Ecology, Environment and Conservation Paper

THERMAL INDUCTION RESPONSE (TIR) IN TEMPERATE MAIZE INBRED LINES

Zahoor Ahmed Dar, Madavalam Sreeman Sheshsayee, Ajaz Ahmad Lone, Pratibha Machagondanalli Dharmappa, Jameel Ahmad Khan, Jyoti Biradar, Srikanth, Alie Bashir Ahmad and Jalendra Hagadur Gopal

Abstract

The difficulty of choosing appropriate selection environments has restricted breeding progress for thermo tolerance in highly-variable target environments. Selecting promising lines against thermal stresses on the basis of morphological, molecular and cellular responses has became an fruitful tool in modern day crop improvement programmes. Temperature Induction Response (TIR) technique has been developed and standardized for the rapid assessment of cellular level tolerance in crop plants in order to predict genotype performance under thermal stress of twenty nine maize germplasm lines. Temperature of 50ºC for 3 hrs showed 100% seedling mortality while, the shorter duration of exposure of 1 hr and 2 hr as well as a lower temperature of 48ºC showed some percentage of seedling survival. A significant genotypic variability in the parameters associated with cellular level tolerance (CLT) was observed. Percent seedlings survival ranged from as low as 0% to as high as 100% with a mean survivability of 76.44 %. , while recovery growth ranged from 0 cm to 26.52 cm with a mean recovery growth of 9.12 cm. results therefore clearly indicated the existence of wide and significant genetic variability for CLT in maize germplasm lines. This available variability can be channelized in future breeding programme for isolating promising thermo stable genotypes.