Chlorophyll and photosynthetic oxygen evolution in water-stressed triticale (Tricosecale Wittmack) and wheat (Triticum aestivum L.) during vegetative stage

Abstract

The aim of this work was to compare the effects of water deficit on chlorophyll content, chlorophyll fluorescence and photosynthetic oxygen evolution in the drought tolerant triticale (tricosecale wittmack; Triticum aestivum L. x Secale cereale L.) cv. Eronga and the wheat (Triticum aestivum L.) cv. Temporalera (tolerant to water stress) and Ciano (sensitive to water stress) during the vegetative stage. Triticale and wheat cultivars were grown in a greenhouse. Water deficit was induced by withholding irrigation during 15 days after the first to fourth leaf blade had emerged. After each of these periods, plants were well-watered. Chlorophyll content, chlorophyll fluorescence and photosynthetic electron transport were evaluated after water deficit and after rewatering. Except for the rate fluorescence variable/maximum, significant interaction genotype x water condition x number of leaf can be interpreted as indicating that genotype x water condition relation differs depending on the developmental stage (leave number exposed) when deficit water was induced. It was clear that when the third leaf blade had emerged water deficit induced substantial alterations. Rewatering affected chlorophyll content and this did not depend on the genotype; in contrast, in chlorophyll fluorescence and oxygen evolution genotype x re-watering condition depended on the leaf number. In both, wheat and triticale, the third leaf blade hardly recuperated their physiological activities after re-watered.