马铃薯产量与主要产量性状关系的研究

应用灰色系统理论对天水地区8个参试品种产量与产量性状进行综合分析,结果表明,马铃薯产量与主要产量性状的关联度由大到小排序,次序为：单株块茎＞株高＞淀粉含量＞大中薯个数比率＞平均薯重＞大中薯重量比率＞分枝数.该结果对马铃薯育种目标的制定,品种改良具有实际意义.     

Stem and bulb nematode, Ditylenchus dipsaci, associated with a dry rot of potato tubers

About 10% of the ware-sized tubers from a 1990 potato crop were found to have dry rot. The affected tubers had well defined circular patches of dry rot, either with the tuber surface depressed and cracked, or with deep, open cavities where the tuber surface had disintegrated. The rotted tissues contained large numbers of the stem and bulb nematode, Ditylenchus dipsaci. This is the first recorded case in the UK; dry rot of potato tubers is usually caused by the potato tuber nematode D. destructor.     

Characterization of a phytotoxic glycoprotein produced byPhoma eupyrena — A pathogen on water lettuce

Phoma eupyrena, the causal agent of leaf blight disease of water lettuce, when purified by affinity and ion exchange chromatography produced an extracellular glycoprotein (Pe 65) in concentrations of ∼ 8 μg ml⁻¹ in the stationary culture. Coomassie-blue stained SDS-PAGE analysis of culture filtrates and purified Pe 65 showed its molecular mass to be 65 kDa. The blighting and necrosis of leaf tissues were observed within 4–6 days when 1–5 μg of Pe 65 was injected into the mesophyll of water lettuce. These symptoms closely resembled those caused by foliar inoculation with the pathogen. Recognition of Pe 65 by N-glycosidase F treatment and by polyclonal antibodies raised in rabbit against the whole glycoprotein, indicated that the protein is a highly glycosylated protein (50% carbohydrate) and that it is strongly enclosed by the antigenic glycosidic moiety. http://www.phytoparasitica.org posting May 6, 2003.     

一种马铃薯根茎腐烂病病原鉴定

正马铃薯(Solanum tuberosum)为茄科茄属植物,是全世界广泛种植的重要粮食作物~([1])。马铃薯为人们提供了丰富的营养物质,如碳水化合物、多种微量营养素和有利于健康的膳食纤维~([2,3])。马铃薯根茎腐烂病由多种病原菌引起,是马铃薯采后的主要病害~([4])。甘薯长喙壳菌也引起多种植物果实腐烂,如巴西首次报道甘薯长喙壳菌侵染鸡蛋     

河北省甘薯茎腐病研究初报

甘薯茎腐病是近几年在我国发现的一种新的细菌性病害,目前该病已在我国的福建、广东、江西、广西、海南、河南、重庆、江苏等地发生。2013年10月在对河北省甘薯病害的调查中在文安县发现了大量疑似甘薯茎腐病的病株,给当地的甘薯生产造成了严重的影响。经对疑似病株病原菌的分离纯化、柯赫氏法则验证、形态观察以及基于16SrDNA序列的分析,最终确定该病害为甘薯茎腐病,病原菌为达旦提狄克氏菌(Dickeya dadantii)。这是该病害首次在河北省被发现。     

甘薯茎线虫的形态特征

 甘薯茎线虫样本采自河北、山东和安徽省的部分甘薯产区,该线虫种鉴定为腐烂茎线虫(Ditylenchus destructor Thome,1945)。雌虫:线虫唇架骨质化,唇区稍缢缩、有4个唇环和6个唇片;侧区有6条侧线,有网格纹。中食道球梭形、有瓣膜,食道腺通常覆盖于肠的背面达体宽1/2,个别覆盖于肠侧面和腹面;尾呈锥状,稍向腹面弯曲,末端窄圆;卵巢前端卵原细胞双行排列;阴唇略隆起,阴门裂与体轴线垂直,阴门宽度占4个体环;后阴子宫囊大,延伸至阴肛距2/3-3/4。雄虫:虫体前部与雌虫相似。泄殖腔隆起,交合伞起始于交合刺前端水平处向后延伸达尾长3/4;交合刺朝腹向弯曲,前端膨大具指状突;引带短。     

Molecular characterization of Ditylenchus dipsaci on garlic in Turkey

Journal of Plant Diseases and Protection - Garlic plant, which has an important place in the world economy as well as in human nutrition, is grown extensively in Turkey. The stem and bulb nematode,...     

Sweet potato stem blight caused by Alternaria sp.: A new disease in Ethiopia

A new sweet potato disease was discovered in Ethiopia. The disease mainly affects the stems and petioles of sweet potato and the name sweet potato stem blight is proposed. The pathogen is a species ofAlternaria, for which no definite name has been found so far. Sweet potatoes were most susceptible, tomatoes were slightly susceptible, and muskmelons and chilli peppers were resistant. Thorn apples and onions showed slight to moderate symptoms, butAlternaria was not reisolated from these two species. Although all sweet potato varieties tested were susceptible, there were significant differences in sensitivity.     

马铃薯青枯病的PCR检测

以我国11个省(市、区)和6种不同寄主植物的43个青枯菌Ralstonia solanacearum代表性菌株和4个国外青枯菌菌株为试材,采用15条随机引物进行了RAPD分析,筛选到了1条青枯菌所特有的DNA片段,根据其碱基序列,设计了特异PCR引物,对不同青枯菌DNA进行扩增,并以马铃薯的其它病原细菌为对照,只有青枯菌可获得773bp的DNA扩增产物.经过对PCR反应模板制备程序的简化和优化,利用本研究设计的特异引物,直接对马铃薯病块茎的DNA粗提液进行扩增,获得了773bp片段.此技术可望用于马铃薯种薯青枯病菌的检测,大大缩短检测时间,提高检测效率.     

硅酸钠对马铃薯黑痣病的抗性及其抗性相关物质的影响

为明确硅酸钠对马铃薯黑痣病抗性及其抗性相关物质的影响,采用盆栽法在接菌和不接菌情况下施硅酸钠,调查不同处理下马铃薯地下茎和匍匐茎的发病情况,并测定与抗性相关的7种酶活性及木质素含量。结果表明,接菌8 d时,施硅酸钠的马铃薯幼苗地下茎和匍匐茎病情指数分别比不施硅酸钠的降低42.9%和67.2%;接菌12 d时,施硅酸钠的马铃薯幼苗地下茎和匍匐茎病情指数分别比不施硅酸钠的降低55.7%和50.0%。施硅酸钠4~6 d,硅酸钠可诱导马铃薯幼苗体内过氧化物酶（peroxidase,POD）活性升高;不接菌处理时硅酸钠能减缓多酚氧化酶（polyphenol oxidase,PPO）活性降低;硅酸钠对马铃薯幼苗体内苯丙氨酸解氨酶（phenylalanine ammonia-lyase,PAL）活性无影响;不接菌处理14~16 d时硅酸钠能提高马铃薯幼苗体内超氧物歧化酶（superoxide dismutase,SOD）活性,接菌处理时硅酸钠对马铃薯幼苗体内SOD活性无影响;施硅酸钠第10天,马铃薯幼苗体内过氧化氢酶（catalase,CAT）活性升高;施硅酸钠处理第2天,马铃薯幼苗体内几丁质酶和β-1,3-葡聚糖酶活性升高,不接菌处理10~14 d时施硅酸钠降低β-1,3-葡聚糖酶活性;硅酸钠对马铃薯幼苗的木质素含量无影响。     

A Chemo Attractant in Onion Root Exudates Recognized by Ditylenchus dipsaci in Laboratory Bioassay

ABSTRACT A quantitative bioassay that translates preferences of axenically cultured and field population of Ditylenchus dipsaci, observed in vitro, into relative attractiveness of sterile root exudates preparations and their components is described. Onion (Allium cepa cv. White Lisbon) root exudates (ORE) are consistently and significantly much more attractive than the buffer control in all these assays. Exudates from oat cv. Lodi, mustard cv. Albatross and tomato cv. Rehovot 13 are significantly more attractive than the buffer but less attractive than ORE; Arabidopsis sp. cv. Landsberg erecta, oil seed rape cv. Cetes and wheat cv. Bet Hashita are as attractive as the buffer, but canary grass and clover exudates are less attractive than the buffer and, therefore, are classified as repellent. No significant differences in relative attractiveness were detected among exudates from other two cultivars of onion (Texas Grano 502 and Granex Hybrid) and one cultivar of leek (Large American Flag), but exudates from one onion (cv. Evergreen Long White Bunching) and one leek (cv. Broad London) were less attractive than ORE. Relative attractiveness is linear in relation to dilution exponent and therefore log-linear in relation to ORE concentration. Host (onion) penetration study reveals that penetration preferences by D. dipsaci follow the same pattern as those predicted by relative attractiveness coefficients estimated in the bio-assays. Preliminary characterization of the chemo attractant from ORE, using the behavioral bioassay, demonstrated that it was stable to heat and to proteolytic enzymes, nonvolatile and water soluble with a molecular mass <700 kDa.     

马铃薯根系吸收活力与产量相关性研究

在早地田间条件下,通过测定不同品系马铃薯伤流液的多少以反映根系吸收活力的大小,同时测定相应的生物产量和块茎产量。研究表明：在6个供试材料中,1-38品系的根系吸收活力最大,生物产量和块茎产量最高;马铃薯根系吸收活力越大,其相应的生物产量和块茎产量就越高。     

Effects of the springtail Folsomia fimetaria and the nematode Aphelenchus avenae on Rhizoctonia solani stem infection of potato at temperatures of 10 and 15°C

Effects of mycophagous soil mesofauna on Rhizoctonia solani infection of potato stems were investigated in two experiments carried out in growth chambers at 10 and 15°C. The springtail Folsomia fimetaria and the nematode Aphelenchus avenae were selected as organisms suppressive to R. solani . Reduction in Rhizoctonia stem infection by mycophagous soil mesofauna was equally effective at 10 and 15°C. F. fimetaria tended to be more effective than A. avenae , but the best control was obtained when both organisms were present in the soil at high densities.     

Effect of inoculum source on root and tuber infection by potato blemish disease fungi

The incidence of potato pathogens on healthy roots of micropropagated (MP) and seed tuber (ST) plants was examined on successive dates during the growing season in two field experiments. Microplants were grown in a glasshouse for 4–5 weeks in perlite or peal-based substrates, and exposed or not to natural inoculum before planting in the field. The seed tubers originated from stocks of visually clean or moderately blemished tubers and were surface-sterilized or not before planting. Polyscytalum pustulans and Helminthosporium solani only infected roots of ST plants and inoculated MP plants. The incidence of P. pustulans was affected by seed tuber-borne inoculum and, in I year, by the substrate. H. solani was detected infrequently on roots. Rhizoctonia solani was present at low frequencies in most root samples, and more ST than MP plant roots were colonized; there were no substrate effects. In 1 year, increased inoculum levels increased root infection, but only in MP roots. Colletotrichum coccodes occurred at high frequencies and was most common in roots of ST plants. Progeny tubers showed some treatment effects when tested in September and after storage for 6 months, but there were no consistent relationships between root and progeny tuber infection.     

马铃薯受马铃薯甲虫危害后冠层光谱特征的初步研究

使用美国ASD野外便携式光谱仪测量马铃薯受马铃薯甲虫危害后冠层光谱反射率,进行光谱微分、相关分析,得出结论：在750～975 nm范围内,受害后的马铃薯与健康的马铃薯相比冠层光谱反射率下降,红边斜率降低。选择了马铃薯受害后的敏感波段为736～920 nm。     

Population dynamics of the potato cyst nematode,Globodera pallida,in relation to temperature,potato cultivar and nematicide application

The impact of increasing temperatures on the population dynamics of the soil-dwelling nematode Globodera pallida, a persistent and economically important pest of potatoes, was investigated. The reproductive factor (final population⁄initial population) and length of life cycle were found to be temperature sensitive. Pot experiments performed over 4 months allowed comparison of the effect on development of G. pallida of two temperature regimes: an average temperature comparable to current field conditions (14.3 °C) and an average temperature above current field conditions (17.3 °C). A larger second generation of juveniles was observed at 17.3 °C compared to 14.3 °C. Multiplication of G. pallida at field sites in Shropshire and East Lothian (average soil temperatures of 15.5 and 14.1 °C, respectively, during potato cropping) was also examined. A quantitative PCR assay and visual examination of roots were used to monitor the dynamics of the G. pallida populations in both field sites at 4-weekly intervals. Four cultivars, Desirée, Cara, Maris Piper and Estima, were grown with and without nematicide treatments. Nematicide treatments suppressed population increases at both sites. Females were observed on the roots of cvs Cara and Desirée at the end of the growing season in Shropshire, but not at East Lothian, and are likely to represent a second generation.     

A dynamic model of the interactions between the potato crop and Phytophthora infestans1

The onset of Phytophthora infestans attack on potato plants and the further spread of the fungus are largely controlled by the prevailing weather conditions. Mathematical functions have been fitted to numerous experimental results in order to model the effect of meteorological elements on each of the various phases of the fungus' life cycle. By linking the relationships so established in a logical way, a computer sub-model has been constructed which simulates the behaviour of the disease. A potato crop growth sub-model has also been developed, using radiation interception principles. These two sub-models have been merged, forming a joint model which simulates the host/pathogen interaction and provides estimates of both disease progress and crop production under blight attack conditions.     

Direct infection of potato tubers by the root parasite Orobanche aegyptiaca

Parasitic plants of the Orobanchaceae are known as obligate root parasites that develop haustoria that connect to roots of various host plants. This article describes, for the first time, a case where the root parasite successfully connected to potato tubers, i.e. to the swollen portion of an underground stem rather than to a root. The rhizosphere of Orobanche aegyptiaca and of its host Solanum tuberosum (potato) was carefully examined. In anatomical studies, the adventitious roots were directly connected to potato tubers. Numerous secondary haustoria, which developed along the adventitious roots in close vicinity to the potato tuber, penetrated the tuber epidermis and the perimedullary tuber parenchyma and developed xylem strands that are presumably connected to the minor xylem strands within the tuber cortex. These findings indicate that parasites of the Orobanchaceae that normally attack host roots may also parasitise underground stem tubers.