Screening of American cotton (Gossypium hirsutum) genotypes against cotton leaf curl associated begomoviruses

Cotton leaf curl associated begomoviruses (CABs) are emerging as a major threat to the cotton production globally which may reduce the seed cotton yield upto 80 per cent. Screening of available genotypes against cotton leaf curl disease (CLCuD) is a pre-requisite for tackling with this threat. In our studies, 18 genotypes of American cotton were screened at three different locations viz. PAU Regional Research Station, Bathinda, Dr J. C. Bakhashi Regional Research Station, Abohar and at village Bakainwala (District Fazilka) during Kharif season of 2019–20 under natural unprotected conditions. A susceptible check (variety F 846) was sown after two entries as an infector row. All genotypes showed differential disease reaction at different locations. Per cent disease index (PDI) varied from 18.51 to 51.85 and 16.66 to 42.59 at RRS, Bathinda and Dr J. C. Bakhshi RRS, Abohar, respectively while maximum PDI (62.03 to 93.51) was recorded at village Bakainwala. As per mean PDI (Average mean of the PDI of CLCuD of the 3 location), none of the screened genotypes was found be resistant or immune against CLCuD. However, at one location at RRS, Bathinda one genotype (PBH 101) found to be resistant and three genotypes (PBH 105, PBH 106, BH113) were found to be moderately resistant to CLCuD disease. In the location, Dr J.C. Bakhshi RRS, Abohar three genotypes (PBH 105, PBH 113, PBH 118) found to be resistant and seven genotypes (PBH 104, PBH 108, PBH 110, PBH 114, PBH 117, PBH 119, PBH 120) were found to be moderately resistant to CLCuD disease. All the 18 genotypes have shown the highly susceptible reaction to CLCuD in cotton at village Bakainwala.