Using automated sanding to homogeneously break seed dormancy in black locust (Robinia pseudoacaciaL., Fabaceae)

Abstract

Physical dormancy of Robinia pseudoacacia seeds makes it a challenge for scientists and forest managers to obtain a homogeneous germination for larger seed samples. Water imbibition of the seeds can be achieved through manual piercing of the seed coat, but this method remains time consuming and heterogeneous. We tested several ecologically friendly methods to break seed dormancy, including manual pin puncture, water soaking, oven dry-heating (two temperatures) and sanding. Sanding was performed using an automatic grinder to control shaking duration (three durations) and get a homogeneous scraping of the coat. All methods, except dry-heating, resulted in successful dormancy breaking; water soaking was the least efficient method, attaining 57% germination. Sanding proved to be as efficient as puncturing (97%) but long duration sanding (10 or 15 min) could damage cotyledons, which would impede further development of the plant. Short-time sanding (5 min) proved to be the best method to reach high total germination and healthy (undamaged cotyledon) seedlings, and was successfully applied to 500 seeds. The reference puncture method and the automatic sanding were also tested on seeds of nine Fabaceae species and proved to be efficient for some species. Automated sanding can thus be used as a standard to break physical dormancy of black locust or other Fabaceae seeds to allow further comparative studies of plant populations or genotypes.

A few north Appalachian populations are the source of European black locust

“…The plant material was then crushed using an automated grinder (2010 Geno/Grinder, SPEX SamplePrep, Metuchen, NJ, USA). For four populations (Corphalie, Drewnica, Pinczow and Lewisburg), a few seeds from ten sampled mother trees were scarified and grown in the laboratory (Bouteiller, Porté, Mariette, & Monty, 2017 (Bouteiller et al, 2018).…”

No evidence for genetic differentiation in juvenile traits between Belgian and French populations of the invasive tree Robinia pseudoacacia

“…A controlled experiment was set up in two climatic chambers (Fitoclima D1200, Aralab, S Domingos de Rana, Portugal) with a total of 2000 individuals: five seeds corresponding to half-sibs × 10 maternal trees × 10 populations × 2 geographic range × 2 climatic chambers. Prior to seeding, seeds were mechanically scarified using an automated sand blasting technique (Bouteiller et al 2017) to ensure a controlled dormancy breaking. Seeds were sowed into plastic trays (QuickPot 35RW, HerkuPlast Kubern GmbH, Ering, Germany); each pot was filled with 25 g of substrate (Substrate 307, Peltracom, Gent, Belgium) plus 6 g after sowing to cover the seeds (Bonner & Karrfalt 2008).…”

“…GDD were calculated by multiplying the climatic chamber day temperature condition (in °C) and the number of days spent in the climatic chamber, base temperature was considered equal to 0 since no reference value was found for black locust. Five phenological stages have been defined as follows: 1, emergence; 2, straight stem; 3, open cotyledons; 4, first leaf; 5, second leaf (see Bouteiller et al 2017 for details and photographs of the phenological stages). According to air temperature, the phenological survey was stopped after 20 days in the warmer climatic chamber and after 25 days in the colder cli- Pl.…”

“…To evaluate the germination rate of R. pseudoacacia seeds among ranges and temperatures, we constructed a germination curve on the fraction of germinated seeds, G(t) (for more details see Bouteiller et al 2017). A Gompertz model was fitted using a Bayesian procedure (equation 1).…”

Substantiation of work quality indicators of the universal seeds scarificator of the eastern galega (<em>Galega Orientalis</em>)

“…The researchers Luo et al (2013) created and tested the design of the 9BQS-3.0 machine with a pneumatic scarification and sowing complex, which proved to be quite good in simultaneous operations of seed scarification and sowing in China. The researchers Bouteiller et al (2017) conducted research on the use of an automatic grinding machine for forest seeds and recommended shortterm grinding (5 min) to achieve the best results. In the USA, a mechanical electric drum scarifier coated with 80 grit sandpaper was used to scarify Waltheria indica seeds, ensuring seed germination after treatment for 15 or 30 s by 95% and 99%, respectively (Lukas et al, 2016).…”