Isolation and identification of the different pathogens of date palm diseases

Abstract

So far, it is reported from various countries that several fungi are associated with the decline of the growth and production of date palm. Of them, several pathogenic soil-borne fungi, viz., Fusarium oxysporum, F. solani, F. moniliforme, Macrophomina phaseolina; whereas, some fungi like Thielaviopsis paradoxa (Black scorch), Helminthosporium sp., and Alternaria sp. (leaf spots) and Botrydiplodia theobromae (Basal rot) are the predominant pathogen associated with date palm foliar diseases. But, unfortunately the aetiology of date palm decline in India is still unknown. To decipher this complex, date palm infected samples were collected from the field of Date palm Research Station, Mundra, Horticulture instructional Farm, and Agroforestry Research Station of Sardarkrushinagar Dantiwada Agricultural University, Sardarkrushinagar; then subjected to the isolation that yielded colonies of Fusarium sp., Macrophomina phaseolina from the infected root region and Alternaria sp. from infected leaf tissues. Purification and identification of the fungual isolates was done based on in vitro culture characteristics on Potato Dextrose Agar (PDA) and morphology (micro, macro conidia, and chlamydospores, spore shape and size) under the microscope. Based on cultural characteristics pathogenicity and biological performance of the isolated fungus, the causal agent was identified as Fusarium sp., Alternaria sp., and Macrophomina phaseolina were considered to be cause infection on the leaves and roots of date palm seedlings.