Oz Barazani and Jotham Ziffer-Berger
Sivan Golan, Yoni Waitz, Jotham Ziffer-Berger, Michal Barzilai, Nir Hanin, Zalmen Henkin and Oz Barazani
Germination behavior of the widespread southeastern Mediterranean shrub Sarcopoterium spinosum was conducted to assess its respond to post-fire cues. Germination experiments were conducted on 10 populations along a rainfall gradient – from productive, fuel-rich and fire-prone mesic Mediterranean populations, as well as from those in arid and fuel-poor environments. Our results indicate that post-fire cues induced germination of S. spinosum only among populations that originated from sites that are prone to wild fires. As wild-fires in this region occur mainly during the long dry season, but rarely ignited by natural factors, the adaptation to human made fires in natural populations of the southeastern Mediterranean environments is discussed.
Jotham Ziffer-Berger, Alexandra Keren-Keiserman, Adi Doron-Faigenboim, Klaus Mummenhoff and Oz Barazani
Molecular tools provide new insights into phylogenetic relationships of plant species, and by relating phylogenetic groups to their geographical distribution, we can cast light upon the evolution history of plant clades. In the current study, we evaluated the phylogenetic position of the Sinai endemic Brassica deserti (Brassicaceae), later renamed as Erucastrum deserti, based on morphological data and 5.8S rDNA and ITS (Internal Transcribed Spacer) regions. Our results indicate that B. deserti belongs to an East-Mediterranean – Saharo Arabian clade and was not assigned to the core Brassica and Erucastrum clades, respectively, which evolved in the West Mediterranean area. We tentatively conclude that Brassica deserti evolved independently of core Brassica and Erucastrum.
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.