Evaluation of Own-Rooted vs. Budded Prune ( Prunus DomesticaL.) Seedling Genotypes

Abstract

Growth characteristics of Prunus domesticaseedlings on their own roots were compared to the same genotypes budgrafted to vigorous, 1 year-old, commercial ‘Marianna 2624’ rootstock. Mean shoot growth of budded genotypes on the rootstock was substantially greater than on their own roots. Growth of seedling genotypes on their own roots was only moderately correlated with growth on the rootstock. The 10 tallest seedling genotypes generally had larger, more active (higher rates of leaf photosynthesis and leaf conductance to water vapor) leaves than the 10 shortest genotypes both on their own roots and as scions on the rootstock. There were no consistent, statistically significant differences in midday stem water potential between tall and short genotypes but short genotypes on their own roots had significantly lower midday stem water potentials than their counterparts growing as scions. Among the entire population of 54 genotypes studied, the leaves of scion grown plants had significantly higher mean leaf concentrations nitrogen and potassium, but no consistent differences in phosphorus. Growth of genotypes as seedlings was positively related to leaf nitrogen concentration but negatively related to leaf potassium concentration. There was no relationship between leaf nitrogen or potassium concentration of the same genotypes grown as scions.