Studies on seed priming-induced modulation of germination, plant growth and flowering in snapdragon (Antirrhinum majus L.)

Abstract

Seed priming is a pre-sowing technique used to enhance seed quality and subsequent plant performance and is widely practiced in several crop species to improve germination uniformity and yield. The present investigation was undertaken to standardize an appropriate priming protocol for snapdragon (Antirrhinum majus L.) under mid-hill conditions, with the objective of improving seed germination, seedling development, and their subsequent effects on growth and flowering. Two snapdragon selections, Snaptini Mix and Wonder land Mix, were subjected to ten seed priming treatments comprising hormonal priming with GA?, chemical priming with KNO? and KH?PO?, and bio-priming with Trichoderma harzianum and Bacillus subtilis. The results revealed that bio-priming with T. harzianum (1 × 10? cfu ml?¹) significantly improved germination percentage (from 52.62% to 76.01%), increased number of leaves (9.34), shoot length (7.92 cm), and root length (3.69 cm) compared with all other pre-sowing treatments including the control, in both selections. In addition, bio-priming with T. harzianum reduced the time required for 50% germination (9.26 days). When seedlings were transplanted under naturally ventilated poly house conditions, the residual effects of priming were evident on growth, flowering, and seed attributes in both selections. Bio-primed plants recorded higher plant height (76.35 cm), plant spread (45.29 cm), number of spikes per plant (15.06), florets per spike (24.03), and longer flowering duration (49.69 days) compared with non-primed plants. Moreover, days to flowering were reduced to 114.23 days. It is concluded that all priming treatments positively influenced germination, growth, flowering, and seed attributes of snapdragon; however, bio-priming with T. harzianum proved to be the most effective.