Individual Listing

4121 BATCHELOR HALL, KEEN HALL
University of California
Riverside, CA 92521

Roose, Mikeal L

Chair and Professor of Genetics & Geneticist

College of Natural and Agricultural Sciences

Botany & Plant Sciences


Biography

I was born in Anchorage, Alaska but spent most of my childhood in Seattle. I attended Reed College in Portland (BA in Biology in 1973) and graduate school at UC Davis (Ph.D. in Genetics in 1979). My dissertation research concerned evolutionary genetics of duplicate genes in diploid and polyploid plants. I conducted postdoctoral research on the genetics and evolution of air pollution tolerance in ryegrass with Professor Bradshaw at the University of Liverpool. My growing interest in applied research eventually led to my present position at UCR when I was hired in 1982 to work on the genetics and breeding of citrus rootstocks. As other UCR faculty in plant breeding retired and were not replaced, I took on responsibility for citrus scion (fruit) breeding and asparagus breeding. The more applied aspects of these research programs are supported by the industries that they serve. My research programs use a wide variety of molecular and genetic tools to explore and better understand the genomes of the plants we attempt to improve, how they evolved, and how they can be conserved. We recently released several new seedless mandarin (tangerine) varieties that may find a place in the market. I find considerable personal satisfaction in conducting research whose products are directly applied and can be "experienced" by the people of California and the world.

Degrees

BA Biology 1973

Reed College

PhD Genetics 1979

University of California, Davis

Research Area

The research program emphasizes the genetics of citrus and its application to the development of improved citrus rootstocks and varieties. A main focus is on determination of the pattern of inheritance of important traits in conjunction with mapping and identification of genetic markers that are inherited together with genes for these traits. Once such markers are identified, we can incorporate marker-aided selection into citrus breeding programs. We developed a high-resolution linkage map using a variety of different marker types. We identified DNA markers closely linked to a gene for citrus tristeza virus (CTV) resistance, and in cooperation with Dr. Erik Mirkov (Texas A&M University), we have identified a 300 kb BAC contig that should contain this gene. Sequencing of this contig is complete and candidate genes are being transformed into citrus varieties to identify the resistance gene. Other projects include cloning a gene that influences fruit acidity, and development of markers for the genes involved in apomixis. Genetic markers are used to analyze diversity in citrus. We develop new citrus rootstocks and scions by hybridization-selection and mutation breeding, and conduct more than 50 rootstock and scion variety trials. We released a new mandarin hybrid, 'Gold Nugget'in 1999, and three new manidarin varieties in 2002. In 1988 I assumed responsibility for the asparagus breeding program. With industry support, we develop new hybrids and evaluate older breeding lines in trials. We also develop and use genetic markers for cultivar identification and for determining the sex of asparagus seedlings.

Publications

Fang, D. Q. and M. L. Roose. 1999. Inheritance of inter-simple sequence repeat markers in citrus. J. Hered. 90: 247-249.

Fang, D. Q. and M. L. Roose. 1999. A novel gene conferring citrus tristeza virus resistance in Citrus maxima(Burm.)Merrill. HortSci. 34: 334-335

Roose, M. L. and N. K. Stone. 1999. Genetics and breeding of asparagus at the University of California, Riverside. Acta Horticulturae 479: 101-107.

Stone, N. K. and M. L. Roose. 1999. Field evaluation of new asparagus varieties at the University of California, Riverside. Acta Horticulturae 479: 185-188.

Roose, M. L., T. E. Williams, J. W. Cameron, and R. K. Soost. 2000. ‘Gold Nugget’ mandarin, a seedless, late-maturing hybrid. HortSci. 35: 1176-1178.

Gulsen, O. and M. L. Roose. 2001. Chloroplast and nuclear genome analysis of the parentage of lemons. J. Amer. Soc. Hort. Sci. 126: 210-215.

Gulsen, O. and M. L. Roose. 2001. Lemons: diversity and relationships with selected Citrus genotypes as measured with nuclear genome markers. J. Amer. Soc. Hort. Sci. 126- 309-317.

Yang, Z. N., X. R. Ye, S. D. Choi, J. Molina, F. Moonan, R. A. Wing, M. L. Roose and T. E. Mirkov. 2001. Construction of a 1.2-Mb contig including the Citrus tristeza virus resistance gene locus using a bacterial artificial chromosome library of Poncirus trifoliata (L.) Raf. Genome 44: 382-393.

Sadka, A., E. Dahan, E. Or, M. L. Roose, K. B. Marsh and L. Cohen. 2001. Comparative analysis of mitochondrial citrate synthase gene structure, transcript level and enzymatic activity in acidless and acid containing Citrus varieties. Austral. J. Plant Physiol. 28: 383-390.

Stone, N. K. and M. L. Roose. 2002. Effective field evaluation of asparagus hybrids using reduced data collection. Acta Horticulturae 589:103-109.

Roose, M. L., N. K. Stone, D. M. Matthews, and J. A. Dodds. 2002. RT-PCR detection of Asparagus 2 ilarvirus. Acta Horticulturae 589:357-363.

Yang, Z. N., X. R. Ye, J. Molina, M. L. Roose, and T. E. Mirkov. 2003. Sequence analysis of a 282-kb region surrounding the Citrus tristeza virus resistance gene (Ctv) locus in Poncirus trifoliata. Plant Physiology 131:482-490.

Krueger, R. R. and M. L. Roose. 2003. Use of molecular markers in the management of citrus germplasm resources. J. Amer. Soc. Hort. Sci. 128:827-837.