| Abstract Detail
Environmental Physiology Villegas, Daniel [1], Alcalde, Jose Antonio [2]. A two-plane response to temperature and photoperiod in Arabidopsis thaliana: the result of two different processes in the control of flowering time? Flowering time is the most important phenological event determining adaptation to the environment in annual plants. Among several environmental factors affecting flowering time, temperature (T) and photoperiod (P) are the most important, and plants show great genetic variation to them. Roberts and Summerfield (1987) proposed a so-called Linear Photothermal Model to predict flowering time (f) in which the rate of progress to flowering (i.e. the reciprocal of f, or 1/f) is a linear and additive function of average T and P from sowing to flowering. This model has been shown to fit well to several crops plants (e.g. peas, soyabean, cowpea) allowing quantification of the effects of different genes that modify the responses of 1/f to T and P and their influence on adaptability to different enviroments. One of the objectives of this research was to test if the model can be used to predict flowering time in Arabidopsis. To do this six ecotypes known to vary widely in time to flowering were grown under a minimum of twelve different photothermal environments (10 to 25 °C temperature and 10 to 20 h d-1 photoperiod range). Times from sowing to first flower varied from 28 to 38 d under a 20 h d-1/25 ºC photothermal environment for the earliest (Ws) and the latest (Stc) ecotypes, respectively, and from 67 to 105 d for the same ecotypes, under 16 h d-1/10 ºC photothermal environment, respectively. All six ecotypes exhibited a photothermal plane response where flowering time is determined by T and P, and three of them (Col, Li-5 and Stc) also showed a photothermal range in which time to flowering was determined by temperature alone. The interpretation of these response planes as representing two different processes in the control of flowering time is discussed.
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1 - Universidad Catolica de Chile, Facultad de Agronomia, Dpto Fruticultura
2 - Universidad Catolica de Chile, Facultad de Agronomia, Dpto Fruticultura, Vicuña Mackenna 4860, Santiago, 690-4011, Chile
Keywords:
Environment adaptability
Linear Photothermal Model
Flowering prediction.
Presentation Type: Plant Biology Abstract
Session: P
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM
Number: P01038
Abstract ID:1711 |
