Abstract
Aim:
To record the prevalence, detection, molecular and biological
characterization of phytoplasma associated with brinjal little leaf disease
in Assam and its management.
Methodology: Roving survey was conducted during the 2018-2020
brinjal growing seasons to record the disease incidence and symptoms
associated with the disease. Insect and dodder transmission studies were
carried out along with tetracycline tests. Further, molecular detection of
all the samples collected during the survey and after dodder and insect
transmission studies were done through PCR assays by using universal primers.
Results:
The disease incidence varied from 3.62 to 23.63 per cent in surveyed
districts. Transmission studies revealed that Hishimonus phycitis
(Dist.) is acting as a vector of brinjal little leaf phytoplasma and found to
be transmitted by dodder (Cuscuta campestris). The phylogenetic
analysis indicated that the Brinjal little leaf phytoplasma understudy was
associated with ‘Candidatus phytoplasma trifolii’ and plants like Datura
stramonium play a major role as potential alternate host of the
phytoplasma. Further, studies on the effect of the antibiotic tetracycline
hydrochloride in managing the disease elucidated that the antibiotic was
effective only for temporary remission of symptoms.
Interpretation: This study reveals a broad picture about
the incidence, phytoplasma associated with the disease, putative leafhopper
vector transmitting the phytoplasma in the field, alternate host harbouring
the phytoplasma, and effect of antibiotic on the disease suppression, which
will be useful to develop effective management strategies.
Key words: Antibiotic, Brinjal little leaf disease, Hishimonus
phycitis, Little leaf, Phytoplasma
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