Abstract
Responses of canola (Brassica napus L.) seedlings to three ultraviolet (UV)-B levels [0 (zero), 5 (ambient) and 10 (enhanced) kJ m-2 d-1], two watering regimes (well-watered and water-stressed), and two abscisic acid (ABA) levels (with and without application) were investigated. Overall, enhanced UVB and water stress negatively affected plant growth and physiology, but ABA had very little effect. Enhanced UVB decreased stem height, leaf area, plant dry matter, water use efficiency and wax content, but increased concentrations of chlorophyll a, carotenoids and flavonoids, and ethylene evolution. Water stress reduced stem height and diameter, leaf area, plant dry matter, leaf weight ratio and shoot:root weight ratio under zero and ambient UVB. Water stress also reduced chlorophyll a and carotenoids in plants exposed to enhanced UVB. ABA with watering regime had significant interactive effects only on leaf dry matter and wax content. We found that enhanced UVB and water stress adversely affected B. napus seedlings. Interaction between these two factors affected plant performance. In this interaction, ABA had little significant role. Also, optimum vegetative growth and biomass were achieved under ambient UVB.
| Original language | English |
|---|---|
| Pages (from-to) | 212-219 |
| Number of pages | 8 |
| Journal | Environmental and Experimental Botany |
| Volume | 66 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - May 2009 |
| Externally published | Yes |
Bibliographical note
Funding Information:We thank the Natural Sciences and Engineering Research Council (NSERC) of Canada for financial support through Discovery grants to D.M. Reid and C.C. Chinnappa. A sabbatical leave provided to M.H. Sangtarash by the University of Sistan and Baluchestan of Iran is greatly appreciated. The authors also thank Ms. Bonnie Smith for help with growth chamber setup.
ASJC Scopus Subject Areas
- Ecology, Evolution, Behavior and Systematics
- Agronomy and Crop Science
- Plant Science