COMBINING ABILITY FOR HEAT TOLERANCE TRAITS IN BREAD WHEAT (TRITICUM AESTIVUM L. EM. THELL)

Abstract

Two experiments under normal and late sown conditions consisting of forty five crosses, ten parents and standard check, were conducted at Wheat Research Unit, M.A.U. Parbhani. The results indicated that parents HI 977, PBN 3235 and PBN 1607-2 are good combiners for heat tolerance, while Sonalika for proline content. NI 5439 and CC 464 were good combiner for chlorophyll content and stomatal frequency. Kalyansona had high gca effect for yield per plant under normal and pooled analysis, whereas Parbhani-51 had high gca under late sown conditions. The studies revealed that crosses viz., PBN 3375 x Sonalika and PBN 3963 x PBN 3235 for chlorophyll stability index, MACS 2496 with PBN 3235 and PBN 3324 and Sonalika x PBN 1607-2 for heat injury per cent, PBN 3963 x Kalyansona and HI 977 x PBN 3235 for proline content; had high sca effects for heat tolerant parameters. The crosses Hindi 62 x Ajantha, Hindi 62 x CC 464 and Kalyansona x NI 5439 were found to be heat tolerant. The studies also revealed that parents like OC 464, NI 5439, Parbhani 51, PBN 1607-2, MACS 2496 could be utilized in multiple crossing programme and further biparantal matings for selection of high yielding progenies for heat tolerance.