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United States Department of Agriculture

Agricultural Research Service

Title: Genetic Fingerprints for Individually Quick Frozen 'Marion' Whole Berries and Puree

Author
item Bassil, Nahla

Submitted to: Oregon Raspberry and Blackberry Commission Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: December 10, 2007
Publication Date: N/A

Interpretive Summary: A forensic-type approach was proposed to identify ‘Marion’ type blackberry from Individually Quick Frozen (IQF) whole berries and puree using DNA-based simple sequence repeat (SSR) markers. This approach is useful for quality control and to detect contamination from other berry products. A reliable source of IQF whole berries generously provided us with IQF ‘Marion’ and ‘Kotata’ berries. We also received ‘Marion’ concentrate from a commercial Oregon source. Fresh leaves and fresh berries of these two cultivars were obtained from Chad Finn. Out of two DNA extraction protocols tested, the Qiagen DNeasy mini kit generated good quality DNA from the five DNA samples used in each cultivar: leaves, receptacle from fresh berries, drupelets from fresh berries, receptacle from IQF berries and drupelets from IQF berries. Out of 26 SSRs tested in ‘Marion’ and ‘Kotata’, ten were polymorphic and were further used to identify ‘Marion’ and ‘Kotata’ tissues. Based on initial SSR analysis, the genetic profiles of ‘Kotata’ leaves and berry tissue was identical irrespective of its fresh or frozen status. However, the genetic profile of frozen ‘Marion’ berries was different from that of leaves and fresh berries of ‘Marion’. DNA was then separately extracted from 3 individual berries (receptacle and drupelets) from the IQF ‘Marion’ berries bag. The genetic profile of two out of the three berries was identical to ‘Kotata’ while the remaining berry generated a ‘Marion’ fingerprint, thus indicating that the ‘Marion’ berries bag contained a mix of ‘Kotata’ and ‘Marion’ berries. IQF berries can be identified using SSR markers. However, the DNA of ‘Marion’ concentrate was difficult to amplify and its quality will vary depending on the process by which the concentrate is generated..

Technical Abstract: A forensic-type approach was proposed to identify ‘Marion’ type blackberry from Individually Quick Frozen (IQF) whole berries and puree using DNA-based simple sequence repeat (SSR) markers. This approach is useful for quality control and to detect contamination from other berry products. A reliable source of IQF whole berries generously provided us with IQF ‘Marion’ and ‘Kotata’ berries. We also received ‘Marion’ concentrate from a commercial Oregon source. Fresh leaves and fresh berries of these two cultivars were obtained from Chad Finn. Out of two DNA extraction protocols tested, the Qiagen DNeasy mini kit generated good quality DNA from the five DNA samples used in each cultivar: leaves, receptacle from fresh berries, drupelets from fresh berries, receptacle from IQF berries and drupelets from IQF berries. Out of 26 SSRs tested in ‘Marion’ and ‘Kotata’, ten were polymorphic and were further used to identify ‘Marion’ and ‘Kotata’ tissues. Based on initial SSR analysis, the genetic profiles of ‘Kotata’ leaves and berry tissue was identical irrespective of its fresh or frozen status. However, the genetic profile of frozen ‘Marion’ berries was different from that of leaves and fresh berries of ‘Marion’. DNA was then separately extracted from 3 individual berries (receptacle and drupelets) from the IQF ‘Marion’ berries bag. The genetic profile of two out of the three berries was identical to ‘Kotata’ while the remaining berry generated a ‘Marion’ fingerprint, thus indicating that the ‘Marion’ berries bag contained a mix of ‘Kotata’ and ‘Marion’ berries. IQF berries can be identified using SSR markers. However, the DNA of ‘Marion’ concentrate was difficult to amplify and its quality will vary depending on the process by which the concentrate is generated.

Last Modified: 11/23/2014
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