TY - JOUR
T1 - Shifts in xylem vessel diameter and embolisms in grafted apple trees of differing rootstock growth potential in response to drought
AU - Bauerle, Taryn L.
AU - Centinari, Michela
AU - Bauerle, William L.
N1 - Funding Information:
Acknowledgments We thank, S. Cummins for plant material and grafting services; V. Pagay, B. Emmett, A. Paya, M. Smith, and M. Goebel for their help with plant harvesting and hydraulic resistance measurements; M. Tyree for advice and discussions on hydraulic resistance methodology; M. Goffinet for advice on microtechnique; C. Soudant-Daugherty for Cryo-SEM technique; M. van Iersel, and J. Sparks for the use of high pressure flow meter and gas exchange equipment; and three anonymous reviewers for improvement of this publication. The investigation was supported by the New York State Agriculture Experiment Station.
PY - 2011/11
Y1 - 2011/11
N2 - 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.
AB - 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.
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U2 - 10.1007/s00425-011-1460-6
DO - 10.1007/s00425-011-1460-6
M3 - Article
C2 - 21710199
AN - SCOPUS:80255132772
SN - 0032-0935
VL - 234
SP - 1045
EP - 1054
JO - Planta
JF - Planta
IS - 5
ER -