Effects of thermal-time artificial scarification on the germination dynamics of black locust (Robinia pseudoacacia L.) seeds

Abstract

The aim of this study was to determine the efficiency of methods for the artificial scarification of black locust seeds based on the influence of the air and liquid nitrogen temperatures. Three populations were selected for the analyses: a managed tree stand, a selected seed stand and a seed orchard. Samples of 200 seeds (4 9 50) were randomly selected. Before scarification, the seeds were stored at -70°C for 24 h. Nine different scarification treatments were evaluated. To calculate the germination capacity and the dynamics of germination, observations were made on days 3, 5, 7, 10 and 14 after treatment. For statistical analyses, we used repeated measures analysis of variance. The obtained results indicated that the highest scarification efficiency for black locust seeds occurred in the treatment in liquid nitrogen and in an air temperature range of 85-90°C. The provenance of seeds had a significant effect on the dynamics of germination. Thermal methods and the use of liquid nitrogen can be alternatives to the labour intensive methods of cutting the seeds or using measures that require specialised equipment.

From Seed to Seedling: Influence of Seed Geographic Provenance and Germination Treatments on Reproductive Material Represented by Seedlings of Robinia pseudoacacia

“…When the seed tegument is damaged, water infiltrates and initiates the germination process. For the Robinia genus, the proportion of seeds capable of germination without any treatment is usually low, as evidenced by the average level of 10.8% obtained in the past [39]. The obtained results also showed a very low germination (2.18%) without any treatment.…”

Ecology, growth and management of black locust (Robinia pseudoacacia L.), a non-native species integrated into European forests

“…Because the heavy, thick and impermeable seed coat restricts germination, the seeds need pre-treatment to remove seed dormancy. In both native range (Olson 1974;Harlow et al 1986) and in Europe (Bîrlănescu and Belu 1968;Costea et al 1969;Savill 2013;Jastrzębowski et al 2017;Pedrol et al 2017), mechanical scarification using rotary tools or electric grinders, soaking in concentrated or diluted sulphuric acid, soaking in boiling or nearly boiling (70-80 °C ) water, using low liquid nitrogen or high temperatures in an incubator are the usual methods. After appropriate pre-sowing treatment, germination rates can be as high as 85.0 ± 5.8% (Kheloufi et al 2018) or 89.0-100% (Cierjacks et al 2013;Vuković et al 2013).…”

Seed Germination and Seedling Growth of Robinia pseudoacacia Depending on the Origin of Different Geographic Provenances

“…The Robinia genus includes 19 botanical taxa, eight of which are classified as species, while the others are considered natural varieties or hybrids [1,2]. Black locust (Robinia pseudoacacia L.) is native to the eastern part of North America-the Appalachian region [3,4].…”

“…Under natural conditions, the coat of black locust seeds can be damaged by either low (frosts) or high temperatures (fires) or by the activity of the soil microflora [47]. For research and practical purposes, three methods are used: mechanical (scarification), thermal and chemical [2,48].…”