Selection of Low Chilling Requirements of F1 Pear Hybrid Seedlings
Production of new low chilling requirements genotypes is one of the important objectives in pear breeding program at Department of Fruit Breeding Research to suit warm Egyptian climate conditions. Evaluation of chilling requirement of both pear cultivars parents and seedlings of F1 hybrids were estimated after 200, 300, 400 and 500 chilling hours at 7°C. Cultivars used as parents ('LeConte', 'Hood' and 'Ya Li') were varied in chilling requirement. 'Hood' had the lowest number of chilling hours below 200 chilling hours to bud break, 'LeConte' blew 500 chilling hours while, 'Ya Li' failed to break bud at 500 chilling hours. Seedlings of 26 F1 hybrids 'LeConte' x 'Hood' (LH) and 15 F1 hybrids 'LeConte' x 'Ya Li' (LY) were varied in chilling hours according to its male parent. Using 'Hood' parent reduced chilling hours of LH progenies while 'Ya Li' parent increased chilling hours of LY progenies. Seedlings of F1 hybrids 8LH, 9LH, 10LH, 14LH, 16LH, 17LH, 19LH, 20LH, 24LH, 33LH, 35LH and 44LH were found to be promising progenies as they are low chilling hours.