Poster Session 46—Temperature Stress Physiology 21 July 2005, 12:00–12:45 p.m. Poster Hall–Ballroom E/F
cytometry using fluorescent probes has been used for the evaluation of pollen DNA content in numerous species of plants ( Kron and Husband, 2015 ) and pollen response to temperature stress in arabidopsis ( Arabidopsis thaliana L.) and tomato ( Solanum
in Expt. I. Expt. III: Priming effect on seed germination under temperature stress. Seeds of each grass were placed in a 100 × 15-mm petri dish containing 20 mL of 1% agar (Sigma-Aldrich Co.) medium as described in Expt. II and placed in incubators
Thermophilic fruit vegetables, such as tomato, often suffer from suboptimal temperature stress, which is one of the limiting factors in winter vegetable production in China, leading to a decline in production and quality ( Wang et al., 2001
As global warming intensifies, the high-temperature stress response of plants has become a key research topic worldwide ( Wahid et al., 2007 ). High-temperature stress often causes a series of morphological, physiochemical, and genetic changes in
89 POSTER SESSION 13 Temperature Stress/Cross-Commodity
Watermelon [Citrullus lanatus (Thunb) Matsum. & Nakai.] seedlings may be repeatedly exposed to temperatures alternating between almost freezing and optimum soon after field transplanting. `Carnival', `Crimson Sweet', `Millionaire' and `Crimson Trio' watermelon transplants were exposed to cold temperature stress at 2 ± 1 °C in a walk-in cooler and then to 29 ± 5 °C in a greenhouse immediately before field planting to simulate temperature alternations that may occur after field transplanting. Cold-stressed transplants were field planted after all risk of ambient cold stress passed. In 1998, transplants were exposed to 2 °C from 9 hours to 54 hours, and in 1999 from 9 to 81 hours. Early yields of all cultivars, except Carnival, significantly decreased with increasing hours of cold stress in both years. Total yields of `Carnival' decreased linearly in both years with a 10% yield reduction occurring from 14 to 15 hours of cold stress. `Crimson Sweet' yields were reduced in 1999 only, with 16 hours of cold stress reducing yield 10%.
Axillary bud cultures of sweetpotato Ipomoea batatus L. [cultivars comensal and salyboro] were propagated in vitro. Nodal cultures of these were grown at different temperatures ranging from 10 °C to 30 °C at 5 °C intervals from the time of axillary bud transfer to 10 weeks of growth in a controlled growth chamber. After 10 weeks of growth, morphological and physiological parameters were measured including shoot height, number of nodes and branches, levels of proline, soluble carbohydrate and protein. There was not much difference in the cultures grown at 25 and 30 °C but temperatures lower than 25 °C were inhibitory to both cultivars, though the effects were more pronounced in salyboro than comensal. Salyboro grew slower and exhibited leaf discoloration, weak stems, and poor root growth. Proline levels increased in both cultivars and the increase was higher in shoot than root due to low temperature stress. Soluble carbohydrates and proteins increased in comensal, maintaining the carbohydrate protein ratio, but decreased in salyboro. The results suggest that the cultivar comensal may tolerate cooler temperatures and the cultivar salyboro is susceptible to them.
evolutionary history. To verify their functions in pollen, we analyzed the expression pattern in pollens of chinese white pear MAPK genes by quantitative polymerase chain reaction (qPCR) in response to temperature stresses and various hormonal changes. In
Poster Session 46—Temperature Stress Physiology 21 July 2005, 12:00–12:45 p.m. Poster Hall–Ballroom E/F