Effect of various dormancy breaking treatments on seed germination, seedling growth and seed vigour of medicinal plants

Abstract

Study was conducted during 2013-14 to examine the role of various dormancy breaking treatments, viz. hot water treatment, scarification, stratification, concentrated acids (H 2 SO 4 , HNO 3 and HCl), gibberellic acid, potassium nitrate, alcohol, and acetone and gamma-rays irradiation on the percentage germination, seedling growth and seed vigour. Dried seeds were incubated in the plant growth chambers for 20-28 days at constant temperature of 25±2 °C under continuous light (16 hrs) photoperiod after its treatments. Maximum percent germination 97.2% was obtained in Innula racemosa followed by Rheum webbianum (95.1%), Carum carvi (93.4%), Saussurea lappa (90.01%) and Bunium persicum (81.4%) when seeds were pretreated with acid (H 2 SO 4 for 5 minutes). According to results obtained in present study, all studied species found best germination with H 2 SO 4 for 5 minutes in duration of 30 days. The seedlings derived from seeds exposed to the various treatments performed well when grown in a green house. Maximum length of seedlings were found in 24.3 cm in S. lappa followed by R. webbianum (23.8 cm) and C. carvi (22.2 cm) when seeds were pretreated with H 2 SO 4 for 5 minutes, on the other side B. persicum (19.4cm) in hot water treatment at 80°C for 20 minutes and I. racemosa (17.4 cm) in 0.2 KNO 3 for 10 minutes. Highest value of seed vigour index (2263) and lowest seed vigour index (390) was found in R. webbianum and B. persicum. The well developed seedlings were observed in 90 days and transplanted it for further developments. The data have implications for conservation and cultivation of the species studied.

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“…Muitos são os trabalhos que corroboram a eficácia do ácido sulfúrico na quebra de dormência física de sementes de várias espécies (Okunomo 2010;Bhardwaj et al 2016;Labbafi et al 2018;Tiwari et al 2018). Para Psidium cattleianum a escarificação ácida das sementes com ácido sulfúrico é mais efetiva em aumentar porcentagens de germinação in vitro que a escarificação mecânica (Freire et al 2017).…”

“…Em testes com sementes de Capparis spinosa, que apresentam dormência devido à presença de inibidores e ao duro revestimento das sementes, foi relatada a importância do uso de ácido sulfúrico e GA3 para aumento em até 75% na taxa de germinação (Labbafi et al 2018). Para Parkia bicolor a maior taxa de germinação foi registrada quando as sementes foram tratadas com ácido sulfúrico, indicando que o ácido aumenta a permeabilidade da semente (Okunomo 2010) Outro fator importante sobre o uso de ácido sulfúrico é o tempo de exposição, que pode reduzir significativamente a germinação das sementes, devido ao possível dano causado ao embrião ou incapacidade de quebrar a dormência física (Bhardwaj et al 2016). Sementes tratadas em ácido concentrado por um curto período de tempo tendem a apresentar melhor desempenho na germinação.…”

High Efficiency in vitro Plant Regeneration and Secondary Metabolite Quantification from Leaf Explants of Rhodiola imbricata

“…Mercuric chloride (Merck) 0.04% (w/v) having one drop of TWEEN 20 for 2-3min was added and was thoroughly washed with autoclaved distilled water 4-5 times to remove the remaining traces of sterilizing agents. 25 …”

Effects of Seed Invigoration Treatments on Seed Germination, Seedling Vigour and Physio-biochemical Characteristics of Angelica glauca EDGEW –An Endangered Medicinal Herb

“…There is little information on the germination ability and underlying physio-biochemical status of seeds of Angelica glauca (Nautiyal et al, 2002 ;Butola and Badola, 2004). Significance of presowing seed treatments to break dormancy and improve the germination ability of seeds is well established (Thakur, 2008;Bhardwaj et al, 2016;Thakur and Himangini 2015;Negi et al, 2017). Key Physiological phenomena like mobilization of stored reserves, imbibitions phenol content and other biochemical changes play a crucial role during seed germination (Yang et.al, 2016;Tejavathi et al, 2017;Zhao et al, 2018).…”