Pine genome size diversity and water relations

Abstract

Pine genome size diversity and water relations, -Physiol, Plant,. Important functions of water relations are considered to be related to genome size diversity in gymnosperms. We investigated relationships among genome size, dimensional characteristics of conductive cells, and water relations parameters by using young seedlings of six Pinus species. Xylem hydraulic conductivity was not correlated with genome size and dimensional characteristics of conductive cells, but the water potential at the turgor loss point was, Pinus species with large genome sizes had thick cell walls and small ratios of lumen radii to cell wall thickness in their conductive cells, and those spcies lost their turgor to tissue dehydration at low water potentials. The characteristics obsen'ed in the present study may contribute to pine drought tolerance.

Genome size microscale divergence of Cyclamen persicum in Evolution Canyon, Israel

“…Notably, the trend of higher genome size at the AS rather than on the ES was claimed also in H. spontaneum in EC, but no raw data were published [5]. This conclusion is in line with suggestions that increased tolerance to drought (and to another stresses such a frost) is associated with larger genome size in plants [4,5,35,37,38]. It should be noted that other ecogeographically correlated intraspecific variability in genome size was documented apart from Ceratonia siliqua [4]; for example, between genome size and altitude at the local geographic scale in Zea mays [39] and Dactylis glomerata [40,41].…”

“…However, the Fit data-fusion test on Spearman correlations between 2C-values in four species (C. persicum, the carob tree Ceratonia siliqua, trifoil, Lotus peregrinus and the sawthoothed grain beetle, Oryzaephilus surinamensis) studied so far at EC and the ranking of stations according to their increasing aridity indicate a possibility that genome increases with the level of drought at EC, in line with earlier predictions [4,5,35,37,38]. The test results could be regarded as significant if the significance threshold released to α = 0. four tested species showed the same interslope trend in correlation between genome size and ranking of stations according to increasing drought, i.e., higher genome size at the AS than the ES.…”

Evolution of Genome Size in Pines (Pinus) and Its Life-History Correlates: Supertree Analyses

“…However, we found some support for the results of Wakamiya et al (1993Wakamiya et al ( , 1996 when we analyzed our data using PICS (Tables 3A, 4). A significant negative trend was seen in phylogenetically corrected (but not Bonferroni-corrected) analyses in subgenus Strobus in 11% (at the P Յ 0.05 level) or 62% (at the P Յ 0.10 level) of the tree topologies (Table 3A).…”

“…Annual grasses (but not perennial grasses) with larger genomes were found to have greater responses to CO 2 enrichment (Jasienski and Bazzaz 1995). Wakamiya et al (1996) found that in pines genome size was negatively correlated with the water potential at turgor loss and with cell wall characteristics. Relative growth rates have also been negatively correlated with nuclear DNA content in fast-growing versus slow-growing Acacia species (Mukherjee and Sharma 1990), nuclear DNA content in Poa annua populations (Mowforth and Grime 1989), and genome size in six pine species (Wakamiya et al 1996).…”

“…Wakamiya et al (1996) found that in pines genome size was negatively correlated with the water potential at turgor loss and with cell wall characteristics. Relative growth rates have also been negatively correlated with nuclear DNA content in fast-growing versus slow-growing Acacia species (Mukherjee and Sharma 1990), nuclear DNA content in Poa annua populations (Mowforth and Grime 1989), and genome size in six pine species (Wakamiya et al 1996). Again, most of the species examined in these studies are diploid, so the authors did not have to make a clear distinction between the effects of genome size and those of nuclear DNA content.…”