Preliminary responses of some Thai rice cultivars to simulated acid rain stress during seed germination

Abstract

Germination response of nine Thai rice (Oryza sativa) cultivars was investigated under simulated acid rain at pH values of 2.5, 3.5, 4.5, 5.5 and a control at pH 6.5 using a split-plot in completely randomized design (CRD) with three replications as main plots and subplots. Germination percentage, seedling characteristics and inhibitory responses were evaluated. Results showed that rice seed germination decreased after exposure to simulated acid rain of pH 2.5, 3.5 and 4.5 compared to the control. Acid rain significantly decreased seedling root length, root-to-shoot ratio and crown roots per seedling while pH 2.5 completely inhibited all the investigated seedling characteristics. Average values of germination percentage reduction were highly significant in KDML105 and RD27 cultivars while acid rain stimulated rice seed germination in HPYTD, RD57, MLL and TTCP, suggesting that these cultivars are tolerant to acid rain stress during seed germination.

Morphological and biochemical changes in shoot and root organs of common vetch (Vicia sativa L.) after exposure to drought stress

“…Drought stress in plants induces many physiological and biochemical changes, making the maintenance of osmotic adjustment extremely necessary [19]. In addition, acid rain, another abiotic stress, was shown to cause a decrease in root/shoot length ratio and seed germination in rice [20]. Among all the changes, the most important ones involve enzymes and osmoregulation, which are the main components of the antioxidant defence mechanism.…”