Retardation of hypocotyl growth by prior heat stress in seedlings of cowpea, melon and tomato

Abstract

SummarySeeds of cowpea, melon, and tomato were planted in moist soil and subjected to a heat stress of 45 °C for 10 h on the day of sowing (day 0), 1 day after sowing or 2 days after sowing. The heat stress subsequently resulted in retarded hypocotyl elongation for all the crops, but the greatest retardation was due to heat stress applied on day 1 for cowpea, day 2 for melon, and day 0 for tomato. The growth-retarding effect of heat stress was associated with a delay, by 1 day, of the maximum rate of elongation of the seedlings.