Location: Crop Germplasm Research
Project Number: 3091-21000-041-07-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Sep 15, 2017
End Date: Sep 14, 2020
The objective of this project is to characterize new accessions of cotton germplasm. Specifically, this project will investigate the genetic diversity and agronomic potential of improved global cultivars in order to: 1) determine the genetic diversity and relationships between two groups of cultivars from Africa; and 2) more fully characterize a portion of the U.S. National Cotton Germplasm Collection. Efforts to characterize germplasm will be complemented and augmented by molecular mapping efforts on the cotton genome.
Cotton germplasm will be characterized with molecular marker profiles to establish genetic relationships between germplasm lines and to characterize genetic diversity within germplasm sets. Molecular mapping techniques will be employed in characterizing genome structure. Data collected from phenotypic characterizations and from molecular characterization and mapping will be maintained in the CottonGen and GRIN-Global databases. An initial project, occuring during the first two years of the project, will involve the phenotypic and molecular characterization of two groups of African cultivars (50 cultivars recently donated to the Collection and 50 cultivars currently in the Collection). Morphological descriptor data will be taken. Molecular characterization of the cultivars/elite lines will take place in ARS facilities by ARS personnel. Molecular diversity will be assessed using a set of 105 simple sequence repeat (SSR) markers. Data from the molecular diversity assessment will be used to calculate genetic similarity coefficients. This coefficient will be further used in a cluster analysis to construct a dendrogram showing relationships between cultivars and a principal component analysis to observe how individual cultivars form groups based on SSR similarities. An analysis of molecular variance (AMOVA) based on the SSR data will measure genetic structure between the two groups of African cotton cultivars. The project may be extended to other germplasm and beyond the initial two years. Complementary efforts to supplement characterization of germplasm through development of molecular markers and sequencing of the cotton genome may occur.