Influence of mother plant and seed coat colour on germination success of Retama sphaerocarpa L (Boissier)

Mestrado em Engenharia Florestal e dos Recursos Naturais - Instituto Superior de Agronomia - UL

The aim of this study was to determine the influence of mother-plant and seed external morphologic characteristics of Retama sphaerocarpa on germination success. Two experiments were established in a germination chamber to evaluate the influence of seed coat colour (black, brown or green) and mother-plant on germination success. A pregermination treatment of seeds for breaking seed-coat dormancy was performed soaking the seeds in hot water (80ºC) with maintenance in the same water for 24 hours (long scald). For both studies the germination rate and the vigour index were determined. The results after 28 and 162 days suggest that the seed coat colour influenced both evaluated parameters. Germination rate was highest in green-coated seeds (55.1% at 162 days), and the vigour index in brown-coated seeds (26.2). The influence of mother plant on germination rate and vigour index was also confirmed: at the end of the experiment the I5 individual presented the highest values both in germination rate and vigour index with 57.0% and 35.3 respectively, also occurring significant statistical differences between some other individuals. Consequently for seed collecting purposes, the mother-plant selection based on known performances and the seed selection based on seed coat colour may be of utmost importance to optimise seedling production in nursery