Morpho‐colorimetric analysis and seed germination of Brassica insularis Moris (Brassicaceae) populations

Abstract

Brassica insularis is a perennial plant growing on both coastal and inland cliffs. Three seed lots from Sardinia were analysed using an image analysis system to detect differences in seed morphology, both within and among populations. Germination requirements at constant (5-25 °C) and alternating temperatures (25/10 °C), both in light and in darkness, were evaluated for all populations. In addition, the effect of a dry after-ripening period (90 days at 25 °C) was also investigated. Morpho-colorimetric analysis clearly identified seeds from different populations and discriminated three chromatic categories for seeds belonging to the Isola dei Cavoli coastal population, but not for the inland Masùa and the coastal Planu Sartu. Inter-population variability was also observed in germination behaviour. B. insularis seeds germinated, with percentages up to 60%, in a wide range of temperatures (5-25 °C), and neither light nor dry after-ripening affected final germination percentages. Moisture content measurements were made for seeds of each colour, but there were no particular differences among colours. Inter-populational variability in germination behaviour may be a survival strategy for species growing under unpredictable environmental conditions, such as under Mediterranean climate, while heteromorphy may be due to independent evolutionary divergence processes of the Isola dei Cavoli population.

Effects of NaCl stress on seed germination and seedling development of Brassica insularis Moris (Brassicaceae)

“…The light inside each growth chamber was provided by nine white light fluorescent lamps (Mitsubishi OSRAM 40;53 W each). Germination tests were conducted only in the light because our previous study indicated that B. insularis seeds germinate both in the light and in the dark, without significant differences (Santo et al 2015a). The interpopulation variability in salt stress response was evaluated by testing germination under the following NaCl concentrations (0, 200, 400 and 600 mM) at 15 and 25/10°C for seeds from the Br2 and Br3 populations (Table 1).…”

“…Brassicaceae seeds can be physiologically dormant (PD) or non-dormant (ND) (Finch Savage & Leubner-Metzger 2006). A recent study (Santo et al 2015a) highlighted the variability among populations during seed germination and in seed morphology in relatively close populations (<8 km) of B. insularis. The same study also showed that B. insularis seeds could germinate throughout a wide period of the year.…”

Description of olive morphological parameters by using open access software

“…Most of the studies based on morphological descriptors which have been adopted by the International Union for the Protection of New Varieties of Plants (UPOV) focus on the morphological characteristics of leaves, fruits and endocarps. Traditionally, these characteristics have been widely used for descriptive purposes to distinguish olive cultivars [3, 14–18]. Several descriptors which are related to leaf, fruit and endocarp traits have been shown to be mostly genetically determined with limited influence by the environment [19, 20].…”

Seed germination ecology and salt stress response in eight Mediterranean populations of Sarcopoterium spinosum (L.) Spach

“…The highest seed masses were detected in the populations from the eastern part of the distribution range of the species. Data from the literature confirm that seed morphology and mean seed/fruit size may vary greatly among populations of a species (Ramakrishnan et al, ), and in some cases also when they are close to each other (Santo et al ). Analyzing the different mean annual precipitation from each area where S. spinosum grows, the high variability detected in the mean mass of fruits of S. spinosum does not seem to depend on the average amount of rainfall.…”