Evaluation of Foxtail Millet Varieties for Thermotolerance at Seedling Stage using Temperature Induction Response Technique (TIR)

Abstract

In the present scenario of climate change, Foxtail millet is the best crop of choice and an indispensable component of dryland farming due to its C4 plant type and tolerance against the abiotic stresses. However, all the foxtail millet varieties may not sustain under severe temperature stress particularly at germination and seedling growth stages. Therefore, screening of varieties is required to identify the stress tolerant varieties in foxtail millet which can combat temperature stress at seed germination and early seedling growth stages which is the need of the hour under ever changing climatic conditions. Hence, A lab experiment was conducted to standardize the temperature induction response (TIR) protocol for foxtail millet seedlings using WGC-450 programmable plant growth chamber. Temperatures were standardized as sub lethal i.e. challenging temperatures as 38°C – 54°C for 5 hours and lethal temperatures as 56°C for 3 hours. Seven foxtail millet varieties (Suryanandi, SiA 3156, Srilakshmi, SiA 3085, Narasimharaya, Krishnadevaraya and Prasad) were screened for intrinsic tolerance using the standardized Thermo Induced Response (TIR) protocol. Out of the seven varieties evaluated, SiA 3085, Prasad, Suryanandi, Srilakshmi were identified to possess high level of thermo tolerance in terms of higher seedling survival with less reduction in root and shoot growth. The varieties with intrinsic heat tolerance can be explored for the development of heat stress tolerant varieties.