TEXAS A&M PLANT BREEDING Bulletin

Transcription

1 COLLEGE OF AGRICULTURE AND LIFE SCIENCES Department of Soil and Crop Sciences Academic & Student Advising Office TEXAS A&M PLANT BREEDING Bulletin April 2012 Kendra Gregory recently completed her M.S. work and successfully defended her thesis titled Degree of Whiteness and Maturity among World Cotton Cultivars. Kendra evaluated the degree of fiber whiteness using colorimetric technology and standards approved by the International Commission on Illumination (CIE), standards not used by the USDA to class upland cotton in the United States and other countries. The CIE sets standards for white on three color dimensions, those being white to black (reflectance), red to green, and yellow to blue. Whiter cotton lint would reduce the amount of bleaching required in the dying process, which potentially would reduce environmental pollution, thus improving an already natural product. Kendra evaluated 12 accessions from China, 7 from west Africa, 10 south Africa, and 7 from the United States. She also preformed a line x tester analysis to determine combining ability for color. She found that genetic variability does exist among theses cultivars, since some African cultivars had superior reflectance values and decreased yellowness and some Chinese cultivars had decreased greenness, both resulting in whiter lint. She also discovered that it is difficult to decrease greenness, without adversely affecting reflectance values and increasing yellowness. Kendra noted that although genetic variability exists for degree of fiber whiteness, the cost and difficulty of phenotyping complicates the implementation of a breeding program specifically for cotton fiber whiteness. Kendra also worked with a prototype machine, the Cottonscope, which uses polarized light to determine fiber maturity on a relatively small fiber sample. The wide-

2 scale use of the Cottonscope will not happen for awhile, but it holds promise to better aid cotton breeders in their selection processes. If further research validates the Cottonscope, then breeders will have technology that will replace the use of micronaire for evaluating and selecting for fiber maturity. Micronaire, as all cotton breeders are aware, cannot distinguish between fiber maturity and fiber fineness. Kendra will receive her M.S. in Plant Breeding in May I had the pleasure of serving as her committee co-chair along with Eric Hequet, Associate Director of the Fiber and Biopolymer Research Institute at Texas Tech University. Kendra will be pursuing a Ph.D. in Crop Science at Washington State University, where she will work in their winter wheat breeding program. Kendra is originally from Pittsburgh, Pennsylvania, where she developed her interest in agriculture. She received her B.S. from Abilene Christian University in Environmental Sciences with an emphasis in field technologies. She will marry Dan Jernigan this summer before attending Washington State. When not thinking about plant breeding, Kendra enjoys languages, reading, and outdoor activities. We wish Kendra the best and look forward to interacting with her at professional meetings and other venues for years to come. Gerald Neil De La Fuente grew up in Pearson, TX. He received his B.S. from Texas A&M in Plant and Environmental Soil Science in December 2010 and will receive his M.S. degree in May. He actually began his M.S. research as an undergraduate with Seth Murray, corn breeder with AgriLife Research and the Department of Soil and Crop Sciences. Gerald will be moving Iowa State University in June to pursue a Ph.D. with Thomas Lubberstedt. His Ph.D. studies with deal with doubled haploids in corn.

3 Gerald noted that he loved agriculture since I was a little kid. We lived just down the road from a farm run by one of my dad s childhood friends: Mark Lamon. I can remember being glued to the window as a kid as we drove by looking to see what was going on at the farm, dreaming that one day I could be a part of it. From when I was 12 to about 21 I spent most, if not all, of my spring, summer and winter breaks on the farm. I actually started at Texas A&M in Biomedical Engineering but by the end of fifth semester I still had not found a concentration within that major that interested me. Still having that love for agriculture, I decided to switch into Soil and Crop Science. It was the best decision I have ever made. I accepted a student worker position with George Hodnett working with Bill Rooney s sorghum wide cross program. This was my first exposure to the world of plant breeding, and I was immediately captivated. I found that I really enjoyed pollination season and field work in Dr. Rooney s program. I knew that I had found my calling in plant breeding. Gerald accepted a Graduate Research Assistant position with Seth Murray in corn breeding. His M.S. research involved breeding corn for improved drought tolerance and aflatoxin resistance. Overall, the two major challenges to growing corn in Texas are drought and aflatoxin, a result of infestation by the fungus Aspergillus flavus. Resistance to aflatoxin and tolerance to drought are two highly complex and quantitative traits, thus complicating selection. Our approach involved some interdisciplinary cooperation between a breeding program (Seth Murray), a molecular biology program (Mike Kolomiets), and pathology program (Tom Isakeit). Knockout mutants developed by Dr. Kolomiets lab at two genes of interest, ZmLOX4 and ZmLOX5, showed drought tolerance and aflatoxin resistance, respectively. The team hypothesized that natural variation could be found at these loci and screened (by sequencing) 400 inbred lines of corn from two association mapping panels that capture most of the diversity in modern domesticated corn. Unfortunately they found little diversity in these two genes, but did find natural knockouts and some lines with two copies of ZmLOX5, which are being backcrossed this year. The 400 inbred lines were also testcrossed to isoline mutants of ZmLOX4 and ZmLOX5 to evaluate functional copies of the alleles in different genetic backgrounds. The severe drought of 2011 was perfect for this study and Gerald obtained good separation of phenotypes. The study is being repeated this year, under the direction of a fellow graduate

4 student in Seth s program, Ivan Barrero, who will take the four year project to its completion and perform the association mapping analyses, hopefully revealing new alleles that confer drought tolerance and aflatoxin resistance. Gerald s research plots during the severe drought of Other News Plant Breeding Positions Sugarcane Research Geneticist: GS-12/15, Permanent Full Time position. This position is for the Sugarcane Research Unit, Houma, LA. This position replaces previous position held by Dr. Thomas Tew. To access the USAJOBS Website, press Ctrl right click to the following link: Cotton Breeder and Station Manager with Bayer CropScience in Australia. - bcs.jobs@bayer.com Station Manager and Plant Breeder with Dow AgroSciences in Corcoran, CA. - Traits-R&D-Job-CA-93212/ / Soil and Crop Science Visitors Claudia Schabel, Talent Acquisition specialist with Pioneer visited with Steve Hague s undergraduate plant breeding class earlier this month.

5 Former Texas A&M Plant Breeding students making a difference (graduate committee chair in parenthesis) Curtis Wiltse (Rooney) Plant Breeder with Beck s Seed Company. Ryan Bading (Rooney) Scientist with Monsanto, Bishop Texas Rafael Mateo (Rooney) Commercial Breeder with Monsanto, London, ONT Miguel Gutierrez (Rooney) Commercial Corn Lead-Central, Chesterfield, MO Polly Longenberger (Smith) Corn Breeder with Pioneer, Darren Jones (Smith) Cotton Breeder with Monsanto, Lubbock, TX Ray Kennett (Smith) Tomato Breeder with H.M. Clause in California Reminder: NAPB Annual Meeting, August 6-8, 2012 in Indianapolis The National Association of Plant Breeders will hold its annual meeting August 6-8, 2012 in Indianapolis, with the theme of Sustaining Life through Plant Improvement. The annual meeting is an opportunity for breeders and allied scientists to stay updated on recent innovations in plant science and to discuss public policy issues relevant to plant breeding. The meeting also provides an important venue for graduate students to present their research, meet with potential employers, and become acquainted with plant breeding graduate students from other universities. This year s meeting will be hosted by Dow AgroSciences. More information and registration for the meeting is available at Early registration ends June 1. Please direct comments concerning this bulletin to Wayne Smith, cwsmith@tamu.edu or