Page Banner

United States Department of Agriculture

Agricultural Research Service

Research Project: Genetic Foundations for Bioenergy Feedstocks Title: A multivalent three-point linkage analysis model of autotetraploids

Authors
item Lu, Yafei -
item Yang, Xiaoxia -
item Tong, Chunfa -
item Li, Xin -
item Feng, Sisi -
item Wang, Zhong -
item Pang, Xiaoming -
item Wang, Yaqun -
item Wang, Ningtao -
item Tobias, Christian
item Wu, Rongling -

Submitted to: Briefings in Bioinformatics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 13, 2012
Publication Date: September 17, 2012
Citation: Lu, Y., Yang, X., Tong, C., Li, X., Feng, S., Wang, Z., Pang, X., Wang, Y., Wang, N., Tobias, C.M., Wu, R. 2012. A multivalent three-point linkage analysis model of autotetraploids. Briefings in Bioinformatics. doi:10.1093/bib/bbs051.

Interpretive Summary: Collectively, these results provide a complete description of switchgrass chromosomes. Furthermore, results indicate genetic divergence between the distinct copies of it’s duplicated genome and allow for the classification of switchgrass plants belonging to divergent genetic pools. Furthermore, the chromosome structure and analysis of switchgrass provides a physical framework for genetic and genomic studies

Technical Abstract: A cytogenetic study was conducted on a dihaploid individual (2n'='2X'='18) of switchgrass to establish a chromosome karyotype. Size differences, condensation patterns, and arm-length ratios were used as identifying features and fluorescence in-situ hybridization (FISH) assigned 5S and 45S rDNA loci to chromosomes 7 and 2 respectively. Both a maize CentC and a native switchgrass centromeric repeat (PviCentC) that shared 73% sequence identity demonstrated a strong signal on chromosome 3. However, only the PviCentC probe labeled the centromeres of all chromosomes. Unexpected PviCentC and 5S rDNA hybidization patterns were consistent with severe reduction or total deletion of these repeats in one subgenome. These patterns were maintained in tetraploid and octoploid individuals. The 45S rDNA repeat produced the expected number of loci in dihaploid, tetraploid and octoploid individuals. Differences observed at the 5S rDNA loci between the upland and lowland ecotypes of switchgrass provided a basis for distinguishing these subpopulations.

Last Modified: 10/22/2014
Footer Content Back to Top of Page