Shifts in xylem vessel diameter and embolisms in grafted apple trees of differing rootstock growth potential in response to drought |
| |
Authors: | Taryn L Bauerle Michela Centinari William L Bauerle |
| |
Institution: | (1) Department of Horticulture, Cornell University, 134A Plant Science Building, Ithaca, NY 14853, USA;(2) Department of Horticulture & Landscape Architecture, Colorado State University, 213 Shepardson Building, 1173 Campus Delivery, Fort Collins, CO 80523, USA |
| |
Abstract: | We investigated responses of plant growth rate, hydraulic resistance, and xylem cavitation in scion-rootstock-combinations
of Malus domestica L. cv. Honeycrisp scions grafted onto a high-shoot vigor (HSV) rootstock, (semi-dwarfing Malling111), or onto a low-shoot
vigor (LSV) rootstock, (dwarfing Budagovsky 9), in response to substrate moisture limitation. Adjustments in xylem vessel
diameter and frequency were related to hydraulic resistance measurements for high- versus low- vigor apple trees. We observed
a greater tolerance to water deficit in the high-shoot compared to the low-shoot vigor plants under water deficit as evidenced
by increased growth in several plant organs, and greater scion anatomical response to limited water availability with ca.
25% increased vessel frequency and ca. 28% narrower current season xylem ring width. Whereas water limitation resulted in
greater graft union hydraulic resistance of high-shoot vigor trees, the opposite was true when water was not limiting. The
graft union of the low-shoot vigor rootstock exhibited higher hydraulic resistance under well-watered conditions. Scions of
high-shoot vigor rootstocks had fewer embolisms at low plant water status compared to scions of low-shoot vigor rootstocks,
presumably as a result of large differences in xylem vessel diameter. Our results demonstrated that anatomical differences
were related to shifts in hydraulic conductivity and cavitation events, a direct result of grafting, under limited soil water. |
| |
Keywords: | |
本文献已被 PubMed SpringerLink 等数据库收录! |
|