Vodní deficit a jeho vliv na fyziologické projevy u vybraných odrůd květáku (Brassica oleracea var. botrytis L.)
Authors: H. Hniličková, J. Duffek
Page: 57-63
English / Anglicky:
The effect of short-term and long-term water stress was studied in cauliflower (.Brassica oleracea var. botrytis L., the varieties Opaal, Ambition, Spacestar, Siria and Fremont) as affected the rate of photosynthesis (PN), rate of transpiration (E) and stomatal conductance (gs) in the years 2000 and 2001. Plants of cauliflower were cultivated in the greenhouse (average temperature 20/16 °C day/night) in pots 120 mm in diameter in the control (C) (watering on the level of 30 % volume of soil moisture, what means the value of soil water potential -0.12 MPa, at pH 7.0) and the stressed variant (S). Watering was discontinued for five days in stressed plants in short-time water stress and in long-time water stress watering was reduced to 17 % of the volume of soil moisture for 22 days, i. e. soil water potential was -1.28 MPa. With passing water stress stomatal conductance was falling together with the rate of photosynthesis and transpiration. The rate of photosynthesis ranged between 11.9 and 39.4 % on the fifth day of dehydration of the rate of photosynthesis of the control plants. The difference in the rate of photosynthesis between the control and stressed plants on different dates of measurement was statistically significant (F =22.3195, p = 0.000167, Table 3, Fig. 3). The variety Opaal was most resistant and the variety Ambition was most sensible. The rate of photosynthesis in stressed and control plants was equal on the third day of rehydration. We did not record the values comparable with control plants to the end of experiment in stomatal conductance and the rate of transpiration. Resistance of cauliflower plants to water deficit was recorded in long-time action on the 10th day of dehydration when stressed plants reached the values of the rate of pho