Subtropical Horticulture Research Site Logo
ARS Home About Us Helptop nav spacerContact Us En Espanoltop nav spacer
Printable VersionPrintable Version     E-mail this pageE-mail this page
Agricultural Research Service United States Department of Agriculture
Search
  Advanced Search
 
Programs and Projects
Subjects of Investigation
 

Research Project: CONSERVATION, CHARACTERIZATION, AND GENETIC IMPROVEMENT OF SUBTROPICAL AND TROPICAL ORNAMENTAL GERMPLASM

Location: Subtropical Horticulture Research

Title: Ambiguous genetic relationships among coconut (Cocos nucifera L.) cultivars: the effects of outcrossing, sample source and size, and method of analysis.

Authors
item Mauro-Herrera, Margarita -
item Meerow, Alan
item Perera, Lalith -
item Russell, Joanne -
item Schnell Ii, Raymond

Submitted to: Genetic Resources and Crop Evolution
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 22, 2009
Publication Date: July 31, 2009
Citation: Mauro-Herrera, M., Meerow, A.W., Perera, L., Russell, J., Schnell Ii, R.J. 2009. Ambiguous genetic relationships among coconut (Cocos nucifera L.) cultivars: the effects of outcrossing, sample source and size, and method of analysis.. Genetic Resources and Crop Evolution. 57:203-217.

Interpretive Summary: Using 41 DNA genetic markers we show that inferred relationships of coconut varieties from germplasm collections is strongly influenced by undetected hybridization between varieties in the sampled collections, as well by the method used to analyze the data. Therefore, the currently accepted scenario of coconut domestication may be an inaccurate depiction.

Technical Abstract: A prior analysis of eight coconut cultivars with 15 microsatellite (SSR) markers drew unexpected relationships between two of the out-crossing tall cultivars evaluated: ‘Atlantic Tall’ and ‘Panama Tall’. We further investigated the relationships between these eight cultivars by increasing the number of individuals studied (particularly for ‘Atlantic Tall’ and ‘Panama Tall’), by including 28 more molecular markers, and by adding two other cultivars to our analysis. Our results show that five to ten coconut individuals do not represent a dependable sample to withdraw conclusions regarding cultivar/variety relationships, particularly when studying out-crossing genotypes. As suggested in the prior study, a high level of hybridization was observed between the ‘Atlantic Tall’ and ‘Panama Tall’ cultivars. However, at this time we were able to identify distinct groups for each one of these two cultivars. The two clustering methods used (Neighbor Joining, NJ and Unweighted Pair Group Method with Arithmetic mean, UPGMA) produced dendrograms that resolved contrasting cultivar relationships, especially for the ‘Atlantic Tall’ and ‘Panama Tall’ cultivars. We discuss the implications of our results in regard to current scenarios of coconut domestication and future considerations when assessing genetic relationships among different varieties.

   

 
Project Team
Meerow, Alan
Ayala-Silva, Tomas
Reed, Stewart
 
Publications
   Publications
 
Related National Programs
  Water Availability and Water Management (211)
  Plant Genetic Resources, Genomics and Genetic Improvement (301)
 
 
Last Modified: 06/19/2013
ARS Home | USDA.gov | Site Map | Policies and Links 
FOIA | Accessibility Statement | Privacy Policy | Nondiscrimination Statement | Information Quality | USA.gov | White House