Absorption and accumulation of chloride ions by pecan (Carya illinoensis Koch) seedling rootstocks

Abstract

The affects [sic] of absorption and accumulation of Cl by pecan (Carya illinoensis Koch) seedlings were investigated. Field studies were conducted to determine the Cl accumulation characteristics of pecan seedlings of known parentage, to determine the most effective leaf sampling procedures, and to determine the effect of various irrigation bed-designs on Cl uptake. Greenhouse studies were conducted to determine Cl absorption and accumulation characteristics of pecan rootstocks and to determine the effect of simulated rain fall on Cl content of pecan leaves. Absorption and accumulation of radioactive ³⁶Cl from labeled nutrient culture solutions was determined in growth chamber studies. Laboratory research involved preparation and analytical methods for determination of leaf Cl content. Each of the greenhouse, field, and growth chamber experiments demonstrated the extreme heterozygosity of the pecan. Wide ranges in absorption and accumulation of Cl and exhibition of Cl toxicity symptoms indicated that even among seedlings of the same parentage, predictable patterns were scarce. Exhibition of toxicity symptoms was found to be unreliable as an indicator of Cl accumulation characteristics. Analysis of leaves for Zn, Fe, Mn, and Cl, and measurement of growth indicated the possibility of selection of multipurpose rootstocks. Seedlings exhibiting low leaf Cl accumulation and enhanced Zn accumulation were selected. The accumulation patterns indicated by both radioautograph and field leaf sampling studies indicated larger Cl contents in older leaves. Suggested standard sampling techniques and leaf Cl analysis are presented. Comparison of ion accumulation by individual seedlings of reciprocal parentage crosses suggests the existence of considerable cytoplasmic influences on inheritance.