长白山区地黄地杂草防除技术研究

地黄对百草枯和扑草净表现出较强的抗药性,百草枯或扑草净分别用600 g a.i./hm2或1 600 g a.i./hm2时,药害等级均低于2级,且药害症状消失较快。扑草净残留测定结果,种植块根的1年生地黄春季土壤处理用40%扑草净2 kg/hm2和4 kg/hm2,秋季收获(施药后152 d)的烘干块根中,扑草净残留量分别为0.042 7mg/kg和0.059 0 mg/kg。     

地黄田节肢动物类群结构及其多样性研究

通过2007年6～11月对陕西省汉中市汉台区地黄田节肢动物群落结构及其多样性进行的调查研究表明,田间节肢动物共73种,分属于2纲,11目,45科。其中以鳞翅目和鞘翅目的丰富度和优势度最高,多样性指数和均匀度以同翅目最高。地黄田天敌数量多,以膜翅目丰富度和多样性最高,以蜘蛛类均匀度和优势度最高。时间动态分析表明,8月份地黄田昆虫数量最多,物种数最丰富,多样性最高。因此,8月是地黄田进行害虫防治的关键时期。     

中国北方番茄主要病毒种类普查及TMV、CMV株系鉴定

1990—1994年,对中国北方15省(市)番茄4种主要病毒种类进行了普查,在3761份样本中,烟草花叶病毒(TMV)和黄瓜花叶病毒(CMV)的检出率分别为34.5％—65.7％和11.6％—62.6％,马铃薯X病毒(PVX)和马铃薯Y病毒(PVY)的检出率一般为10％—20％。与此同时,也对番茄上的TMV和CMV进行了与抗病毒育种紧密相关的株系分化研究,在333个TMV分离物中鉴定出0、1、2和1.2株系,以0和1株系为主,在绝大多数省(市)中分别占分离物的50％和30％以上;在232个CMV分离物中鉴定出轻花叶、重花叶、坏死和黄化株系,以轻花叶和重花叶株系为主,在绝大多数省(市)中分别占分离物的30％和50％以上,这一研究结果为番茄病毒病的综合防治和抗病毒育种提供了科学依据。     

Association of aster yellows subgroup 16SrI-B phytoplasmas with a disease of Rehmannia glutinosa var. purpurea

A new phytoplasma disease of Rehmannia glutinosa var. purpurea was observed in the Czech Republic in 1998. Infected plants showing severely proliferating shoots, leaves reduced in size with vein clearing and chlorosis, shortened internodes and virescent petals died in advanced stages of the disease. Electron microscopy examination of the ultra-thin sections revealed the presence of numerous polymorphic bodies in phloem tissue of leaf midribs and petioles. The disease was successfully transmitted from infected plant via a dodder bridge into periwinkle ( Catharanthus roseus ). The phytoplasma aetiology of this disease was further confirmed by polymerase chain reaction (PCR) using universal primers R16F2/R16R2. Restriction fragment length polymorphism (RFLP) analysis of amplification products indicated the presence of aster yellows related phytoplasmas (16SrI-B) in naturally infected samples of R. glutinosa var . purpurea and in symptomatic periwinkle after dodder transmission of the agent. A comparison of the amplified sequence with 17 sequences available in the GenBank confirmed the classification of the phytoplasma in the subgroup 16SrI-B. This is the first report of natural occurrence of phytoplasma-associated disease in R. glutinosa var. purpurea.     

烟草品种对烟草花叶病毒和黄瓜花叶病毒的抗性鉴定

 2010-2011年采用大田人工接种鉴定的方法,对生产中大面积推广使用的24份烟草品种进行了烟草花叶病毒（TMV）和黄瓜花叶病毒（CMV）的抗性鉴定。结果表明,供试品种对TMV和CMV的抗病性存在较大差异,对TMV表现抗病的有Coker86、吉烟5号、Coker176、CV87、辽烟8号、CV91、中烟90等7份材料;表现中抗的有秦烟98、双抗70、C151等3份材料;表现中感的有秦烟96、G80、金星6007、龙江981、K326、秦烟201、NC89等7份材料;表现感病的有G28、云烟97、净叶黄、红花大金元、RG11、云烟85、云烟87等7份材料。对CMV表现抗病的有Coker86、龙江981、C151、秦烟201、云烟87等5份材料;表现中抗的材料是金星6007;表现中感的有CV91、RG11、Coker176、中烟90、K326、红花大金元、净叶黄、G80、G28等9份材料;表现感病的有秦烟98、云烟85、秦烟96、NC89、双抗70、云烟97、CV87、辽烟8号、吉烟5号等9份材料。其中兼抗TMV和CMV两种病毒病的材料有2份,分别是Coker86和C151。同时研究还发现,抗病性不同的烟草品种在受到病毒危害以后,对烟叶的产量和品质的影响也不同。明确了中国24个烟草品种的抗病性水平,为抗病品种的利用与品种合理布局提供科学依据,同时为烟草抗病毒病育种的亲本选择提供抗源信息。     

五种烟草病毒TMV、CMV、TEV、PVY及TVBMV的多重RT-PCR同步检测

 我国烟草病毒主要有烟草花叶病毒(TMV)、黄瓜花叶病毒(CMV)、烟草蚀纹病毒(TEV)、马铃薯Y病毒(PVY)和烟草脉带花叶病毒(TVBMV),通常发生复合侵染。本研究对我国5种烟草病毒的外壳蛋白基因部分序列设计引物,通过优化引物和模板浓度,摸索扩增参数,在一个体系中成功对5种病毒复合侵染的烟草材料进行多重RT-PCR扩增,得到237、273、347、456和547 bp共5条特异性条带,建立了能同时检测TMV、CMV、TEV、PVY和TVBMV的多重RT-PCR检测体系。对田间样品检测结果证明,多重RT-PCR体系能够同时检测5种病毒,并且灵敏度高。     

侵染西瓜的5种病毒ZYMV、WMV、TMV、SqMV和CMV的多重RT-PCR检测体系的建立与检测应用

 根据5种病毒小西葫芦黄花叶病毒(Zucchini yellow mosaic virus,ZYMV)、西瓜花叶病毒(Watermelon mosaic virus,WMV)、烟草花叶病毒(Tobacco mosaic virus,TMV)、南瓜花叶病毒(Squash mosaic virus,SqMV)和黄瓜花叶病毒(Cucumber mosaic virus,CMV)的核苷酸保守区序列,设计特异性引物对,从影响多重RT-PCR (mRT-PCR)扩增的引物浓度、Mg²⁺浓度、Taq DNA聚合酶浓度、dNTPs浓度、退火温度等方面进行反应体系的优化,建立了一种能够同时检测ZYMV、WMV、TMV、SqMV和CMV的多重RT-PCR技术体系,并进行了实际应用。在一个体系中对上述5种病毒复合侵染的西瓜材料进行多重RT-PCR扩增,得到与试验设计相符的5条特异性条带,依次是542、485、410、354和293bp。该体系实现了对侵染西瓜的5种病毒的同时检测,极大地提高了检测效率,降低了检测成本,体现了多重RT-PCR的优越性。     

Infection experiments of Pyrenophora teres f. maculata on cultivated and wild barley indicate absence of host specificity

European Journal of Plant Pathology - It is important to investigate the possibility of pathogen transmission between cultivated and uncultivated hosts due to the role of the latter in pathogen...     

Seed survival and patterns of seedling emergence studies of Rottboellia cochinchinensis (Lour.) W.D. Clayton in cultivated soils

The longevity of buried Rottboellia cochinchinensis (Lour.) W.D. Clayton seed represents a major survival mechanism for the weed, enabling the persistence of a continuing source of weed seeds in crop land. The pattern of seed persistence and depletion of R. cochinchinensis in cultivated maize soils was investigated by means of (1) studies on the effect of depth and duration of burial on the viability of the weed seeds, (2) quantitative estimation of the seed population and viability in cultivated fields, and (3) the periodicity of emergence and effects of cultivation on seed germination both in the field and in the greenhouse. The results indicated that the mode of persistence was innate (8.5%) and enforced (35%) dormancy after 1 year of burial, and that the persistency component of the seed population on cultivated soils ranged from 40.60%. The weed was able to remain viable at depths of 45 cm, indicating an excellent mechanism of escaping the effects of most soil-applied herbicides, and it was shown that tillage increases the depletion rate of the weed seed reserve by 32% per year.     

Morphological and molecular characterisation of Pratylenchus oleae n. sp. (Nematoda: Pratylenchidae) parasitizing wild and cultivated olives in Spain and Tunisia

A new mono-sexual root-lesion nematode species, Pratylenchus oleae n. sp., parasitizing roots of olive plants cv. Koroneiki in commercial fields at Ouled Chamekh (central Tunisia), and wild and cultivated olive (cv. Picual) plants in Agua Amarga (southern Spain) is described. The new species is characterised by the female having a lip region slightly offset and bearing three annuli, stylet 16.5 (14.5-17.0) μm long, with prominent rounded knobs, pharyngeal overlapping rather long (22–36) μm, lateral fields areolated and with four incisures and diagonal lines in middle band, spermatheca rounded but non-functional, tail short, conoid-rounded to subcylindrical, usually annulated terminus, males unknown, and a specific D2-D3, ITS1, 18S-rRNA, hsp90 and COI sequences. Morphologically this species is related to P. cruciferus, P. delattrei, and P. kumamotoensis. The results of the phylogenetic analysis based on sequences of the D2-D3 expansion regions of 28S, partial 18S and ITS rRNA genes confirmed the close relationship of P. oleae n. sp. with P. dunensis, P. penetrans, P. pinguicaudatus, from which was clearly separated. A PCR-based diagnostic assay was also developed for identification of P. oleae n. sp. using the species-specific primers Poleae_fw1_4 and Poleae_rv1 that amplify a 547-bp fragment in the internal transcribed spacer (ITS1) region of ribosomal DNA, which clearly separate from other root-lesion nematodes damaging olive such as P. penetrans and P. vulnus.