IMPACT OF BORON SEED PRIMING ON THE GROWTH, YIELD, ANTIOXIDANT POTENTIAL, TOTAL PHENOLIC AND FLAVONOID CONTENTS OF HELIANTHUS ANNUUS L.VAR AGSUN 5264 MEDIATED WITH INDOLE ACETIC ACID APPLICATION.

Abstract

Helianthus annuus is an important economic crop which yields high edible oil contents and is feasible to be cultivated in almost all agroclimatic conditions and soils. This plant not only covers the food based energy needs but also known for therapeutic impacts. Majority soils in Pakistan are boron deficient and responsible for low crop yields. Boron is required by plants in very small quantities and the rate of agricultural production is determined by its availability in soil and irrigation water. Several morphological, physiological and biochemical parameters are disrupted due to fluoride sequestration in areas surrounding plant roots and mesophyll cells. In present study, seeds of Helianthus annuus L. var. Agsun 5264 were subjected to boron priming treatments. Seeds were primed with five treatment levels of boric acid (0, 0.001%, 0.01%, 0.1% and 0.5%). Seeds were primed overnight in aerated channels. Seeds were sown in earthen pots on the next day. Pots were positioned according to the complete randomized block design. Final harvest was done when plants were fully grown. Various physical parameters i.e, seeds/head, head diameter, root and shoot length, root fresh and dry weight were recorded.  The antioxidant activity was determined in terms of DPPH radical scavenging. The phenolic and flavonoid contents were also determined. The Results of boron treatment mediated with indole acetic acid evidently showed that 0.1% and 0.5% solutions of boric acid as a boron source not only improved the yield and growth parameters but also induced high antioxidant response, phenolic and flavonoid production which added a substantial therapeutic and functional aspect in plant for human consumption.