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We investigated the dimorphic perianth colour of Salsola vermiculata and its association with seed germination percentage, interactions with temperature, light, salinity and recovery from prior salinity exposure. Seeds with and without pink and yellow perianth were incubated at three thermal regimes, two photoperiods, and five salinity levels. Germination recovery after salinity exposure was observed on seeds that failed to germinate during the salinity study. The germination percentage and rate were significantly related to the perianth colour, the presence of perianth wings, thermal regimes and photoperiod. The presence of a perianth wing significantly reduced germination percentage and germination rate in both the pink and the yellow morph, but the yellow morph exhibited a higher germination percentage. Perianth wing removal increased germination in saline conditions. With the perianth removed, germination recovery was higher for the pink morph than for the yellow one. We suggest that by providing two different strategies for balancing germination with dormancy during favourable conditions, the presence of two morphs makes S. vermiculata more successful in highly unpredictable desert environments. [ABSTRACT FROM AUTHOR]

Bienertia cycloptera (Chenopodiaceae) produces two types of leaf foliage colour (reddish and yellowish). In order to determine the role of leaf colour variation in regulating the germination characteristics and salinity tolerance during germination, a study was conducted on seeds collected from plants of both colours. Seeds with and without pulp were germinated under two illumination conditions (12-h light photoperiod and continuous dark), three alternating temperature regimes (15/25°C, 20/30°C and 25/35°C), and several salinity levels at 20/30°C. Germination percentage was significantly higher for seeds without pulp as compared to the seeds with pulp. The response of B. cycloptera seeds to salinity depended on the leaf colour. Thus, the seeds collected from reddish coloured plants were able to tolerate higher salinity compared to those of yellowish coloured plant. The germination recovery results indicate that the seeds from both coloured plants could remain viable in saline condition and they will be able to germinate once the salinity level are decreased by rain. The production of different foliage colours by B. cycloptera seems to be an adaptative strategy which increases the possibility for establishment in unpredictable environments by producing seeds with different germination requirements and salinity tolerance. [ABSTRACT FROM AUTHOR]