Identification of Chestnut Blight Agent in Guilan Provinc
2010
Arefipour, Mohammadreza
Chestnut stands are just confined to special areas of Guilan Province including mountainous slopes of Shaft city (Visroud- Taleghan- Lepundan), Talesh city area (Shafaroud- Aghular) and Fooman (Ghaleh roudkhan).These limited areas, which acquire special place for the authorities, in other hand, are subject to virtual decline. The research has been conducted on the base of the written and rigid request of Forests and Range Organization. First, a survey of all infected sites were carried out. Canker and blight symptoms on twigs and trunks were recorded. Branch tips were dried out and trunk bark were erupted in some parts carrying abundant dense orange spots. Collected samples of twigs, trunk and roots of infected trees were examined macro and microscopic. Slides of infected parts were prepared. In order to remove unwanted color pigments out of the plant tissue and softening of the infected host cells, samples were boiled out in 10% KOH solution. In this phase, clear and bright slides prepared and fixed using canada balsam. Close examination of the slides of infected plant tissue revealed many ascocarps in the stroma. Every ascocarp had a tall neck. Perithecia 300-400 micrometer in diameter - embedded in stroma - dark brown to black, membranous, globose to flask shaped with slender black necks up to 600 micrometer long. Asci oblong elliptic to subclavate, 30- 60 X 7-9 micrometer. Ascospores hyaline, two-celled, sometimes constricted at the septum, ellipsoid, 7-11 X 3.5-5 micrometer, with a gelatinous envelope. According to the scientific references, this fungus was identified as Cryphonectria parasitica (Murr.) Barr. This is the first report of the fungus in Iran. In final stage, pathogenicity testing was conducted by artificial inoculation of healthy chestnut seedlings.
显示更多 [+] 显示较少 [-]