Rootstock Influences Changes in Ion Concentrations, Growth, and Photosynthesis of `Hass' Avocado Trees in Response to Salinity
Year: 2002
Type: article
Abstract: Effect of salinity (1.5, 3.0, 4.5, or 6.0 dS·m-1) on growth and physiology of 1-year-old `Hass' avocado (Persea americana Mill.) trees on one of three rootstocks, `Thomas', `Toro Canyon', or `Duke 7', was investigated to determine the relative salinity tolerance of these rootstocks and to determine possible reasons for any observed differences in tolerance. Leaves of trees on `Thomas' rootstock had the highest leaf Na+, Cl-, and necrosis compared to trees on the other two rootstocks. Exposure to salinity resulted in decreased growth of shoots on all rootstocks, but was greatest on `Thomas' and least on `Duke 7'. The oldest leaves on all rootstocks had the highest proportion of leaf necrosis, whereas younger leaves exhibited almost no necrosis. Salinity reduced net CO2 assimilation (A) and chlorophyll concentrations of scion leaves on all rootstocks, but more in older leaves than in younger leaves. Although the effects of salinity on A were greater for trees on `Thomas' on one measurement date, overall, rootstock differences in A were not significant for any leaf age. Differences in response to salinity among rootstocks were noted primarily in morphological traits such as growth and leaf necrosis, rather than physiological traits such as gas-exchange and water relations. Based on overall growth and physiological response to salinity, trees on `Thomas' performed poorest, whereas trees on `Duke 7' exhibited the greatest salt tolerance. The relative tolerance of the various rootstocks appeared to be due primarily to their ability to exclude Na+ and Cl- from the scion.
Authors: Michael V. Mickelbart, Mary Lu Arpaia
Institution: University of California, Riverside
Language: English
Subfield: Plant Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: gold
Estimated APC paid: $3,500
OpenAlex ID: W2136388703