Occurrence of red leaf mottle on sugarcane in India.
During 1998-2001, symptoms resembling those of red-leaf mottle disease caused by peanut clump virus were observed on sugarcane cv. CoSe 93232, CoS 767, 96-137, Co 97017 and Co 9916 in Uttar Pradesh and Haryana. Affected plants showed various degrees of mottling (mild to severe), which later turned into red streaks of varying intensities. CoSe 93232 showed white streaks or bands parallel to mid vein which was further converted into red streaks. The symptoms were not associated with marked growth disorders but slight stunting in many diseased plants was observed. Chlorotic lesions were observed on Chenopodium amaranticolor by inoculated infected sugarcane leaf extracts. The leaf dip preparations under electron microscopy revealed the presence of rigid rods averaging 250×20 nm in extracts of mechanically inoculating plants of C. amaranticolor (chlorotic lesions) and Saccharum hybrids (mottling). Sugarcane leaf extracts were highly reactive in DAC-ELISA and western blotting test against polyclonal antiserum of peanut clump virus prepared from sugarcane isolate at CIRAD-CA, Montpellier, France. Hence, the virus was identified as peanut clump virus-sugarcane isolate, the causal agent of red leaf mottle disease and is also the first record of PCV infecting sugarcane in India.