Elimination of phytoplasmas in brinjal by meristem-tip culture incombination with thermotherapy

The main aim of the study was to eliminate the phytoplasmas in brinjal using meristem-tip culture in combination with thermotherapy. Brinjal shoot tips were taken from field grown plants and subjected to different temperature/time treatments followed by meristem tip excision and culture in a callus inducing medium. The 45°C for 2 minutes showed the minimum number of days for callus induction and the maximum survival percentage of explants. MS medium with BAP 1 mgl⁻¹ and kinetin 1 mgl⁻¹ recorded the maximum shoot initiation percentage at all temperature treatments. The MS medium with BAP 2 mgl⁻¹, kinetin 1 mgl⁻¹ and NAA 0.5 mgl⁻¹ recorded minimum number of days for multiple shoot formation and produced more shoots per callus clump. For root formation, half concentration in MS medium supplemented with IBA 0.5 mgl⁻¹ and IAA 0.5 mgl⁻¹ recorded lesser number of days for root initiation and produced more roots per shoot. Effective regeneration was recorded at 45°C for 2 minutes. To confirm the elimination of phytoplasmas, DNA was extracted from these plants and from little leaf diseased brinjal plants. The molecular detection was done through PCR and the phytoplasma infected plant sample produced the expected length amplification products while no amplification was observed in the in vitro grown plants.