Molecular identification of 16SrXI-B subgroup of phytoplasma related strain with yellow leaf disease of sugarcane (Saccharum officinarum) in India

In India, yellow leaf disease (YLD) is known to be caused by Sugarcane yellow leaf virus (SCYLV) and Sugarcane yellows phytoplasma (SCYP; 16SrI-B). Therefore, present study was conducted to confirm the association of specific phytoplasma with YLD in Co 0238 and CoS 510 sugarcane genotypes during 2019-2020 at Indian Institute of Sugarcane Research, Lucknow. The YLD affected genotypes were characterized by yellowing of leaf mid-ribs and leaf-lamina, leaf-tip necrosis, bunching of leaves at crown region and drying of plants with an incidence ranged from 28.26-35.81%. YLD symptomatic leaf samples were collected from the two genotypes and subjected to genomic DNA extraction by DNeasy Plant Mini Kit followed by nested PCR assay using universal phytoplasma primers (16S rDNA region). The nested PCR assays of samples from both the genotypes showed specific amplification. 16S rRNA gene sequence analyses of CoS 510 isolate (MN913611) revealed 100% identity with Sugarcane white leaf phytoplasma (SCWLP) belongs to 16SrXI-B subgroup. Similarly, virtual RFLP analyses revealed 1.00 similarity coefficient with 16SrXI-B subgroup. Thus, present study first time reports the association of SCWLP related strain with YLD of sugarcane in India. Phytoplasma infecting sugarcane are more diverse and needs systematic studies on their single or mixed infections in different varieties in India.