Traits of significance for temperature variability on cold tolerance of maize inbred lines under field conditions

Abstract

In cool locations like Northern India, for hybrid maize, temperature is the crucial factor in yield and there are relatively few sources of corn that can withstand freezing or cold stress. Under field conditions, the tolerance/resistance of 200 inbred lines to low temperature stress was assessed. The relationship of weather fluctuations was studied on crop growth and cold stress parameters. During the first and second phases of the cold spell (stage I and stage II), inbred plants responded to the cold and frost by starting to yellow and dry their leaves. The findings showed that there was a lot of genetic variation for the tolerance/sensitivitycontrolling characteristics. Sixty inbred lines demonstrated minimal leaf yellowing and healthy plant development in the presence of persistent cold stress. Thirty six inbred lines were found moderately tolerant and the rest of them were susceptible to cold/frost at less than 10°C. Among the resistant source inbred lines, the lines with the higher recovery of more than 50 % for yellowing of leaves as well as plant growth of more than 20 % respectively, among the selected resistant/ tolerant inbred lines include HKI 1352-2 and HKI 1348-6-2 of white maize, HKI 766, HKI 463 and HKI 1160 of normal maize and HKI PC 4B of popcorn. The inbred lines HKI 164-7-6 (0, 23.00), HKI 170 (1+2) (0, 41.02), and HKI PC 11 (0, 34.78) were least affected by the cold stress indicated that did not possess the impact of cold stress even in the adverse or suboptimal temperature as well as showed faster plant growth during growth stage II. Hence, the majority of the resistant inbred lines that displayed low leaf yellowing scores and good plant growth may therefore be used for growing in the winter season and also be employed in the development of cold tolerant hybrids.