Comparing ‘Iriet’ and ‘Ettinger’ avocado cultivars as pollinators of ‘Hass’ using SNPs for paternal identification

Abstract

Avocado (Persea americana M.) exhibits a two-type ‘synchronous dichogamy’ form of flowering that promotes outcrossing. In ‘type A,’ the flower opens in the female phase from morning till noon, then closes and re-opens on the afternoon of the following day in the male phase. In ‘type B,’ the flower opens in the female form on the afternoon of the first day, closes at the end of the day, and re-opens in the male form on the following morning. In both types, the female and male forms may overlap and self-fertilize. Planting an A type and B type cultivar adjacently to each other increases yield in most cases. ‘Hass’ (A type) is the most favorable avocado cultivar worldwide, however, the cultivar that serves as its pollinator varies between regions and countries. In Israel, for more than 30 years, the ‘Ettinger’ cultivar (B type, a seedling of ‘Fuerte’ selected in Israel) is its only pollinator, hence, adding another pollinator for ‘Hass’ should be beneficial. ‘Iriet’ (B type) is an Israeli-bred cultivar and its fruit has a ‘Hass’-like appearance (a marked change in color from green when not ripe to black at full ripe).For accurate comparison between ‘Iriet’ and ‘Ettinger’ as a pollinator of ‘Hass,’ an orchard with the two pollinators was planted and a SNP analysis was developed for the identification of the paternal parents of the ‘Hass’ fruits. In addition, the flowering phenology and honeybee visits were determined. The results suggest that ‘Iriet’ is a good pollinator for ‘Hass’ and could be added alongside ‘Ettinger’ as a pollen donor for ‘Hass’.