Seed dormancy, germination and seedling characteristics of Elaeocarpus prunifolius Wall. ex Müll. Berol.: a threatened tree species of north-eastern India

Abstract

Background: Elaeocarpus prunifolius Wall. ex Müll. Berol. is a threatened tree species of northeastern India. The present study was undertaken to investigate the type of dormancy prevailing in seeds of E. prunifolius, explore seed dormancy breaking techniques and assess seedling fitness. Methods: Ripe fruits of E. prunifolius were harvested from Jaintia hills, and seeds were subjected to various physical, manual and chemical treatments. The effect of plant growth regulators, viz gibberellic acid (GA 3) and potassium nitrate (KNO 3), were tested. Seedling vigour and survival based on seed weight were examined. Results: Germination took 6 months to initiate after seed dispersal and natural germination percentage of fresh seeds was 24%. Physical pre-germination treatments such as surface and acid scarification failed to overcome dormancy. Cracked seeds promoted germination (46%) with a mean germination time of 146 days (time to 50% germination, T 50 = 144 days). Among the GA 3 treatments, split seeds treated with GA 3 (3000 mg/L −1) yielded the highest germination (24%) with a T 50 of 55 days whereas KNO 3 did not promote germination. A combination of GA 3 and KNO 3 , however, increased the germination to 31%. Between the seed weight classes, the highest percentage of germination was observed in heavy seeds (25%) and the lowest in light seeds (20%). There was no significant variation between seed weight and germination time (p > 0.05). Seed weight had a significant effect on the shoot height, number of leaves and dry weight of seedlings (p < 0.05). Conclusion: Based on the seed tests, E. prunifolius seeds exhibits 'combined' dormancy (physical and physiological) as splitting seed coat and application of GA 3 effectively broke dormancy. Splitting the seed coat is a cost-effective method for accelerating germination of seeds. Heavyweight seeds produced better performing seedlings compared to their counterparts which may be viewed as an important reproductive strategy of the species.

Rethinking Iconic Species Reforestation in West Africa: Seed Shape Harnessing Is Strategic for Enhanced Germination and Vigorous Growth in Khaya senegalensis and Parkia biglobosa

“…These results were similar to those previously found in Terminalia superba, Mansonia altissima and Pterygota macrocarpa [18] and in Pterocarpus erinaceus [5]. By contrast, for some other trees species, such as Sideroxylon contrerasii and Elaeocarpus prunifolus, the germination was long, since 434 days and 146 days were required to reach maximum or mean germination, respectively [19,20].…”

“…In contrast, our findings were consistent with those of the authors of [21,22], who reported fast and better germination in large seeds in three and four tropical tree species, respectively. This result was also found by the authors of [11,20,23,24], in Pinus thunbergii, Elaeocarpus prunifilius and Terminalia bellerica. In addition, the results obtained for Parkia biglobosa agreed with those published for Copaifera langsdorffii by the authors of [25], who reported that smaller seeds showed faster and greater germination than larger seeds.…”

Seed dormancy and germination behaviour of tropical rainforest tree species from Sri Lanka

“…The dormancy classes identified for 8 of the remaining 12 species were different from those reported in the literature at the genus level (Baskin and Baskin, 2014). Our study confirmed the dormancy class previous identified or speculated at the genus level for 4 of the above 12 species [ND in genus Artocarpus (Beniwal and Singh, 1989;Elliott et al, 1996), PD in genus Elaeocarpus (Chien et al, 1998;Iralu and Upadhaya, 2018), MD in genus Gaertnera (Athugala et al, 2021) and PD in genus Glochidian (Athugala et al, 2021)]. Fourteen of the study species have been previously studied and dormancy classes were identified or speculated.…”

“…Fourteen of the study species have been previously studied and dormancy classes were identified or speculated. Six of the above 14 species have previously been studied in different ecosystems [Urophyllum ceylanicum, Turpinia malabarica, Bhesa nitidissima and Eurya ceylanica in tropical mountain forests (Athugala et al, 2021), and Messua ferrea (Troup, 1921;Joshi et al, 2015) and Dillenia indica (Thapliyal et al, 2008) in tropical semi-evergreen forests], while the rest of the species (eight) have been studied in the same ecosystem [Mangifera zeylanica and Dipterocarpus zeylanicus (Holmes, 1954), Shorea affinis (Tompsett, 1998) S. trapezifolia (de Zoysa, 1986) Strychnos benthamii (Muthuthanthirige et al, 2020) Humboldtia laurifolia (Jayasuriya et al, 2010), Gomphia serrata (Ng, 1992) and P. mooniana (Jayasuriya et al, 2013)]. The previously reported dormancy class (PD) of Bheasa nitidissima, Eurya ceylanica and Gomphia serrata are identified as ND in the present study.…”

Practical Methods for Breaking Seed Dormancy in a Wild Ornamental Tulip Species Tulipa thianschanica Regel

“…Nitrogenous compounds, such as nitrate, NO and cyanide, have a positive effect on the release of dormancy [39][40][41]. Wang reported that the application of nitrate in potato promoted the expression of a gene involved in ABA catabolism (StCYP707A1) [42].…”