| Abstract: | Seed germination and seedling emergence are particularly sensitiveto low temperatures in oil-seed genera in which lipids are themain seed storage material, e g cotton, corn, cucumber, andwatermelon Growth of photosynthetic seedlings of oil-seed generais also significantly affected by suboptimal temperatures. Aphotosynthetic seedling growth system used to demonstrate suboptimaltemperature stress effects in cotton was modified to monitorthe effects of temperatures from 10 to 35 ? upon the roots andaerial portions of cucumber, cantaloupe, and watermelon seedlings.Non-destructive measurements of fresh weights and the relativewater contents of the roots and shoots of seedlings grown at30 ? and at non-optimal temperatures, as well as chilled seedlingsreturned to 30 ? for one day, indicated significant intra-genencdifferences in temperature sensitivity and relative root andshoot water status of both the chilled seedlings and those recoveringfrom thermal stress The capacity to return to normal water statusand resume growth differed between and within species and wascorrelated with recommendations for chilling tolerance Key words: Temperature, water stress, photosynthetic seedling |
