Abstract
Rootstocks which restrict uptake of toxic elements, such as Na, Cl, and boron (B), may increase resistance of grafted trees to salt and B stresses. The objectives of this study were to evaluate i) growth, ion uptake, and membrane stability of rootstacks exposed to high salinity, II) growth and ion uptake of pistachio on three rootstocks, and iii) growth, B uptake, and carbohydrate status of B-treated seedlings. Seedlings of three Pistacia spp. rootstocks in outdoor lysimeters (P. atlantica, P. terebinthus, and P. alantica x integerrima) were irrigated with saline solutions having ionic composition similar to the Rio Grande River for two seasons. Average stem and root growth decreased at soil solution salinity of 13.8 dS m⁻¹ (8.7 dS m⁻¹ in the saturation extract). Leaf Na concentrations increased above 128 mew Na liter⁻¹ in soil solution. With higher salinity, a selection of P. terebinthus contained the highest Na concentration in leaves and lowest in roots. Excised roots of this genotype were the most sensitive to the saline solutions, measured as leakage of ultraviolet-absorbing solutes. Leakage of all species occurred above 125 mM Na and increased with Na/Ca ratio. Solute leakage tests may aid rootstock selection for saline areas. In a field-trial, growth of P. vera cv. Kerman was highest on P. atlantica x integerrima after one season, but after two years, no differences between rootstocks occurred. Concentrations of Na and Cl in scion leaves were largely unaffected by these rootstocks. Greenhouse experiments showed B had little effect on growth of rootstock seedlings after one year exposure up to 52.9 mg B liter⁻¹ in the soil extract. Boron uptake increased with B application, and was higher in P. terebinthus than P. atlantica. Application of B increased leaf sugars and root starch contents, and decreased root glucose levels in pistachio seedlings. This may suggest a supply-induced limitation of carbohydrates to roots by B-affected leaves. This study did not reveal a more salt- or B-resistant Pistacia spp. rootstock. However, results suggest pistachio can serve as an alternative crop in far west Texas areas afflicted by these costraints.
Picchioni, Geno Anthony (1989). Growth, ion uptake, and some metabolic processes of Pistacia spp. affected by salinity and boron. Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -1109041.