20.500.12556/RUL-68633 Seasonal dynamics of phloem formation in Silver fir and Norway spruce as affected by drought The dynamics of phloem growth ring formation in silver fir (Abies alba Mill.) and Norway spruce (Picea abies Karst.) at different sites in Slovenia during the droughty growing season of 2003 was studied. We also determined the timing of cambial activity, xylem and phloem formation, and counted the number of cells in the completed phloem and xylem growth rings. Light microscopy of cross-sections revealed that cambial activity started on the phloem and xylem side simultaneously at all 3 plots. However, prior to this, 1-2 layers of phloem derivatives near the cambium differentiated without previous divisions.The structure of the early phloem was similar in silver fir and Norway spruce. Differences in the number of late phloem cells were found among sites. Phloem growth rings were the widest in Norway spruce growing at the lowland site. In all investigated trees, the cambium produced 5-12 times more xylem cells than phloem ones. In addition, the variability in the number of cells in the 2003 growth ring around the stem circumference of the same tree and among different trees was higher on the xylem side than on the phloem side. Phloem formation is presumably less dependent on environmental factors but is more internally driven than xylem formation. Picea abies Abies alba phloem sieve cells cambial activity cell differentiation light microscopy true false false Interperiodica: Russian Academy of Sciences Angleški jezik Neznan jezik Delo ni kategorizirano 2015-07-10 21:08:57 2015-07-10 21:08:57 2022-08-01 12:52:16 0000-00-00 00:00:00 2008 0 0 Str. 538-543 no. 4 Vol. 55 2008 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 630 1021-4437 10.1134/S102144370804016X 1643401 Gricar-Cufar-RJPP-2800_ABAL_Phloem.pdf Gricar-Cufar-RJPP-2800_ABAL_Phloem.pdf 1 6435A01215176A8E6EC1B4D0FB5CDDEA a2ec712bc9c7b26632a735d572e6e36f23c1fdb62fb36a4e4024eb4a0b10bede 676090e2-a1b3-11eb-a523-00155dcfd717 20.500.12556/rul/752fafc9-157d-4a36-9419-19fa2f3f7cff https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=100824 Biotehniška fakulteta 0 0 0