Impact of global warming through drought stress simulation on morphological features of Ananas comosus l. (pineapple) var. MD2 clonal plantlets

Abstract

Nurul Izzati Osman, Nor Syuhadah Azmi, Diyana Sakinah Mohamed Soder, Asmah Awal, Jamaliah Laham

Extreme high temperature has become more common as a result of global warming which acts as a key abiotic stress that inhibits plant development and productivity. In this research, drought-exposed Ananas comosus clonal plantlets were triggered to specific physiological responses to overcome the effect of drought stress. The plantlets of A. comosus were placed in a greenhouse with recorded temperatures ranging between 32°C to 36°C and treated with three different watering conditions which are once a week (Treatment 1/control), once every two weeks (Treatment 2), and not watered at all (Treatment 3). The first obvious morphological effect is wilting, drying out of the tips or edge of leaves, and yellowing or browning of leaves. Treatment 1 (control) recorded the lowest plant wilting number and the highest in the mean of leaves length among other samples. In Treatment 2, a higher amount of plant wilting with a lower amount in the mean of leaves length as compared to Treatment 1 was observed. Meanwhile, Treatment 3 recorded the highest wilting record as well as the lowest mean of leaves length. The physiological changes in stomata conductance have greater conductance for Treatment 1 with more open stomata and obvious pores followed by Treatment 2 with stomata opened slightly and Treatment 3 was observed to have sunken stomata and the pores were hardly seen. The physiological changes of stomata have shown the mechanism of adaptation in clonal plantlets to control transpiration and prevent dehydration under thermal and drought stress.