Location: Subtropical Horticulture ResearchTitle: Selection of Highly Informative Microsatellite Markers to Identify Pollen Donors in 'Hass' Avocado Orchards Author
|Schnell Ii, Raymond|
Submitted to: Plant Molecular Biology Reporter
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/17/2009
Publication Date: 5/27/2009
Citation: Ying, Z., Davenport, T.L., Zhang, T., Schnell Ii, R.J., Tondo, C.L. 2009. Selection of Highly Informative Microsatellite Markers to Identify Pollen Donors in 'Hass' Avocado Orchards. Plant Mol Biol Rep 27:374-380 Interpretive Summary: The need for complementary flowering cultivars in commercial avocado groves has been intensely debated. To date a definitive answer has not been obtained regarding the need for pollen donors. In this study microsatellite markers were evaluated to find the best markers for determining the pollen parents of the fruit from maternal cultivar 'Hass'. Nine cultivars commonly grown in California were studied using 59 microsatellite markers to determine which markers would be the best predictors of paternity for 'Hass' fruit. Four markers were identified that will give greater than 99% probability of correct paternity when the pollen donor pool is limited to the nine southern California cultivars and 'Hass' is the maternal parent. These markers are being used to study the need for polarizer rows in commercial avocado orchards in California and Florida.
Technical Abstract: ‘Hass’ is the most popular avocado (Persea americana Mill.) cultivar in the world. It has been characterized as a crop requiring cross pollination; however, the potential extent of self pollination and the most effective pollen donors (best cross-pollinizing cultivars) have not been determined. In this study, 17 microsatellite, i.e. simple sequence repeat (SSR) markers, were found to be very promising for paternity analysis after 56 markers were screened against ‘Hass’ and nine commonly used pollinizing cultivars grown in southern California: ‘Bacon’, ‘Ettinger’, Fuerte’, ‘Harvest’, ‘LambHass’, ‘Marvel’, ‘Nobel’, ‘SirPrize’, and ‘Zutano’. Four highly informative SSR markers were selected to accurately and unequivocally identify pollen parents of ‘Hass’ fruit from an orchard interplanted with these pollinizing cultivars. Seven thousand nine hundred eighty four Hass’ fruit were analyzed from 2003 to 2006 for their paternity. Overall, the pollen parents of 99.55% of the analyzed fruit could be unequivocally identified with a single multiplex PCR reaction. Only 36 fruit (<0.45%) required a second PCR reaction to reach unequivocal identification of the pollen parents.