Abstract
Maize is an important food, feed and industrial crop that is severely affected by adverse climatic conditions, especially heat stress. An experimental study was designed to characterize maize hybrids of different origin for morphological and phenological traits under heat stress. The research material consisted of 21 maize hybrids of different origin. Data were recorded for different plant traits related to heat tolerance: days to 50% tasseling, days to 50% silking, plant height, cob height, plant harvested, cob harvested, cob length, number of grains per cob, thousand grain weight, shelling percentage and grain yield per hectare. The results showed high genetic variability among maize hybrids for yield-related traits under elevated temperature stress. Principal component and biplot analysis were performed to assess heat tolerance in hybrids of different ecological areas. Locally bred maize hybrids FH-988, FH-922, FH-949, YH-1898, YH- 5402 and YH-5133 were found to be the most heat tolerant and possessed high genetic divergence for yield and yield-related morphological and phonological traits under heat stress. The results also showed that days to 50% heading, days to 50% silking, grain yield per plot and cob length could be used as efficient selection criteria for the production of heatresilient maize hybrids.
