Csinos A S
Department of Plant Pathology, University of Geo, Coastal Plain Experiment Station, Tifton.
Plant Dis. 2005 Mar;89(3):332-337. doi: 10.1094/PD-89-0332.
Flue-cured tobacco cultivars were evaluated for their reaction to race 0 and race 1 of Phytophthora parasitica var. nicotianae, the incitant of the disease tobacco black shank. Seventeen commercial tobacco cultivars having resistance derived from Fla 301 or a combination of Fla 301 and Fla 105 were subjected to root or stem inoculation by 22 different isolates of P. parasitic var. nicotianae collected from across the Georgia tobacco-growing belt. An adapted stem inoculation technique using field-grown tobacco indicator cvs. K-326, NC-71, Coker 371 Gold, and the breeding line NC-1071 was used to determine races of P. parasitica var. nicotianae. Typically, in greenhouse evaluations, cultivars stem inoculated with race 1 of P. parasitica var. nicotianae were killed. Cultivars that had resistance from both Fla 301 and Fla 105 (Ph gene) were not killed, with few exceptions, when inoculated with race 0. Fifty-seven tobacco specimens having black shank symptoms from the Georgia and Florida tobacco belt were evaluated for P. parasitica var. nicotianae race using the adapted stem inoculation technique. Of the samples evaluated from commercial tobacco fields, 83% yielded race 1 compared with a similar evaluation made in 1994, where only 16% of the samples yielded race 1. The increase in race 1 incidence may be related to the increase in use of cultivars which have the Ph gene for resistance. The use of rotations and metalaxyl or mefenoxam may be required where race 1 is found.
对烤烟品种进行了评估，以确定它们对寄生疫霉烟草变种（烟草黑胫病的病原菌）0号小种和1号小种的反应。17个具有来自Fla 301的抗性或Fla 301与Fla 105组合抗性的商业烟草品种，通过从佐治亚州烟草种植带各地收集的22种不同的寄生疫霉烟草变种分离株进行根部或茎部接种。采用一种改良的茎部接种技术，使用田间种植的烟草指示品种K-326、NC-71、Coker 371 Gold和育种系NC-1071来确定寄生疫霉烟草变种的小种。通常，在温室评估中，用寄生疫霉烟草变种1号小种进行茎部接种的品种会死亡。具有来自Fla 301和Fla 105（Ph基因）抗性的品种在接种0号小种时，除少数例外，不会死亡。使用改良的茎部接种技术，对来自佐治亚州和佛罗里达州烟草种植带的57个有黑胫病症状的烟草样本进行了寄生疫霉烟草变种小种评估。在从商业烟草田评估的样本中，83%产生了1号小种，而在1994年进行的类似评估中，只有16%的样本产生1号小种。1号小种发生率的增加可能与具有Ph抗性基因的品种使用增加有关。在发现1号小种的地方，可能需要采用轮作以及使用甲霜灵或精甲霜灵。
