Vol. 6, Issue 3 (2018)
Physiological inquiry into the acquired thermotolerance of minor millets using Temperature Induction Response (TIR) technique
Author(s): Sowmyapriya S, Partheeban C, R Samundeswari S, and Vijayalakshmi D
Abstract: Minor millets are important staple foods in India. The global rise in temperature has increased the severity of other environmental stresses and markedly reduced the area of minor millet cultivation. Since minor millets are usually grown in marginal lands prone to drought and high temperature there is a need to identify minor millets tolerant to high temperature stresses. To assess temperature stress tolerance, it is necessary to expose the plants to an induction stress before exposing them to the severe stress. Hence an efficient screening protocol referred to as the Temperature Induction Response (TIR) technique has been developed to identify thermo tolerant lines in minor millets viz. Thenai, Kudiraivalli, Varagu, Panivaragu and Samai. Using this standardized TIR protocol, lethal temperature for minor millets was found to be 56оC for 3 hours and the sub – lethal temperature was standardized at 46 to 54oC for 1,2 and 3 hours respectively. Among the minor millets, Samai (CO4) and Thenai (CO6) showed higher levels of intrinsic cell tolerance. Samai CO4 showed highest thermotolerance in terms of high seedling survival (94%) and less reduction in root and shoot growth followed by Thenai CO6. The physiological basis of tolerance revealed that, Samai (CO4) was able to maintain higher chlorophyll stability coupled with higher chlorophyll fluorescence values. It also recorded high photosynthetic rates and stomatal conductances at flowering stage compared to other minor millets under stress conditions. The physiological traits recorded under stress conditions in Thenai (CO6) were also comparable with Samai (CO4). Hence, these genotypes with high level of intrinsic temperature tolerance can be explored as novel donor sources in breeding programmes aimed for developing high temperature stress tolerant minor millets.
Pages: 3633-3638 | 458 Views 69 Downloads
download (6315KB)
How to cite this article:
Sowmyapriya S, Partheeban C, R Samundeswari S,, Vijayalakshmi D. Physiological inquiry into the acquired thermotolerance of minor millets using Temperature Induction Response (TIR) technique. Int J Chem Stud 2018;6(3):3633-3638.
