Abstract

STUDIES ON PREVALENCE AND IDENTIFICATION OF NEW RACES OF FUSARIUM MONILIFORME SHELDON INCITANT OF POKKAH BOENG DISEASE FROM UTTAR PRADESH

D.D.K.Sharma, Y.P. Bharti, P. K.Singh, D.N.Shukla & A. Kumar

Field survey conducted during 2011-12 revealed 1.4-30 per cent incidences recorded in six sugarcane varieties viz. CoS8432, CoS8436, CoS98259, CoLk8102, CoJ64 and CoSe01424 of pokkah boeng disease. The characteristics of these varieties observed that juice quality was, dark and dusty, while sugar purity and ccs percent were found lesser followed by healthy canes. These varieties were made into twenty four isolates and pure cultures were maintained upto 12 days on different solid and liquid media in which PDA medium followed by Richard’s medium was best suited for the growth of all isolates at 280C temperature. On the 12 day of incubation, the dry weight of the mycelial mat was recorded in the lower concentration of IBA followed by IAA proved stimulatory to the growth of selected isolates, while higher concentration produced adverse effect on the growth of all the isolates. Out of 24 isolates of Fusarium moniliforme only 10 isolates were found pathogenic. On the basis of physiological characters in which 6 isolates exhibited maximum radial growth (70 mm diam) in 8 days, while the same isolates attained maximum radial growth (80 mm diam) in 10 days. Hence, these isolates (Fm111, Fm114, Fm118, Fm1112, Fm1116 and Fm1120) took 12 days to attain (90 mm diam) growth and rest isolates unable and variable radial growth were found same period. On the basis of morphological and pathological characters these were categorized into six groups and pathotypes. On comparison with known pathogens and isolates were tested on 8 pathological differentials of sugarcane their reaction of Fusarium moniliforme. Out of 5 pathotypes, 3 and 5 were found similar to races 1(Gorakhpur), 4 with race 3 (Lakhimpur Kheri), 6 with race 2 (Meerut) and 2 with race 6 (Florida) but pathotype 1 was found all together different from all races. Hence, it was concluded that these two isolates belonging to new races are first time reported from Uttar Pradesh.