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TASSEL - Trait Analysis by aSSociation, Evolution and Linkage

TASSEL is a software package used to evaluate traits associations, evolutionary

patterns, and linkage disequilibrium. Strengths of this software include:

1. The opportunity for a number of new and powerful statistical approaches to association mapping such as a General Linear Model (GLM) and Mixed Linear Model (MLM). MLM is an implementation of the technique which our recently published Nature Genetics paper - Unified Mixed-Model Method for Association Mapping - which reduces Type I error in association mapping with complex pedigrees, families, founding effects and population structure.

2. An ability to handle a wide range of indels (insertion & deletions). Most software ignore this type of polymorphism; however, in some species (like maize), this is the most common type of polymorphism.


Read more at:

Bradbury PJ, Zhang Z, Kroon DE, Casstevens TM, Ramdoss Y, Buckler ES. (2007) TASSEL: Software for association mapping of complex traits in diverse samples. Bioinformatics 23:2633-2635.



TASSEL Version 5.0   (Getting Started!)
(Build: May 7, 2020Requires: Java 1.8)


TASSEL Version 5.0 Standalone

(GBS Pipeline V2 - Preferred Version)

                New Getting Started with rtassel

Archived Versions of TASSEL

TASSEL Documentation


TASSEL Pipeline Documentation

TASSEL development has been generously supported by the USDA-ARS and the NSF, as well as free or reduced cost tools including:









We recommend first searching the archives and posting questions on the discussion group

Tassel User Group (


Software Architect
Terry Casstevens (

Analysis Tools / MLM / GLM
Peter Bradbury (

Overall Project Lead
Ed Buckler (

Tassel 1.jpg
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Phylogenetic Tree using Archaeopteryx

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