Identification of two new Alternaria isolates on sugar beet (Beta vulgaris L.) plants in Lucknow, India

Abstract

Two hitherto Alternaria species, viz., A. ashwinii and A. dilkushana causing leaf spot on the margins of flavescent and older leaves of sugar beet (Beta vulgaris L.) are being reported for the first time from sub-tropical India. The new strain of fungi was isolated and morpho-taxonomic characters were studied in depth and compared to previous reported Alternaria strains on sugar beet crop in local cultivated field. The comparative analysis revealed variations within different fungal identification traits, viz., symptomatology, hyphae, conidiophore and conidial characteristics that differentiate from previous reported Alternaria strains on sugar beet crop in local area. The new taxon has been proposed as A. ashwinii Mall, Misra, Kumar and Pathak sp. nov. (MB 827099) and A. dilkushana Mall, Misra, Kumar and Pathak sp. nov. (MB 827096). This study will help in giving new direction to molecular diagnostics of these strains. The study also opens up path for future work on its ITS region (referred to as official DNA barcoding), in identifying the various protein coding genes used for boosting or replacing ITS region in species identification of fungi. Highlights Diseases are foremost restraint in attaining high sucrose content and yield in Sugar beet. Amongst the various diseases of Sugar beet, foliar diseases are the most common ones. Foliar diseases are often ignored though they cause substantial losses to yield and sucrose content. Identified two new fungal strains of Alternaria in sugar beet in sub-tropical India.