ABOUT US
The main activity of the Israel Plant Gene Bank is the conservation of the genetic diversity of local plant genetic resources and crop wild relatives. Our research in the lab, at the gene bank, is focused on several eco-genomic and evolutionary studies in local species. Our research addresses broad aspects of genetic sub-clustering as a marker for within- and between diverse plant populations.
RESEARCH PROJECTS
Raphanus (Brassicaceae) comprises three species, including wild and cultivated radishes. We conduct an evolutionary-ecological study to understand the significance of differences in fruit structure of two allopatric and closely related Raphanus species as adaptive traits appropriate to their specific habitats.The interdisciplinary approach combines taxonomy, molecular systematics, population genetics, seed biology and ecology to understand environmentally-driven evolutionary processes in fruit evolution and dispersal mechanisms. This project thus aims to provide fundamentally novel, comprehensive and increasingly predictive insights on inter-species variation.
Fruit evolution and adaptation to Mediterranean habitats in Raphanus
Ecotypic differentiation in populations of Eruca sativa
Exploring the history of olive tree cultivation in Israel
Populations of Eruca sativa (Brassicaceae) in Israel, originating from a Mediterranean and a desert habitats differ in several floral and defense phenotypic traits. Defense against herbivory in plants of the Mediterranean population is attributed to glucosinolates (GS) and their default breakdown products isothiocyanates (ITCs). In plants of the desert population, GS breakdown products are directed to simple nitriles and defense is associated to induced activity of proteinase inhibitor (PI), flavonoid synthesis and sclerophylly. In this research study we investigate whether defense strategies in populations of E. sativa evolved in response to different herbivore pressures: Where generalists predominate, ITCs provide an efficient defense against herbivory, whereas, where specialists predominate, directing GS to simple nitriles at the expense of ITCs reduces oviposition, and PI reduces larval survival. Taking an interdisciplinary approach, this project aims at revealing the ecological consequences of differentiation to two defense strategies and the accompanied floral traits in populations of E. sativa.
Raphanus raphanistrum
Raphanus pugioniformis
The seeds in Raphanus are enclosed in indehiscent lignified fruits. After detachment from the maternal plant, R. raphanistrum fruits usually break into several one-seeded light-weight dispersal units, whereas the relatively long and heavy fruits of R. pugioniformis, which, typically contain four to six seeds, abscise completely and remain intact.
Plants of E. sativa from desert (left) and Mediterranean (right), representing variation in flower color.
As we found higher abundance of specialist moth at the desert conspecific habitat (below) we investigate whether defense
and floral traits evolved differently as a result of biotic selection agents, in environments dominated by specialist or generalist insects.
Desert conspecific habitat
Mediterranean plant community
The olive tree is strongly associated with the biblical and modern heritage of the people of Israel. In the last 10 years, we have studied genetic variation among 300 old olive trees in the Eastern Mediterranean. Using molecular markers, we demonstrated ancient selection and clonal diversity among rootstocks and scions of grafted trees, and the potential contribution of grafting on selected rootstocks. Using co-dominant markers, we classified naturally growing trees in Israel as feral olives or as Olea europaea subsp. europaea var. sylvestris.
Currently we apply genomic tools in order to extend our understanding of olive tree evolution under the influence of humans in the southeast Mediterranean region, the primary center of olive domestication, into earliest cultivation history.
Collaborators:
Dr. Jotham Ziffer Berger, Levinsky College, Israel
Prof. Klaus Mummenhoff, University of Osnabrueck, Germany
Collaborator:
Prof. Sharoni Shafir, the Hebrew University, Israel
Collaborator:
Dr. Arnon Dag, Agricultural Research Organization, Israel