Research | david-schwartz-lab

Research topics

Response to drought stress in Pinus halepensis

Response to drought in Pinus halepensis - We study the mechanisms underlying the impressive growth performance of Pinus halepensis in the Yatir forest, which is located in the semi-arid area of Israel. By investigating xylem anatomy, we showed that differences in torus-margo structure explain differences in resistance to embolism among P. halepensis provenances (publication). We also deciphered the molecular response of P. halepensis to drought stress and revealed certain biological processes that are modified during drought and upon recovery (publication). In addition, we study differences in anatomical, mechanical and physiological parameters among different woody species at three sites along the climatic gradient in Israel.

P. halepensis tracheids

Pinus brutia X P. halepensis hybrids

P. brutia and P. halepensis co-exist in most forests in Israel, all of which are now in the process of natural renewal. We investigate the occurrence and the performance of these natural hybrids in forests along the climatic gradient in order to determine how these hybrids contribute to the successful renewal of the forest.

Yatir forest

Response to insects

We are interested in the parameters determining the differences between susceptible and resistant pine species in response to attack by the aphid Matzucoccus josephy. To this end, we study structural as well as molecular changes in the tissue in response to aphid attack in both P. halepensis (susceptible) and P. brutia (resistant) species at different stages of pine-aphid interactions.

Adult P. halepensis trees infected by M. josephi (photo credit: Alex Protasov)

Growth performance of Cedrus spp.

We study growth performance of Cedrus spp. and of hybrids in planted forests in the northern part of Israel, where we observe high phenotypic variation in mixed Cedrus spp. plantations. Since morphological traits in Cedrus spp. are highly plastic and are influenced by environmental factors, it is difficult to identify species. We have therefore developed the use of nuclear SNP markers for genotyping.

Mixed Cedrus spp. plantation

Vegetative propagation of Pinus spp.

In order to be able to preserve and propagate selective genotypes that are obtained from our various research projects, we are developing a propagation technique based on tissue culture.