Effect of supplementary pollination by different pollinizers on fruit set and nut physicochemical traits of ‘Supernova’, a self-compatible almond

Abstract

Introduction. Most commercial almonds are self-incompatible and growing these cultivars would increase orchard management costs. Self-compatible almond cultivar cultivation seems to be the solution to increase the yield and reduce the production costs. Materials and methods. In this study, the self–compatible almond cultivar Supernova was used as a seed parent and hand pollinated by the pollen of ‘Shahrood 21’, ‘Shahrood 12’, ‘Fra Giulio Grande’, ‘4–10’, ‘11–5’, and ‘Supernova’ itself. Also, two pollination methods were used, using ‘Supernova’ non–emasculated vs. emasculated flowers. Pollen tube growth of these pollinizers was studied by fluorescent microscopy at different times from flower samples harvested at 24, 48, 72, 96 and 120 h after hand pollination. The composition of fatty acids and the main characteristics of the fruit in the seed parent ‘Supernova’ were recorded after fruit harvest. Results and discussion . Although all pollens of the used pollinizers were compatible on ‘Supernova’ and had satisfied fruit set, significant differences were observed among pollinizers in stages 2 and 3. The highest fruit set was achieved when ‘Shahrood 21’ pollen was used, while the lowest fruit setting was recorded in ‘Supernova’ by self-pollination. Microscopic observation at 120 h after pollination revealed that pollen tubes of all pollinizers reached the ovary of ‘Supernova’. In this study, fatty acid content was varied with oleic acid between 70.11 to 77.76%, linoleic acid from 4.0% to 5.5%, palmitic acid from 6.17 to 6.73%, stearic acid from 1.50 to 1.91%, palmitoleic acid from 0.40% to 0.47%, arachidic acid from 0.1 to 0.4%, gadoleic acid from 0.05 % to 0.06% and total oil content was between 50.25 to 51.59%. Conclusion . This experiment revealed that different pollen sources had a significant effect on fruit setting, but not in the oil content and fatty acid composition of the seed parent kernels.