USDA/ARS/MWA - Soybean/Maize Germplasm, Pathology & Genetics Research Unit
&University of Illinois at Urbana/Champaign - Department of Crop Sciences
S-123 Turner Hall
1102 South Goodwin Avenue
Urbana, IL 61801-4730
|(217) 333-6631 [phone]
(217) 333-6064 [fax]
7,396 seed samples have been supplied in response to 450 requests for 2012. These include 153 requests received from 27 foreign countries. This has by far been a record-breaking year for requests, exceeding the total number (420) received last year, which was also a record breaker. Before that, the previous annual record was 332 requests filled in 2002. Interest in reverse genetics tools, such as the UniformMu sequence indexed stocks, continues to grow. Presently, requests for UniformMu stocks represent more than 40% of our total requests. Other popular stock requests include the NAM RILs and other mapping populations, Hi‑II lines, ig1 lines, Stock 6 haploid-inducing lines, male sterile cytoplasms, and Maize Inflorescence Project EMS lines.
Approximately 6.0 acres of nursery were grown this summer at the Crop Sciences Research & Education Center located at the University of Illinois. Seasonable spring weather allowed us to plant our crossing nurseries in a timely manner, and warmer than normal weather during the growing season accelerated our pollination season. There were sufficient stands for an adequate increase in most instances. However, during the height of our pollination season in early July, 100+ degree temperatures resulted in drastically reduced seed sets on certain critical days; weekly supplemental irrigation helped to mitigate damage due to drought. Because of the spread of maturities in our materials, few stocks will need to be replanted next year as a result of the excessive heat. The increase in heat units this summer allowed for a relatively early harvest. Moderate temperatures and low plant stress later in the season resulted in acceptable yields from the pollinations that were not affected by excessive heat.
Special plantings were made of several categories of stocks:
1. Plantings were made of donated stocks from the collections of Phil Becraft (thk1), James Brewbaker (outcrosses of unique Hi27 near-isogenic mutant lines to B73), Vicki Chandler (mop1, mop2, mop3, rmr1, rmr2, B1, and dwarf variants), Susan Gabay-Laughnan (d1 and emp4 alleles), Andrea Gallavotti (various inflorescence mutants), Sarah Hake (kn1 alleles), Thomas Hartwig (na1, na2, and url1 alleles), David Jackson (fea2 and abph1 alleles), Gerry Neuffer (dominant EMS-induced mutants), Snook Pataky (Rp and Rpp variants), Pat Schnable (A1-b), Nathan Springer (brd1-m1), Clint Whipple (tasselsheath mutants) and others. We expect to receive additional accessions of stocks from maize geneticists within the upcoming year.
2. We are continuing our attempts to recover instances of the lapsed y5 locus from PI accessions of orange endosperm tropical flints and are continuing collaborations to identify the specific gene products associated with previously uncharacterized (or incompletely characterized) white endosperm/albino seedling loci. Through tests of allelism, we have identified new alleles at the y1, brd1, al1, w3, and d1 loci. The photosynthetic mutant ppr10 was found to be allelic to l15, and br3 was found to be allelic to bv1.
3. Due to lack of personnel, we have discontinued active curation of the A-A translocation stocks that were previously maintained by Janet Day Jackson. However, one last attempt was made to increase translocation stocks that had not been grown since 1990. Outcrosses of these translocations were made to standard in our 2011 winter nursery and the outcrosses were grown in our 2012 summer observation to confirm by pollen examimation that they actually carry a translocation.
4. Stocks produced from the NSF project "Regulation of maize inflorescence architecture" (see: http://www.maizegdb.org/MIP/) were grown again this summer. Approximately 250 families of M2 materials that were produced between 2003 and 2007 were grown to increase seed supplies and recover previously observed mutations; this also included previously phenotyped families that had limited seed supplies. In addition, 1,510 families of 2010 and 2011 EMS seed increase materials were grown for adult plant observation and 419 families were screened in sand benches for seedling traits; the materials observed include mutated A619, B73 and Mo17 inbred lines, A619xB73 and B73xMo17 hybrid, and various other inbred lines.
We grew a winter nursery at the Illinois Crop Improvement Association's facilities in Juana Díaz, Puerto Rico during the 2011/2012 season. Critical plantings of a limited number of stocks were made in our greenhouse facilities.
We received some Rpp* (resistance to Puccinia polysora; Southern rust) stocks from Jerald (Snook) Pataky. These are factors that are not alleles of Rpp9. All but two of these were given to us as homozygous for the trait, so they can be easily maintained. Unfortunately, Snook was unable to characterize F3 material for these last two before he retired; these two are considered by him to be the most important (Rpp*-Cavalry and Rpp*-Suregold). We made arrangements with Clayton Hollier, at Louisiana State University, to conduct Southern rust inoculation tests on plants grown from the seeds of Snook's F3 ears. However, the plants did not survive the heat and drought he experienced this summer. He will try again next summer.
We currently have 8,273 UniformMu sequence indexed stocks, produced by the "Construction of comprehensive sequence indexed transposon resources for maize" project (http://www.maizegdb.org/documentation/uniformmu). We have also recently received 200 stocks from the "Genome-wide mutagenesis of maize using Ac/Ds transposons" project (http://www.plantgdb.org/prj/AcDsTagging/).
Our IT Specialist has continued to make updates and improvements to our curation tools, which are used to maintain data for our collection. These tools input our public stock data directly into MaizeGDB to give maize scientists access to up-to-date information about our collection. The tools are also used for our internal database (e.g. inventory, pedigrees and requests). A tool for entering and managing harvest notes has been mostly completed. The harvest notes tool allows COOP staff to quickly migrate information from harvest to inventory as appropriate, easily generate harvest tags and makes it easier to find information about the parent pedigrees of harvested plants, or individual pedigrees. A "family tree" tool was written that allows COOP staff to quickly see the ancestors or descendants of any pedigree family, which has been useful for finding and fixing problems in our database as well as providing a new view of existing data. The family tree tool gives COOP staff quick access to pedigrees listed in the ancestors or descendants graphs. Importing data from MaizeGDB into our local database has been streamlined. We work with MaizeGDB to make sure our tools continue to interoperate well with MaizeGDB's databases, plus offer suggestions on where to go in the future. Maintenance continues on our web site (http://www.uiuc.edu/ph/www/maize).
Agric Sci Res Tech (Plants)
Information Tech Specialist