Role of Chilling Temperature and Chilling Duration in Overcoming Physiological Seed Dormancy in Lisianthus (Eustoma grandiflorum Shinn.)

Abstract

Chilling treatment is an effective method to improve the seed germination efficiency of Lisianthus. Further, there is limited research on the combined influence of different chilling temperatures and treatment durations on germination behaviour, seedling vigour and early seedling development. Therefore, the present study focused on the influence of different chilling temperatures and durations on germination and its attributing characters of Lisianthus. The experiment consisted of 16 treatments and three replications. Among the different chilling treatments, the seeds exposed to 3°C for 11 days (T2D3) had a positive impact on most of the germination and seedling parameters viz., germination (93%), germination energy (91.60%), germination value (6.13), less days taken for initiation and completion of germination (7.00 and 11.04, respectively), less mean germination time (6.26 days), more survival rate (76.33 %), vigour index (1066), highest plumule (5.27mm) and radicle length (6.20mm), took less time for emergence of first true leaf pair (7.33 days), second true leaf pair (21.33 days) and third true leaf pair (35.33 days), highest seedling fresh (2.10 g) and dry weight (0.63 g). From this study, it can be concluded that chilling at 3°C for 11 days can be used to improve seed germination of Lisianthus seeds, as it effectively weakened the endosperm barrier and stimulated α-amylase activity, which facilitated faster germination and balanced seedling growth.