Temperature Effects on Cytokinin Accumulation and Kernel Mass in a Dwarf Wheat |
| |
Authors: | BANOWETZ G M; AMMAR K; CHEN D D |
| |
Institution: | USDA-ARS, 3450 S.W. Campus Way, Corvallis, OR, 97331, USA |
| |
Abstract: | The objectives of this study were: (1) to quantify post-anthesiskernel cytokinin levels in Tibet Dwarf, a dwarfwheat (Triticum aestivumL.) that accumulates elevated quantitiesof leaf cytokinins; and (2) to measure the effects of temperatureon kernel cytokinin accumulation and mature kernel mass in thiswheat. Post-anthesis kernel cytokinin accumulation was measuredin control plants maintained at 25/12 °C (day/night) andtreated plants which received a 7 d exposure to 35/25 °Cbeginning at anthesis and grown to maturity at 25/15 °C.Zeatin (Z), dihydrozeatin (diHZ) and their respective ribosideswere the predominant cytokinins detected in control and treatedplants. Minimal quantities of isopentenyl adenine-type cytokininswere detected. Kernel cytokinin content peaked within 3 d afteranthesis in both groups and returned to baseline levels within12 d. Relative to controls, exposure to high temperaturereduced kernel cytokinin content approx. 80% within 1 d afteranthesis. Because kernel cytokinin in control Tibet Dwarf plantsexceeded that previously measured in other varieties by over100-fold, the reduced content of treated plants still exceededthat of untreated plants of other varieties. The increased cytokinincontent did not enhance thermotolerance. The temperature treatmentreduced mature kernel weights approx. 27%, similar to reductionsmeasured in other wheat varieties.Copyright 1999 Annals of BotanyCompany Triticum aestivum, endosperm development, heat stress, kernel mass, cytokinins. |
| |
Keywords: | |
本文献已被 Oxford 等数据库收录! |
|