تأثير فترة الخزن في حيوية الأجسام الحجرية المنتجة من الفطر Sclerotinia sclerotiorum (Lib.)‎ de Bary و الفطريات المرافقة

Abstract EN

Laboratory study was conducted in the Biology Department , Education College for Pure Science from July ,2ooo till February 2009.

The aim of this study was to study the viability of sclerotia which is produced in the lab.

from Sclerotinia sclerotiorum(Lib.)de Bary fungus grown on wheat media for long term study and to make use of it for scientific and experimental purposes completing a previous study dealt with the viability of the sclerotia either for short term study or using natural sclerotia.

Sclerotia were kept in the lab.

atmosphere away from the humidity and the light under a temperature ranged between 42±2oC during summer season and 10± 2o C during winter .

In order to get uniform size of sclerotia , they were classified into two groups ; large sclerotia their diameter equals or more than 2mm and small sclerotia,less than 2mm in diameter .

Results revealed a highly negative correlation between sclerotia viability and the period of storage reaching to 0% with the small sclerotia in the 7 th year and to 10%with the large sclerotia in the 8th year of the storage .

One hundred and ninety six fungal species were isolated from the large sclerotia whereas , 185 species were isolated from the small sclerotia.

Fungi recorded 90% and 100% of a occurrence on the large and small sclerotia respectively .

Trichoderma spp.

recorded a higher occurrence percent (i.e.42-50)% and a higher frequency per cent (i.e.17.9%) on the large sclerotia .

Fusarium spp.

recorded a higher occurrence per cent (36.25%) and a higher frequency per cent(i.e.15.7%)on the small sclerotia.

The total occurrence percent of both sclerotia was associated with Asp.

niger (61.25%) .

The total frequency per cent of both sclerotia appearea with Trichoderma spp.(15.8%).

It could be concluded that accompanied fungi with the sclerotia play an important role of the viability of sclerotia , and the storage's conditions of the lab may increase the chances of sclerotia pollution which is considered a beneficial way from the practical side in the biological control.