Ultraviolet-B radiation effects on the Mediterranean ruderal Dittrichia viscosa

Effects of enhanced ultraviolet-B (UV-B) radiation and suspended sediment (SS) separately as well as in combination on the growth and DNA damage of Chlorella sp. were studied under controlled laboratory conditions. The Chlorella sp. was exposed to UV-B of 17 µW cm-2for 0, 1 and 5 minutes in 0, 500 and 5000 mg L-1defined SS. The results showed that SS attenuated light penetration and suppressed the growth ofChlorellasp.. It also attenuated UV-B induced DNA damage and promoted the cell growth. The suppression and promotion of cell growth depended on the concentration of SS and dose of UV-B radiation. These results are important in understanding of the effects of elevated UV-B radiation on microalgae in sediments-dominate coastal waters.

Download Full-text

Two mire species respond differently to enhanced ultraviolet-B radiation: effects on biomass allocation and root exudation

New Phytologist ◽

10.1111/j.1469-8137.2005.01577.x ◽

2006 ◽

Vol 169 (4) ◽

pp. 809-818 ◽

Cited By ~ 19

Author(s):

Riikka Rinnan ◽

Carola Gehrke ◽

Anders Michelsen

Keyword(s):

Biomass Allocation ◽

Radiation Effects ◽

Root Exudation ◽

Ultraviolet B ◽

Ultraviolet B Radiation

Download Full-text

Ultraviolet‐B Radiation Effects on Growth and Physiology of Four Rice Cultivars

Crop Science ◽

10.2135/cropsci1992.0011183x003200050001x ◽

1992 ◽

Vol 32 (5) ◽

Author(s):

Qiujie Dai ◽

Victoria P. Coronel ◽

Benito S. Vergara ◽

Paul W. Barnes ◽

Arlene T. Quintos

Keyword(s):

Radiation Effects ◽

Ultraviolet B ◽

Rice Cultivars ◽

Ultraviolet B Radiation

Download Full-text

Allelopathic and Water Conserving Functions of Leaf Epicuticular Exudates in the Mediterranean Shrub Dittrichia viscosa

Functional Plant Biology ◽

10.1071/pp9950755 ◽

1995 ◽

Vol 22 (5) ◽

pp. 755 ◽

Cited By ~ 9

Author(s):

M Stephanou ◽

Y Manetas

Keyword(s):

Water Conservation ◽

Laboratory Experiments ◽

Photochemical Efficiency ◽

Ultraviolet B ◽

Water Soluble ◽

Considerable Decrease ◽

Ultraviolet B Radiation ◽

Lettuce Seeds ◽

Dittrichia Viscosa ◽

Mediterranean Shrub

The possible ecophysiological roles of the water soluble, epicuticular material accumulated on the leaves of Dittrichia viscosa (L.) W.Greuter (syn. Inula viscosa (L.) Aiton) (Asteraceae), were investigated in laboratory experiments. It was found that: (a) the material reduced cuticular transpiration; (b) it had a strong absorbance in the ultraviolet, apparently offering the leaves an ultraviolet-B radiation screen; (c) removal of this material, however, and exposure of the leaves to visible light supplemented with ultraviolet-B radiation had no effects on photosystem II photochemical efficiency or stomatal functions and caused no epidermal browning; and (d) the material was strongly inhibitory against germination of lettuce seeds and caused considerable decrease in the radicle length of Phlomis fruticosa L., a species often occupying the same habitat as D. viscosa. We infer from the above that D. viscosa leaves may be resistant to ultraviolet-B radiation damage and, accordingly, the water conservation and allelopathic functions of the epicuticular material may predominate over its potential to protect against ultraviolet-B radiation.

Download Full-text