The aim of this study was to identify a fluorescence parameter whose estimate could be used reliably for a drought tolerance test in durum wheat (Triticum durum). Twenty five cultivars were grown in a glasshouse over two seasons (1987/88 and 1988/89) at Foggia, Southern Italy. Photochemical and non-photochemical quenching (qQ and qE), the half time of fiuorescence decay (tP1/2) and the initial slope of fiuorescence decay (ISps) were measured on control and dehydrated pre-darkened excised leaves; qQ and qE were measured twice: first at 14 s after actinic illumination and second at the steady state. No great difference in qQ and qE was apparent between control and dehydrated leaves at the steady state; however, at 14 s after illumination there was a decrease in qQ and in ISPS and an increase in tPl in dehydrated leaves. The predictive capability of fluorescence parameters was assessed by comparison with a yield-based drought susceptibility index (DSI). The percentage decrease in qQ at 14 s showed the highest correlation with DSI (r = 0.75, significant at P< 0.001), so it may be considered a good indicator of drought tolerance in durum wheat. Results obtained at different developmental stages with different fluorescence levels (Fo, P and Fm) and parameters (qQ, qE and tP1/2) indicated that for maximum reliability the test must be applied at the vegetative phase. © 1994 Cambridge University Press.
Photochemical quenching of chlorophyll fluorescence and drought tolerance in different durum wheat (Triticum durum) cultivars
FLAGELLA, ZINA;PASTORE, DONATO;
1994-01-01
Abstract
The aim of this study was to identify a fluorescence parameter whose estimate could be used reliably for a drought tolerance test in durum wheat (Triticum durum). Twenty five cultivars were grown in a glasshouse over two seasons (1987/88 and 1988/89) at Foggia, Southern Italy. Photochemical and non-photochemical quenching (qQ and qE), the half time of fiuorescence decay (tP1/2) and the initial slope of fiuorescence decay (ISps) were measured on control and dehydrated pre-darkened excised leaves; qQ and qE were measured twice: first at 14 s after actinic illumination and second at the steady state. No great difference in qQ and qE was apparent between control and dehydrated leaves at the steady state; however, at 14 s after illumination there was a decrease in qQ and in ISPS and an increase in tPl in dehydrated leaves. The predictive capability of fluorescence parameters was assessed by comparison with a yield-based drought susceptibility index (DSI). The percentage decrease in qQ at 14 s showed the highest correlation with DSI (r = 0.75, significant at P< 0.001), so it may be considered a good indicator of drought tolerance in durum wheat. Results obtained at different developmental stages with different fluorescence levels (Fo, P and Fm) and parameters (qQ, qE and tP1/2) indicated that for maximum reliability the test must be applied at the vegetative phase. © 1994 Cambridge University Press.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
