Evaluation of Finger millet as heat tolerant crop using physiological and biochemical assays

Under changing climatic conditions, high temperature stress is the most severe problem for the whole agriculture. Identification and utilization of crop plants which can sustain and yield better under high temperature conditions is need of the day. In this study, we established finger millet as thermotolerant crop. For this, we characterized thermotolerant cotton, thermosensitive wheat along with finger millet by MDA accumulation after heat stress and shown that finger millet is even better than cotton. Further, using seed germination test and growing seedlings at higher temperature, it was observed that finger millet was least affected at 42 oC whereas germination percent and fresh weight reduced at 47 oC. With biochemical assay, it was shown that finger millet had very less difference at 42 oC as compared to 37 oC, however there is significant reduction at 47 oC in chlorophyll and carotenoid content and relative water content (RWC) percent whereas increase in electrolyte leakage (%) and H2O2 and O2 concentration. Still finger millet plants can tolerate temperature of 47 oC. Overall, the present study strongly identified finger millet as thermotolerant crop and can be utilized for allele mining of known genes and prospecting of novel genes for crop improvement for high temperature stress.