猕猴桃细菌性溃疡病现状及防治方法

介绍了猕猴桃溃疡病的症状及病害循环,综述了猕猴桃细菌性溃疡病原菌的研究进展,并提出了农业措施防治、化学防治、生物防治等措施。     

麻风树无性系种实性状变异与选择

【目的】分析麻风树单果均质量、百粒质量、出仁率、出籽率、种子体积、种仁含油量和单株果实产量等性状的遗传变异,在此基础上,对无性系进行评选.【方法】对海口市新海林场3年生麻风树无性系试验林33个无性系的种实特征进行调查;通过聚类分析,对参试无性系进行分类,并作综合评定.【结果和结论】麻风树无性系间在种实性状上存在显著差异.18号无性系百粒质量最大,26号和20号种仁含油量最高;百粒质量与单果均质量、种子体积和种仁含油量相关性达到极显著水平,种仁含油量除与出籽率和种子体积相关性不显著外,与其他性状相关性均达到显著水平;经综合评价,初步确定1、30、18、15和25号为优良无性系.     

张家口地区绿化植物主要病害种类及其防治

2012～2013年采用踏查法,普查了张家口地区绿化植物的主要病害种类,结果表明,张家口地区绿化植物的病害主要有真菌病害、细菌病害和病毒病害三大类型,其中真菌病害种类较多,以锈病、腐烂病和白粉病为主;并针对这些病害提出了持续有效的防控措施。     

中国桉树真菌病原汇录：2006-2013

本文对2006-2013年期间我国感病桉树或桉树木片上发现的21个真菌物种的分类地位、形态特征、菌落特点、寄主范围、分布地域和危害特点等进行了概述。介绍的对象包括桉树枝干斑点溃疡病原 Teratosphaeria zuluensis（祖鲁畸腔菌）;桉树叶部斑点溃疡病原Teratosphaeria destructans（破畸腔菌）,Mycosphaerella marksii（马克氏球腔菌）,M. crystallina（水晶球腔菌）,M. yunnanensis（云南球腔菌）;桉树顶梢及叶白枯萎病原 Quambalaria pitereka（彼特氏桉座孢）;桉树苗茎腐病原 Calonectria cerciana（桉树丽赤壳）,C. pauciramosa（常丽赤壳）,C. pseudoreteaudii（瑞丽赤壳）;桉树叶焦枯病原 C. crousiana（克儒斯氏丽赤壳）,C. fujianensis（福建丽赤壳）,C. pauciramosa（常丽赤壳）, C. pseudocolhounii（类柯氏丽赤壳）,C. pseudoreteaudii（瑞丽赤壳）;桉树木片腐烂病原Ophiostoma tsotsi（类栎长喙壳菌）;桉树枝干溃疡病原Chrysoporthe deuterocubensis（类古巴黄隐丛赤壳）,Fusicoccum fabicercianum（法比桉树壳梭孢）,Lasiodiplodia theobromae（柯柯豆毛色二孢）,L. pseudotheobromae（类柯柯豆毛色二孢）,Celoporthe guangdongensis（广东暗隐丛赤壳）,C. eucalypti（桉树暗隐丛赤壳）;桉树枝干枯萎病原Ceratocystis acaciivora（相思长喙壳）,C. chinaeucensis（中国桉树长喙壳）。     

内蒙古地区番茄溃疡病菌PCR快速检测技术及22个番茄品种种子表面带菌检测

为快速检测番茄种子表面的带菌情况,以便及时有效防控番茄溃疡病,从而减少病害损失。试验用细菌基因组DNA试剂盒提取番茄溃疡病的总基因组,用通用引物进行PCR反应。以番茄溃疡病菌的DNA为模板,使用专一性引物进行PCR扩增,通过对专一性引物的筛选,最终确定了Cla F1-Cla F2为快速检测番茄溃疡病菌PCR的特异性引物。该检测方法特异性强、灵敏度高,模拟种子带菌,对浸种水的检测灵敏度达1×105CFU/m L。经PCR快速检测,22个番茄品种中只有黑贝番茄、粉红番茄和保罗塔带有番茄溃疡病菌,其余19个品种均未带菌。该方法直接对种子进行检测,不需进行病原菌分离培养,快速简便。     

Screening of Tomato Somaclones for Resistance to Bacterial Canker (Clavibacter michiganensis subsp. michiganensis)

To facilitate testing large numbers of tomato soma-clones for resistance to bacterial canker, a fast screening procedure was developed. Two inoculation methods were investigated, i.e. excision with an infected scalpel of I) one cotyledon of 2-week-old seedlings, and II) the first true leaf of 3-week-old seedlings, followed by applying a drop of inoculum on the wound. Inoculation by method II discriminated well between populations of partially resistant and susceptible tomato genotypes. A criterion for the selection of single, putatively resistant plants, based on rating scores of the severity of wilting symptoms, was proposed and tested with plants of a Lycopersicon peruvianum accession with a relatively high level of resistance to bacterial canker. Progenies of 279 somaclones, derived from tissue explants of the susceptible tomato cultivar ‘Moneymaker’, were evaluated for resistance. The presence of somaclonal variation for morphological characters in these populations was previously shown. However, no differences were detected between the somaclone population and controls in either mean susceptibility or distribution of plants over disease severity categories. Moreover, plants with major increases in resistance were not detected. These results suggest that the potential of somaclonal variation as a source of resistance to bacterial canker may be limited.     

Effect of flooding on the survival of Leptosphaeria spp. in canola stubble

This study used a versatile temperature‐control device to assess the effect of temperature (12–40°C) and duration (2–12 weeks) of flooding on the survival of Leptosphaeria spp. in canola (Brassica napus) stubble. Canola basal stems with blackleg symptoms were submerged in water in small glass jars containing 20 cm³ soil on a thermogradient plate capable of simultaneously maintaining up to 96 independent temperature regimes. Flooded stems were sampled at 2‐week intervals, surface‐sterilized, and incubated on V8‐juice agar for 10 days to recover the pathogen. Flooding for 2 weeks substantially reduced pathogen recovery relative to non‐flooded controls and the pathogen was not recovered after 6 weeks of flooding, irrespective of temperature. The pathogen was eliminated slightly more rapidly at flooding temperatures >20°C than at 12–16°C. There was no difference between Leptosphaeria maculans and L. biglobosa in their ability to survive flooding. Stem tissues degraded most rapidly during the first 2 weeks of flooding, corresponding to a quick decline in pathogen survival during the same period. These results indicate that a paddy rice crop following winter rapeseed may minimize the impact of blackleg by eradicating the inoculum of Leptosphaeria spp. in stubble.     

Effects of plant age on disease development and virulence of Clavibacter michiganensis subsp. michiganensis on tomato

The effect of plant age at the time of inoculation on the severity of bacterial wilt and canker disease caused by Clavibacter michiganensis subsp. michiganensis (Cmm) was examined in six greenhouse experiments. The period during which inoculations led to wilt and death of tomato plants was defined. This period, designated ‘window of vulnerability’, ranged from transplanting to the 17‐ to 18‐leaf stage. Plants inoculated after this period expressed disease symptoms but did not wilt or die. No significant changes in disease incidence were observed when leaves of different ages were inoculated. Yield accumulation was significantly reduced in plants inoculated within the window of vulnerability compared with those inoculated after this period. Expression of virulence genes, viz. celA, encoding a secreted cellulase, and the serine protease‐encoding pat‐1, chpC and ppaA, was induced during the early stages after inoculation in plants inoculated within the window of vulnerability. Differences in Cmm population between plants inoculated within and outside of this period were insignificant after the first week post‐inoculation, indicating that differences in disease severity, yield loss and expression of virulence determinants are not correlated with Cmm population level. Results suggest that implementation of precautionary measures during the window of vulnerability to avoid secondary spread of Cmm will have a season‐long effect on plant mortality and may minimize, or even prevent, yield losses.     

Wound‐healing in cocoa (theobroma cacao l.) stems and its effect on canker caused by phytophthora palmivora (butl.) butler

Investigations on canker development in six cocoa genotypes showed IMC 67 to be resistant, ICS 1, TSH 1188 moderately resistant and TSH 1076, SCA 6 and P 18 as susceptible. Plant wound‐healing components (lignin, callose and suberin) were detected in healthy, wounded and wound‐inoculated (Phytophthora palmivora) tissues of all the genotypes, although at different rates. Lignin concentration was negatively correlated with canker lesion size and positively correlated with time of complete healing. A strong positive correlation was also observed between time of healing and lesion size. The rate of healing of uninoculated wounds was fastest in IMC 67, moderate in ICS 1 and TSH 1188 and slowest in TSH 1076, SCA 6 and P 18 while cessation of lesion expansion was observed at 6 weeks in IMC 67, 8 in ICS 1, TSH 1188 and 10 in TSH 1076, SCA 6 and P 18. This study revealed that lignification plays a role in wound‐healing and consequently a role in resistance of coca stems to P. palmivora infection.     

M13分子标记快速区分树木溃疡病原真菌的种类

树木溃疡病菌具有寄主多样性、危害症状复杂且分布广泛的特点,快速简便地区分真菌类别是杨树溃疡病研究及防治中需要解决的重要问题。在对树木溃疡病菌的遗传多样性研究,发现以M13为引物的PCR扩增可以在不同的种类之间产生稳定分化的带型。因此,本研究分离了43株18种树木溃疡病相关真菌,并且对这些菌株进行rDNA-ITS序列测定及M13-PCR。结果显示,M13带型差异与真菌的特定种类相对应。因此,认为M13分子标记可以准确快速地鉴定、区分树木溃疡病菌。