Soil drought applied during the vegetative growth of triticale modifies the physiological and biochemical adaptation to drought during the generative development.

摘要

It could be taken into account that under natural conditions of plant growth, the spring drought after-effects can stimulate or inhibit the adaptation to drought during the generative growth phase of the triticale. It is expected that the response to drought during the generative growth of plants (heading and/or flowering) can be modified by the exposure to drought during the vegetative stage (tillering). Therefore, the aim of this study was to investigate whether drought occurring during the vegetative phase can modify the physiological/biochemical adaptation to drought during the generative one. The measurements of the osmotic potential, relative water content, chlorophyll fluorescence and blue fluorescence were performed. Moreover, the analysis of the total pool of phenolic compounds and cell-wall bound ferulic acid were performed. Genotypes subjected to drought during the tillering phase, maintained the osmotic regulation (high osmotic potential) during drought applied at the heading phase and, consequently, were able to maintain better leaf hydration and the functioning of the photosynthetic apparatus. The increase in the content of cell-wall bound ferulic acid, observed as an after-effect of drought applied at the tillering phase, was noticeable for the majority of genotypes. Ferulic acid bound through covalent bonds with carbohydrates of the cell wall can inhibit an increment of leaf surface. It can be linked to adaptation mechanisms, acting during drought, which can involve the inhibition of the utilization of carbohydrates in the growth processes of leaves and to maintain high osmotic potential of the cell sap.