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.

Oz Barazani, Nir Hanin, Prabodh Kumar Bajpai, Yoni Waitz, Michal Barzilai, Alexandra Keren-Keiserman, Tomer Faraj, Einav Mayzlish-Gati, Erik Westberg and Jotham Ziffer-Berger

The winter annuals Brassica tournefortii and Raphanus raphanistrum (Brassicaceae) share similar habitats and life-history traits, but differ in their reproduction system (self-compatibility vs. self-incompatibility, respectively). The two phylogenetically close species offer means to assess the effect of reproductive biology on genetic diversity between and within populations. In general, genetic diversity between populations of B. tournefortii was higher than that found between populations of R. raphanistrum, while higher genetic diversity indices were evident within populations of R. raphanistrum. In addition, the results of pairwise genetic distances indicated that the genetic distances between populations can be associated to the species’ reproductive biology and not to the population’s distribution pattern. We discuss whether knowledge of reproductive and habitat characteristics can be used to predict genetic diversity when planning sampling scheme for ex situ conservation.