TANSCRIPTIONAL AND PHYSIOLOGICAL ANALYSIS FOLLOWING DROUGHT STRESS IN TWO POPULUS PARENTS FROM A MAPPING PEDIGREE - FIRST STEP FOR QTL-MICROARRAY ANALYSIS OF CANDIDATE GENES.

¹ School of Biological Sciences, University of Southampton, Bassett Crescent East, SO17 9PX, UK

² UPSC, Umeaa University, 901 87 Umeaa, Sweden

³ KTH, AlbaNova University Centre, 10691, Stockholm, Sweden

Drought stress remains one of the most important limitations to forest productivity, globally. Physiological responses to drought have often been characterised and it is known that both leaf growth and stomatal response to drought may be rapid. Here we have exposed two contrasting poplar species to drought stress, P. trichocarpa and P. deltoides. In addition, these are the parents of the mapping family, family 331, for which considerable data on growth, development and adaptation are already available along with defined QTL. The aim of the research described here was to link the physiological analysis on response to drought to transcript profiles gained using the Swedish Populus microarray. We have defined 20 gene products that appear sensitive to drought and also a number of gene products that differ between species. These are being used in an on-going analsysis to elucidate and map candidate genes in the F2 progeny.