Evaluation and Modulation of Chick Pea (Cicer Arietinum L.) Productivity Under Terminal Heat Stress

Abstract

Heat stress has been considered vital ecological features to affect the plant growth and productivity. Rising temperature due to global warming resulting in heat stress that restricting the plant growth and potential productivity through out the world. Therefore, a set for four field experiments was performed at the Agronomic Research Farm area, Bahauddin Zakariya University, Multan, Pakistan to evaluate the effects of terminal heat and induce terminal heat stress tolerance in chickpea by means of osmoprotectants, phytohormones and polyamines during Rabi 2016-17, 2017-18 and 2018-19. In first study, five approved chickpea cultivars (Thal 2006, DUSHT, Punjab 2008, Bhakhar 2011 and AZC 06) were selected to screen out for their heat stress tolerance under two sowing dates (15th November and 1st December). Results of the study showed that high temperature stress adversely affects the growth, yield and quality attributes of all chickpea cultivars. However, chickpea cultivar Bhakhar 2011 showed promising antioxidant enzymatic activity under high temperature stress and produced significantly higher growth and yield contributing attributes. Where as chickpea cultivar DUSHT showed poor performance under heat stress situations.In second study, experimental treatments comprised of two chickpea cultivars(DHUST and Bhakkar 2011),two sowing dates(15th November and 1st December) and exogenous application of two osmoprotectants i.e. glycine betaine (GB) 20 ppm and proline 10 µM including distilled water (control). Results indicated that exogenous application of GB improved the growth, yield and quality parameters of both chickpea cultivars even underheat stress conditions. It was also observed that application of GB mitigates the adverse effects of high temperature stress and enhanced tolerance in chickpea mainly due to higher antioxidant enzymes activity, demonstrating the protective measures of plant cells in stress condition. In third study, experimental treatments comprised of two chickpea cultivars (DHUST and Bhakkar 2011) cultivated on two different sowing dates (15th November and 1st December) and foliar spray of two phytohormones i.e. Benzyl-amino purine (BAP 50 mg/L) and Moringa leaf extract (MLE30) including distilled water as a control.Results indicated that foliar spray of MLE improved the growth and yield contributing attributes, which ultimately increased the final productivity. Moreover, exogenously applied MLE significantly modulated superoxide dismutase, peroxidase and catalase enzymatic activitiesand minimize the adverse impacts of heat stress on yield contributing traits. In fourth study, experimental treatments comprised of two chickpea genotypes (Bhakhar 2011 and DUSHT), two sowing dates (15th November and 1stDecember) and exogenous application of two polyamines i.e. Arginine 2.5 mM and Putrescene 2 mM including distilled water (control). Outcome of the study showed that exogenously applied Putrescene improved the growth, yield and quality parameters of chickpea even under heat stress situations. It was also observed that application of Putrescene alleviates the adversative influences of heat stress and improved tolerance in chickpea cultivars primarily due to higher antioxidant enzymes activity, demonstrating the protective measures of plant cells in stress condition.