Screening of Finger Millet (Eleusine coracana L. Gaertn.) Genotypes for Heat Tolerance Using the Temperature Induction Response (TIR)

Abstract

A lab experiment was carried out at the Phenotyping Laboratory, Institute of Frontier Technologies, ANGRAU, Tirupati, to test thirty finger millet (Eleusine coracana L. Gaertn) genotypes collected from the Millet Breeder at ARS Perumallapalle. The aim was to identify which genotypes can tolerate high temperatures by using Thermotolerance Induction Response (TIR) technique. The finger millet seedlings were gradually exposed to increasing temperatures from 37°C to 54°C for five hours, and then to a lethal temperature of 58°C for two and a half hours. After the heat treatment, the seedlings were allowed to recover for two days at 30°C and 60% relative humidity. Among the genotypes after the recovery, their survival percentage, and the reduction in root and shoot growth were measured. Based on these observations, PPR-2773, PPR-1279, PPR-22-1296, and PPR-1211 performed well, showing lower reductions in root and shoot growth, indicating better heat tolerance. This TIR method makes it easier to quickly identify heat-tolerant finger millet lines at the seedling stage itself from a large number of genotypes.