere lijnen 11 verschillende typenP. exigua var.foveata onderscheiden konden worden. Isolaten van deze typen vormden bij gepaarde groei op het selectieve medium donkere lijnen met andere typen, maar niet met isolaten van het zelfde type. Er bleek geen verband met het groeitype van de cultures noch met de vorming van het antibioticum E te bestaan.     

Identification of blackeye cowpea mosaic virus from germplasm of yard-long bean and from soybean,and the relationships between blackeye cowpea mosaic virus and cowpea aphid-borne mosaic virus

Two potyvirus isolates, one from germplasm of yard-long bean (Vigna unguiculata ssp.sesquipedalis) introduced into the Netherlands, and another one from soybean plants (Glycine max) in Indonesia, were compared with two virus isolates of blackeye cowpea mosaic virus (BICMV) from the USA and a Moroccan isolate of cowpea aphid-borne mosaic virus (CAMV). It is proposed that all five isolates be now considered BICMV on the basis of host ranges, symptoms and serology. From our results, and a reassessment of the literature it is suggested to drop the name CAMV in favour of BICMV.Samenvatting Twee potyvirussen, de een in Nederland ingevoerd met genenmateriaal vanVigna unguiculata ssp.sesquipedalis en de ander uit planten van sojaboon (Glycine max) in Indonesië, werden vergeleken met twee isolaten van blackeye cowpea mosiac virus (BICMV) en een Marokkaans isolaat van cowpea aphid-borne mosaic virus (CAMV). Op grond van waardplantenreeksen, symptomen en serologie stellen de auteurs voor om alle vijf isolaten te beschouwen als BICMV. Gebaseerd op de verkregen resultaten en een kritische beschouwing van de literatuur wordt de aanbeveling gedaan om de naam CAMV te laten vallen ten gunste van BICMV.     

Development of a semi-selective medium and an immunofluorescence colony-staining procedure for the detection of Clavibacter michiganensis subsp. sepedonicus in cattle manure slurry

Various compounds and basal media were tested for their suitability to create a semi-selective medium for isolation ofClavibacter michiganensis subsp.sepedonicus (Cms) from cattle manure slurry containing c. 10⁸ colony forming units (cfu) per ml.Plating efficiency of Cms in yeast glucose mineral medium (YGM) was 104% compared with yeast peptone glucose medium. Nalidixic acid, polymyxin B sulphate and the experimental disinfectant S-0208 inhibited colony growth of cattle slurry bacteria as compared with Cms in YGM. The optimal concentration of these inhibitors in combination was determined by modified agar diffusion tests and by pour plating in 24-well tissue culture plates. The semi-selective medium YGMI consisted of YGM supplemented with nalidixic acid (2 mg/l), polymyxin B sulphate (30 mg/l) and S-0208 (125 mg/l). Plating efficiency varied for Cms between 50.9 and 69.6%, for cattle slurry bacteria between 1.8 and 2.5% and for saprophytes from potato heel end extracts between 11.5 and 27.4%.Differentiation of Cms colonies from other colonies was based on their small and bluish colony morphology in pour plates and on immunofluorescence colony-staining (IFC). IFC of a pure culture of micro colonies of Cms in YGM was possible after one day incubation (colonies c. 5 cells). Green background fluorescence in the agar gels was prevented by addition of Tween 20 (0.1%) to the washing buffer and the use of 1% agar gels. IFC of macro colonies of Cms in YGMI, visible with 4x objective magnification, was possible after 4 days. The detection level of the target organism in artificially inoculated cattle slurry in YGMI based on colony morphology varied between 1.4×10³ and 2.3×10⁴ cfu per ml of cattle slurry. Miniaturized plating combined with IFC, using wells in tissue culture plates (=16 mm), proved suitable for detection, but was c. 30 times les sensitive. The recovery of Cms was negatively correlated with the number of saprophytic colonies in the agar plates (R ²=0.74).