Trees, seeds and seedlings analyses in the process of obtaining a quality planting material for black locust (Robinia pseudoacacia L.)

Abstract

Black locust (Robinia pseudoacacia L.) was among the first North-American tree species imported in Europe. In Romania, black locust has established itself as a forest tree appreciated for multiple uses. The objective of the hereby study was to identify a quality planting material at black locust using seeds from trees with superior traits from five stands geographically close, located in North-western of Romania. An empirical selection was done, thus trees with the most favourable traits were selected as plus trees. Among the averages of the main traits (tree height, diameter at breast height, basal area, self pruning trunk length, crown diameter) of the plus trees from the five stands, there were registered significant differences, and two stands stood out with a high biomass growth. Even if the stands had different ages (between 20-35 year), the age did not influence significantly the growth traits of the trees. The seeds of the plus trees (open-pollinated) from all the stands had large size (mean seed weight of 0.057 g/seed). The seedling emergence rate was high, especially in the solarium condition (between 52.7-73.7% compared with 33.0-41.3% in the field). Coefficient of genetic correlation and heritability calculated for the seedlings belongings to half-sib families highlighted that black locust breeding can be extremely effective by a proper selection.

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

“…In forestry practice, it may also be sufficient to use a chemical method by immersing the seeds for 60 min in concentrated sulfuric acid, then washing the seeds in cold water and leaving them to dry at adjusted temperature [46]. Another successful method is by scarifying the seeds using manual abrasion sandpaper so that the seed coat is scratched [15,17,47].…”

“…In the absence of germination treatments, the black locust seed coat can be damaged by either low (frosts) or high (including fires) temperatures, or by the activity of soil microflora. For economic and research reasons, several methods are currently used [15]: mechanical scarification, as well as chemical and thermal procedures to increase the germination capacity. Thus, each seed lot is recommended to be tested separately to determine the proper length of time for soaking methods and type of blends to be used and their concentration, due to the variability of seed coat structure and permeability [4].…”

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

“…Normally, seed propagation is the easiest and most advantageous method of growing plants, but without previous treatments, black locust seed germination may be low due to the physiological dormancy induced by the impermeable tegument covering the seeds [40,41]. Seed propagation can be an easy and advantageous method of growing, but without previous treatments, seed germination may be low due to the physiological dormancy induced by the impermeable tegument [42], such as within Robinia species.…”