Hydropriming -a useful technique for seed invigoration in okra (Abelmoschus esculentus) and parsley (Petroselinum crispum)

Abstract

Seed germinating ability and stand establishment determine the management options in crop production system. Physiological advancement of seeds through priming is a simple and cost-effective method to improve the germinability and stand of any crop. Studies were performed on seed invigoration through hydropriming at the division of PHT, SKUAST-Kashmir during the year 2016 to optimize the hydropriming duration for improved germi-nation and seedling vigour of okra (Pusa sawani) and parsley (curly type). Freshly harvested seeds were soaked in normal water for varying durations (okra- 12, 18 and 24 h; parsley- 24, 48 and 72 h) at (25±2°C) and re-dried to original moisture content at room temperature. Fifty seeds of each treatment were cultured in 14.0 cm Petri dishes lined with 5 layers of moist blotting paper. Observations on various germination parameters were recorded at (25±2°C). Priming of okra seeds for 18 h resulted in highest FGP (85.7%), GE (66.5%), GI (36.7), SDB (29.1mg) and SVI (2.49) coupled with minimum values of T50 (2.75 day) as well as MGT (2.38 day). However, the highest FGP (78.7%), GE (48.7%), SDB (3.13 mg), GI (12.8) and SVI (0.25) together with minimum T50 (7.2 day) and MGT (6.5 day) in parsley was recorded with 24 h priming duration. As such priming duration of 18 and 24 hours at 25±2°C were found optimal for enhanced and rapid seed germination with vigourous seedlings.

Priming Strategies for Parsley Seedling Production

“…The TE of parsley seeds was also reduced by 44% for cultivar Krausa and 20% for cultivar Titan when seeds were imbibed for 96 h compared with 24 h. Results corroborate with previous studies using hydropriming on parsley (Dursun and Ekinci, 2010;Kamau and Maina, 2017). Particularly, the imbibition of parsley seeds in water for 24 h was reported to increase ESI compared with untreated seeds (Khan et al, 2017), indicating that finds of the present study highlighted that 24 h of water imbibition is enough to increase both ESI and TE of parsley without damage seed development.…”

“…Use of priming agents on parsley seeds. Hydropriming is an easy and low-cost priming technique used in vegetable nurseries and benefits of hydropriming were previously reported in onion (Caseiro et al, 2004), carrot (Eisvand et al, 2011), pepper (Sanchez et al, 2001), cucumber (Sanchez et al, 2001), and even parsley (Khan et al, 2017). Nevertheless, long periods of contact between water and parsley seeds induce negative effects on the germination process (Hassell and Kretchman, 1997).…”

“…The goal of the osmopriming technique is to extend the phase II of germination, when seeds are digesting reserve substances and mobilizing protein to germination (Khan et al, 2017). Consequently, seeds treated with osmopriming agents tend to provide increased emergence due to increased cell size, cell number, and volume of the seed embryo (Chen et al, 2010;Dawidowicz-Grzegorzewska and Maguire, 1993;Gray et al, 1990).…”

“…As mentioned earlier, the benefits of priming techniques were previously reported in several other crops, but priming techniques evaluated in the present study had minimal to no impact on parsley seeds. This is mostly due to the fast germination of kale seeds and the coumarin toxin released after the rupture of the integument (Khan et al, 2017).…”

“…Among the evaluated priming techniques, hydropriming (seed water imbibition for 24 h) and osmopriming (seed imbibition in PEG6000 at -2.0 MPa for 116 h) were the techniques that significantly increase ESI, whereas hydropriming (seed water imbibition for 24 h) increased TE. Osmopriming (PEG8000 at -0.5 MPa) (Sanchez et al, 2001) and seed water imbibition for 24 h (Dursun and Ekinci, 2010;Khan et al, 2017) were previously reported to increase the percentage and rate of seed germination compared with untreated seeds in parsley. Particularly, parsley seeds treated with water for 48 h and PEG600 for 24 and 48 h improve germination and number of normal seedlings compared with untreated seeds (Kamau and Maina, 2017).…”