WATERLOGGING AFFECT THE DEVELOPMENT, YIELD AND COMPONENTS, CHLOROPHYLL CONTENT AND CHLOROPHYLL FLUORESCENCE OF SIX BREAD WHEAT GENOTYPES (TRITICUM AESTIVUM L.)

M. B. Salem, M. Amri, M. H. El Ouni

Abstract: During rainy crop seasons waterlogging is a serious environmental stress influencing wheat development and production in the North West zones of Tunisia. A field trial was conducted during the two cropping seasons 2005/06 and 2006/07at Oued-Béja Agricultural Experimental Unit (36°44’N; 9°13’E) under rainfed and waterlogging conditions in order to evaluate flooding effects on development, chlorophyll fluorescence, chlorophyll content, yield and components for six bread wheat genotypes (Triticum aestivum L.). The floodwater state was applied during 28 days at the tillage stage. The results indicated that waterlogging has significantly affected (P<0.01) the vegetative development, physiological traits and yield and components for all studied genotypes. Waterlogging delayed the heading by 9.6 days and reduced the plant height and the tiller number per plant (TN/P) by 25.4% and 44.2% respectively. This vegetative growth limitation resulted in an average decrease of 55.9% in grain yield. The genotype Salammbô presented the lowest levels of yield reduction (≈ 39% and 39.6%) against a reduction of 71.8% and 76.5% recorded for cv. Vaga. In addition, clear variation in chlorophyll fluorescence (Maximum quantum efficiency: Fv/Fm) and chlorophyll content were observed between controls and waterlogged plants. For chlorophyll content index, minima decreases of 41.3% and 44.5% were recorded after 28 days of waterlogging respectively for cv. Salammbô and cv. Utique against maxima of 58.5%, 58.9% and 60.7% recorded for cv. Vaga, FxA and cv. Ariana, respectively. Under water excess conditions Fv/Fm of Vaga and Ariana genotypes were more affected than cvs. Salammbô and Utique.

Keywords: chlorophyll fluorescence; grain yield; Triticum aestivum; waterlogging

Date published: 2019-04-19