Abstract
Symptoms typical of phytoplasma infection such as phyllody, virescence, witches’ broom and yellowing were observed in 12 varieties of Chrysanthemum morifolium in floral nurseries and experimental fields at New Delhi, Karnataka, Maharashtra and Andhra Pradesh, India, during surveys made from 2015 to 2017. Disease incidence ranged from 15 to 30%. Phytoplasma presence was confirmed in all symptomatic chrysanthemum varieties by molecular identification assays. Sequence comparison, phylogenetic and in silico RFLP analyses of 16S rDNA sequences allowed the identification of the chrysanthemum infecting phytoplasma strains into different ribosomal groups and subgroups, namely 16SrI, 16SrII-D, 16SrVI-D and 16SrXIV. Detection of phytoplasma strains of 16SrII-D subgroup were also confirmed in symptomatic Chenopodium album and Parthenium hysterophorus plants grown in and around the surveyed chrysanthemum fields at New Delhi, whereas 16SrVI-D phytoplasma strains were detected in symptomatic Cannabis sativa weed and leafhopper Hishimonus phycitis individuals collected from the symptomatic chrysanthemum fields at New Delhi. This is the first report on the presence of 16SrVI and 16SrXIV groups of phytoplasmas in chrysanthemum plants. Studies on genetic diversity of phytoplasmas infecting the major chrysanthemum varieties in India and their epidemiological aspects had previously not been reported. The detection and identification of phytoplasmas in different chrysanthemum varieties could contribute to increase the awareness among farmers in the management of these diseases.
Highlights
Chrysanthemum (Chrysanthemum morifolium Ramat) occupies 3rd and 5th positions in the cut flower and pot plant trades; respectively (Anonymous 2015)
The disease incidence on different chrysanthemum varieties were recorded from 15% in Indira variety at Kadiam, Rajahmundry, Andhra Pradesh to 30% in Pusa Anmol variety at IARI, New Delhi (Table 1)
Chrysanthemum yellows phytoplasma (16SrI-B subgroup) associated with witches’ broom, vein clearing, dwarf and abnormal production of secondary shoots was reported in C. carinatum and C. morifolium from European and Mediterranean areas (Bertaccini et al 1990; Conti et al 1988; Saracco et al 2005)
Summary
Chrysanthemum (Chrysanthemum morifolium Ramat) occupies 3rd and 5th positions in the cut flower and pot plant trades; respectively (Anonymous 2015). It is used as cut flower and loose flower due to its attractive form and colour of flower. In India, it is grown commercially on a large area of 16.63 thousand ha with a production of 186.06 thousand MT (Anonymous 2014). Chrysanthemum has been grown at a commercial scale in different states of India, very little is known about
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
