Čeština
EnglishContribution of leaves of different ages to plant carbon balance as affected by potassium supply and water stress
Čatský J., Velichkov D.K., Pospíšilová J., Solárová J., Tichá I.
BIOLOGIA PLANTARUM 29: 355-364, 1987
Keywords: photosynthesis, respiration, carbon dioxide, potassium, water stress, leaf insertion
Abstract: Abstract. The carbon balances of whole, 21-d old French bean plants (Phaseolus vulgaris L.) grown in standard nutrient solution (1K) and its modifications without (OK) or surplus (2K) potassium were calculated from the daily photosynthetic carbon inputs of individual leaves, and the daily respiratory carbon losses by individual leaves, stalks and petioles, and roots. Under the three K concentrations, maximum net photosynthetic rates (PN) were found in the 2nd or in the 3rd trifoliate leaves, maximum respiratory rates (RD) in the youngest, 4th trifoliate leaves; the PN/RD ratio decreased with leaf age. In all leaves of 2K plants, leaf dry masses and thicknesses, PN, PN/PD ratios, and stomatal and intracellular conductances were lower than in OK and 1K plants. Daily whole-plant net carbon gain was highest in 1K plants, whereas in OK and 2K plants it was 98.0 and 81.3 % of 1K, respectively. Similar values were found in the parameters of growth analysis, namely in not assimilation rates and relative growth rates. No differences were found in water potential (~w) or water saturation deficit (Wsat) in the OK, 1K and 2K plants sufficiently supplied with water or during wilting and resaturation. The decrease in ~w to --0.97 MPa was associated with a 19.9 O/o, 31.4 % and 23.4 % decrease in P~ of OK, 1K and 2K plants, respectively, but no effect on RD was found. In the three variants, the short-time effect of mild water stress was fully reversible.
DOI: 10.1007/BF02886614
IEB authors: Jana Pospíšilová
BIOLOGIA PLANTARUM 29: 355-364, 1987
Keywords: photosynthesis, respiration, carbon dioxide, potassium, water stress, leaf insertion
Abstract: Abstract. The carbon balances of whole, 21-d old French bean plants (Phaseolus vulgaris L.) grown in standard nutrient solution (1K) and its modifications without (OK) or surplus (2K) potassium were calculated from the daily photosynthetic carbon inputs of individual leaves, and the daily respiratory carbon losses by individual leaves, stalks and petioles, and roots. Under the three K concentrations, maximum net photosynthetic rates (PN) were found in the 2nd or in the 3rd trifoliate leaves, maximum respiratory rates (RD) in the youngest, 4th trifoliate leaves; the PN/RD ratio decreased with leaf age. In all leaves of 2K plants, leaf dry masses and thicknesses, PN, PN/PD ratios, and stomatal and intracellular conductances were lower than in OK and 1K plants. Daily whole-plant net carbon gain was highest in 1K plants, whereas in OK and 2K plants it was 98.0 and 81.3 % of 1K, respectively. Similar values were found in the parameters of growth analysis, namely in not assimilation rates and relative growth rates. No differences were found in water potential (~w) or water saturation deficit (Wsat) in the OK, 1K and 2K plants sufficiently supplied with water or during wilting and resaturation. The decrease in ~w to --0.97 MPa was associated with a 19.9 O/o, 31.4 % and 23.4 % decrease in P~ of OK, 1K and 2K plants, respectively, but no effect on RD was found. In the three variants, the short-time effect of mild water stress was fully reversible.
DOI: 10.1007/BF02886614