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Ori Fragman-Sapir and Nikolai Friesen

ABSTRACT

Allium palaestinum, a long-forgotten taxon of arid Israel and Jordan, is re-described here. The new description is based on Kolmann's work in 1971 and on living plants and fresh herbarium specimens. Independence of the species is confirmed not only by differing morphological and ecological features of the nearest related Allium species, but also by molecular methods. Hence, the species is no longer treated within Allium neapolitanum. Discussion on phylo-geography, distribution, conservation status and habitat is provided.

Rivka Hadas, Rina Kamenetsky and Ori Fragman-Sapir

A complementary approach of ex-situ conservation of native Israeli geophytes with horticultural potential is presented. Sixty-eight species with ornamental traits were selected out of the 234 geophytes of Israeli flora to be collected and preserved by the Israel Plant Gene Bank (IGB) and the Jerusalem Botanical Gardens (JBG). The target list is categorized into three types of potential horticultural products: garden plants, cut flowers, and flowering pot plants. In addition to their attractiveness as ornamental plants, many of the Israeli wild geophytes are potentially self-maintained crops that can be utilized in water-saving horticultural practices. The new ornamental species might also provide extra value in international markets, as well as for gardening and landscape development in the Mediterranean and semiarid regions. Selected species with ornamental potential are discussed and detailed in five test cases.

Jaime Kigel, Irit Konsens, Naomi Rosen, Gur Rotem, Ari Kon and Ori Fragman-Sapir

There is growing evidence for rapid adaptive evolution in response to climate change, including phenological transitions such as earlier flowering with climate warming. The consequences of these evolutionary changes for population dynamics and shifts in species ranges remain, however, quite unexplored. Here, we propose that inter-population differences in patterns of flowering across geographic precipitation gradients can be considered a proxy for changes in flowering time due to variation in rainfall resulting from climate change. To this end, we analyze trends of variation in flowering time across rainfall gradients in the eastern Mediterranean region in three main plant life-forms present in the local vegetation: winter annuals, geophytes, and perennial grasses. These life-forms cope with the hot and dry summer via a drought escape strategy. The analysis is based on published and unpublished data from common-garden experiments in which plants from populations sampled along rainfall gradients were grown under similar conditions, thus allowing detection of genetic differences in flowering time along the gradient. The data clearly indicate that decreasing rainfall across a Mediterranean-desert transect is associated with earlier flowering in winter annual species. In contrast, the limited available data shows no consistent trend of change in flowering time with decreasing rainfall in geophytes and perennial grasses. The phenological shift to early flowering in winter annuals coping with terminal drought appears to be a widespread method for adaptation to arid environments by stress avoidance, diminishing the risk of early death before seed production. However, changes in flowering time associated with the reduction in precipitation predicted by climate change models are relatively small, suggesting that additional traits are involved in the adaptation to increasing aridity. The hypothesis that low water availability is an environmental signal inducing earlier flowering of annual plants under drought conditions is not supported by experimental data.

Sofia Shevtsov, Omer Murik, Hagit Zer, Ofir Weinstein, Nir Keren, Ori Fragman-Sapir and Oren Ostersetzer-Biran

The sparsely distributed Limodorum abortivum is a European-Mediterranean orchid species, which grows on decomposing plant material. Although some chlorophyll-pigmentation is observed in the degenerated scales-shaped leaf and stems regions of the plant, its photosynthetic capacity is assumed to be insufficient to support the full energy requirements of an adult plant. In Israel, L. abortivum shows a patchy distribution patterns in the Galilee, Golan, Carmel and Judean regions. To gain more insights into the physiology and photosynthetic activity of L. abortivum, we analyzed the organellar morphologies, photosynthetic activities the chloroplast-DNA sequence by Illumina-HTS. Microscopic analyses indicated to the presence of mature chloroplasts with well-organized grana-thylakoids in the leaves and stems of L. abortivum. However, the numbers of chloroplasts per cell and the grana ultrastructure density within the organelles were notably lower than those of model plant species and fully photosynthetically-active orchids. The cpDNA of L. abortivum (154,954 bp) encodes 60 proteins, 34 tRNAs and 4 rRNAs. The coding-regions of 24 genes are interrupted by 26 group-II intron-sequences. While many genes related to photosynthesis (RuBisCo, PSI, PSII and cytochrome b 6 /f subunits) have remained intact in the cpDNA, the majority of the NADH-dehydrogenase (ndh) subunits were either lost or became nonfunctional (i.e. pseudogenized). In agreement with previous reports, the photosynthetic-rates of adult Limodorum plants were found to be very low, further indicating that carbon-assimilation activity is insufficient to support the energy requirements of an adult plant, and may suggest that L. abortivum have adopted nutritional strategies similar to that of mycoheterotrophic orchid species.