Influence of mother plant and scarification agents on seed germination rate and vigor in Retama sphaerocarpa L. (Boissier)

Abstract

The aim of this study was to optimize nursery production of Retama sphaerocarpa, an important shrub species in some plant communities of arid and semi-arid zones, which is used in the restoration of degraded areas. This Fabaceae family species has seed coat dormancy, which may hinder germination. In order to assess the influence of scarification agents and mother plant effect on germination rate and seedling vigour, a germination test with fresh seed was performed in a germination chamber, following a factorial design with two fixed factors (mother plant effect and scarification agent). The test took place in the forest nursery of the Institute of Agricultural Sciences, Lisbon, Portugal. The fresh seeds were subjected to scarification by two agents, sulphuric acid (96% concentration) and hot water (80°C), the former for 60 minutes and the latter for 30 seconds, plus an untreated control. The scarification of seeds using sulphuric acid was found to be the best method to enhance germination of this species (p79%) and the best vigour index. Differences between mother plants were also statistically significant and could influence germination success. We suggest that effectiveness of hot water scarification may be improved by additional time of seed immersion. The technical viability for seed production of this species was confirmed and key factors for its success identified. Owing to its potential for use on land rehabilitation, increment on plant commercial demand should be expected in the near future.

Keywords

• Fresh Seed
• Germination
• Mother Plant
• Retama sphaerocarpa
• Scarification
• Vigor