National Symposium on Strategic Issues in Plant Pathological Research held at Department of Plant Pathology, CSK HP Krishi Vishvavidayalaya, Palampur on November 24–25, 2011
The fungus isolated from foliar blight infected barley leaves was identified as Bipolaris sorokiniana. Eight single spore isolates (I1, - I8) of pathogen were studied for their morphological characteristics like colony growth, colour, sporulation and conidial size. Four isolates (I1, I3, I6 and I7) were relatively fast growing (80.00 to 85.00 mm) as compared to isolates I5 and I8. All isolates were having dirty white colonies with mostly fluffy patterns of growth except I4 and I8, with appressed growth. The sporulation was abundant in isolates I1, I5 and I8 where as it moderate in isolates I2, I3, I6 and I7. The average length of conidia of different isolates varied from 62.00 to 85.25 mm and breadth varied from 25.57 to 27.90 mm with maximum being in isolates I2 and I7. The average number of septa per conidium ranged from 3–8. The shape of conidia was ovate-oblong in all the isolates, however, the colour of candida ranged from deep olive brown (I1, I2, I3, I5, I7 and I8) to light olive brown (I4 & I6). Pathological behaviour of selected isolates (I1, I2, I3 and I4) of Bipolaris sorokiniana on 4 barley (PL 426, PL 419, PL 172, VJM 201) and 3 wheat cultivars showed that all the were pathogenic on barley cultivars but none of the isolates infected wheat and Phalaris minor. Incubation period of different isolates ranged from 4–7 days on barley cultivars. Incubation period was least (4 days) in case of isolate I1 on all the four barley cultivars. The lesions produced were of two types i.e. round and elongated on all the barley cultivars with diameter of 0.56–1.06 mm (round lesion). The length of elongated lesions varied from 2.00 to 3.80 mm and breadth varied from 0.58 to 0.98. Various test isolates also exhibited variation in the disease severity on barley cultivars.
