Tissue Elastic Properties of a Mesic Forest Hawaiian Dubautia Species with 13 Pairs of Chromosomes

Abstract

Dubautia reticulata grows in a mesic forest habitat in Hawaii and has 13 pairs of chromosomes: The tissue elastic properties of this species are intermediate relative to those of the dry scrub , 13-paired D. menziesii and the mesic forest , 14-paired D. knudsenii. The tissue elastic modulus near full hydration , for example, is 3.5 MPa in D. menziesii, 6.1 MPa in D. reticulata, and 18.2 MPa in D. knudsenii. As a result of its intermediate tissue elastic properties, D. reticulata exhibits an intermediate capacity for maintaining high turgor pressures as tissue water content decreases . These result s imply that tissue elastic properties are significantly associated both with the habitat in which a Dubautia species grows and with its diploid chromosome number. The latter association is presumably indirect, with the difference in chromosome number serving as a marker for other significant genomic differences.