Institute for Integrative Genome Biology


Mikeal RooseMikeal Roose

Professor of Genetics;
Department Chair 

Mailing Address:

Botany and Plant Sciences
Batchelor /4121
University of California
Riverside, CA 92521

Phone: (951) 827-4137
Fax: (951) 827-4437
Email: mikeal.roose@ucr.edu

UCR Living the Promise Profile


PhD 1979 University of California, Davis
BA 1973 Reed College

College/Division Affiliation:

College of Natural and Agricultural Sciences

Areas Of Expertise:

DNA Marker Analysis; Genomics; Linkage Mapping; Citrus; Asparagus

Research Summary:

The major focus of my research program is on the development and implementation of improved methods for crop improvement, particularly for citrus and asparagus. This research uses a wide variety of techniques and ranges from genetic engineering to hybridization-selection and field trials of new varieties.  Specific projects related to IIGB are outlined below.

Development of high-density genetic maps of citrus including genes for disease resistance and other traits.
The objective of this project is to develop dense genetic linkage maps of two important varieties, sweet orange (Citrus sinensis L.) and trifoliate orange (Poncirus trifoliata L. Raf.). Trifoliate orange is used as a rootstock for citrus. Progeny of several different crosses between the varieties are being analyzed for SSR and SNP markers. We are exploring use of DNA microarrays for mapping large numbers of SNPs.

Use of molecular markers to understand phylogeny and genetic diversity of citrus.
We have used various types of DNA markers, including RFLPs, RAPDs, ISSRs, and SSRs to characterize citrus germplasm and relationships. We have identified putative hybrid accessions based on high heterozygosity and lack of unique alleles, and studied their probable parentage. ISSR (inter-simple sequence repeat) markers are useful for distinguishing hybrid seedlings from apomictic seedlings because they provide a complex "DNA fingerprint" that targets rapidly evolving sequences. A graduate student, Noelle Barkley, recently completed a study of 24 SSR markers in 370 mostly sexually derived accessions from the Citrus Variety Collection and determined population structure and identified putative hybrid accessions. Current work is focused on sequencing a set of dispersed genes in diverse accessions.

Positional cloning of a gene for citrus tristeza virus resistance.
A collaborative project with Dr. T. E. Mirkov (Texas A&M University) is directed toward cloning a Poncirus trifoliata gene that causes resistance to citrus tristeza virus. We developed high-density linkage maps of the region surrounding this gene and sequenced a 282 kb BAC contig that should contain the gene. Candidate genes are now being tested by transformation.

Development of EST resources in citrus.
To develop public resources for citrus genomics research, we collaborated with Dr. T. J. Close (UCR) to develop cDNA libraries from various citrus tissues, sequence clones, assemble these sequences into contigs, and annotate assemblies. The project target of 100,000 ESTs was reached in January 2005. HarvEST: Citrus (http://harvest.ucr.edu/) provides a free, PC-compatible EST database and sequence viewer for all public EST sequences from citrus. In 2006, an Affymetrix microarray for analysis of citrus gene expression and mapping was released. This is being used to analyze gene expression in response to stress and between genotypes.

Selected Publications:

List of publications from PubMed

Lab Personnel:

Federici, Claire
Staff Research Associate —  Molecular markers for citrus, rootstock breeding
Kupper, Ricarda
Staff Research Associate —  Citrus rootstock breeding and evaluation 
Stone, Neil
Staff Research Associate —  Asparagus breeding
Kostecki, Maria
Agricultural Technician — Asparagus breeding
Williams, Timothy
Staff Research Associate — Citrus scion breeding
Ramadugu, Chandrika
Research Scientist — Molecular genetic analysis of citrus evolution and diversity
Alvarez, Juan
Agricultural Technician— Plant care and field data collection
Crowley, Jennifer
Ph.D. Student — Molecular analysis of induced mutation in citrus
Patne, Sai
Ph.D. Student — Chemical genomic approaches to Liberibacter diseases


More Information

General Campus Information

University of California, Riverside
900 University Ave.
Riverside, CA 92521
Tel: (951) 827-1012

Career OpportunitiesUCR Libraries
Campus StatusDirections to UCR

Genomics Information

Institute of Integrative Genome Biology
2150 Batchelor Hall

Tel: (951) 827-7177
E-mail: Aurelia Espinoza, Managing Director