Salsola rubescens Franch. is a wind-pollinated halophytic shrub that produces fruits with red and yellow winged perianths. Germinability of seeds from both fruit types was determined under various light, temperature, and salinity treatments. Red seeds, with and without winged perianths, were heavier than yellow seeds. Germination percentage and germination rate index (speed) were significantly affected by the perianth colour, presence of wings, and temperature and light of incubation and most of their interactions. Germination percentage was greater for yellow-winged seeds than for red-winged seeds. Wing removal significantly enhanced the germination percentage and germination speed in the two types. The presence of wings enhanced germination at lower temperatures, but wing absence enhanced germination at higher temperatures. Wing removal enhanced germination to a greater degree in yellow than in red seeds. There was no light requirement during germination of red-winged seeds, but yellow-winged seeds germinated significantly more in light than in darkness. Red-winged and dewinged seeds were more tolerant to salinity than yellow seeds. Removal of wings significantly increased salinity tolerance for seeds of both wing colours. It is concluded that the showy perianth colours have an ecological role in wind-pollinated plants in regulating dormancy and germination behaviour in the heterogeneous unpredictable hyperarid deserts.Résumé : Le Salsola rubescens Franch., un arbuste halophyte pollinisé par le vent, produit des fruits avec périanthes ailés rouges ou jaunes. Les auteurs ont déterminé le potentiel germinatif des deux types de graines sous différents traitements de lumière, de temperature, et de salinité. Les graines rouges, avec ou sans périanthes ailés, sont plus lourdes comparativement aux graines jaunes. Le pourcentage de germination et l'index du taux de germination (vitesse) sont affectés de façon significative par la couleur du périanthe, la présence des ailes, ainsi que par la température et la lumière d'incubation incluant la plupart de leurs interactions. Le pourcentage de germination est plus grand chez les graines à ailes jaunes comparativement aux graines à ailes rouges. L'ablation des ailes augmente significativement le pourcentage et la vitesse de germination chez les deux types. La présence des ailes augmente la germination aux faibles températures, mais l'absence des ailes augmente la germination aux températures plus élevées. L'ablation des ailes augmente la germination à un plus fort degré chez les graines jaunes que chez les rouges. On n'observe pas de besoin en lumière au cours de la germination des graines à ailes rouges, mais les graines à ailes jaunes germent significativement plus à la lumière qu'à l'obscurité. Les graines rouges et les graines privées de leurs ailes s'avèrent plus tolérantes à la salinité que les graines jaunes. L'ablation des ailes augmente significativement la tolérance à la salinité chez les graines aux ailes des deux couleurs. On conclut que les couleurs voyantes des...

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The effects of maternal salinity and light incubation on the salinity tolerance of the facultative halophyte Anabasis setifera during their germination stages were assessed. Seeds were collected from non-saline habitats in Egypt and saline habitats in the United Arab Emirates (UAE). The seeds of the two populations were germinated in 0, 100, 200, 400, 600 and 800 mM NaCl, and incubated at 25°C/15°C in both 12-h light and 12-h darkness regimes and continuous darkness. Significantly more seeds germinated in the Egyptian population than in the UAE population. Salinity tolerance was significantly greater with the Egyptian population than with the UAE population, especially under the conditions of higher salinities. The difference in salinity tolerance between the seeds of two populations was attributed to their seed mass. In addition, germination was significantly faster for the Egyptian population than for the UAE population. Most of the saline treated seeds were able to recover their germination when transferred to distilled water, but this depended on their maternal salinity and light incubation. Recovery from higher salinities was significantly better for the seeds under darkness than for those under light in the UAE population, but the reverse was true for the seeds in the Egyptian population. The higher salinity tolerance for the A. setifera seeds from the non-saline Egyptian population and the lower salinity tolerance for the seeds from the saline UAE population cannot explain their natural distribution. Further studies about other possible roles, such as levels of different promoting and inhibiting phytohormones, are needed to understand the importance of salinity as an environmentally induced maternal effect.

The Arabian Peninsula is known to have a comprehensive and rich endowment of unique and genetically diverse plant genetic resources. Analysis and conservation of biological diversity is a crucial issue to the whole Arabian Peninsula. The rapid and accurate delimitation and identification of a species is crucial to genetic diversity analysis and the first critical step in the assessment of distribution, population abundance and threats related to a particular target species. During the last two decades, classical strategies of evaluating genetic variability, such as morphology and physiology, have been greatly complemented by phylogenetic, taxonomic, genetic diversity and breeding research molecular studies. At present, initiatives are taking place around the world to generate DNA barcode libraries for vascular plant flora and to make these data available in order to better understand, conserve and utilize biodiversity. The number of herbarium collection-based plant evolutionary genetics and genomics studies being conducted has been increasing worldwide. The herbaria provide a rich resource of already preserved and identified material, and these as well as freshly collected samples from the wild can be used for creating a reference DNA barcode library for the vascular plant flora of a region. This review discusses the main molecular and genomic techniques used in plant identification and biodiversity analysis. Hence, we highlight studies emphasizing various molecular techniques undertaken during the last 10 years to study the plant biodiversity of the Arabian Peninsula. Special emphasis on the role of DNA barcoding as a powerful tool for plant biodiversity analysis is provided, along with the crucial role of herbaria in creating a DNA barcode library.

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