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Molecular Quantitative Genetics <BR>G1: Identify genetic relationships between grain maize lines and use various genetic mapping techniques to identify loci of importance for relevant phenotypic traits. <BR>G2: Develop and investigate populations to understand the genetic basis of stem sugar accumulation, tillering ability, perennial growth habit and photoperiod sensitivity in the C4 grasses: maize, sorghum and sugarcane. <BR>G3: Use computer simulations and bioinformatics to increase knowledge for protocols of genetic investigation and plant breeding methodology. <P>Maize Breeding for South Central States <BR>B1: Introgress exotic maize alleles to increase the genetic diversity of US maize germplasm. <BR>B2: Improve tolerance and resistance to biotic (mycotoxins- especially aflatoxin) and abiotic stresses (salinity, drought and heat) through breeding in addition to genetics. <BR>B3: Develop maize inbreds and populations with improved quality and processing properties for foods, feeds, and industrial products while also having improved agronomics for Texas production.<BR> B4: Use molecular techniques such as marker assisted selection and genomic assisted selection (where feasible), to facilitate the selection of economically important traits.<P> Education <BR>E1: Include graduate students on projects for training and experience. <BR>E2: Jointly develop projects initiated by graduate students to deliver scientifically well-rounded, self-motivated and confident leaders of breeding and genetics for the future. <P>Techniques: To accomplish these objectives in an effective manner, techniques must first be developed for the program that will reduce burdens in cost, labor and time. <BR>T1: Develop/select a common genetic marker screening platform. <BR>T2: Develop data handling pipelines to track and link germplasm with phenotypic and genotypic information. <BR>T3: Develop methods of rapid phenotypic analysis, especially for aflatoxin, such as near infrared spectroscopy (NIRS). <BR>T4: Develop methods to evaluate and increase safety in the handling of aflatoxin contaminated material. Major outputs will include improved germplasm for Texas, well trained graduate students, professional presentations, and journal publications.
Non-Technical Summary: Many genes contribute quantitatively to how a plant looks and behaves. This project investigates genetics important for plant appearance and behavior and then uses this information for improving crops for a variety of traits and systems. A primary end goal is to improve maize (Zea mays L.) inbred lines through breeding for production in the wide range of environments found in Texas. Traits of interest for improvement include yield, agronomics, tolerance and resistance to stress, adaptation, improved nutrition, nutrient use efficiency and improved disease resistance. A specific breeding objective is improved resistance to Aspergillus flavus, which colonizes and produces aflatoxin in maize. In addition to being a major health hazard, the loss liability to Texas maize producers in 2008 from mycotoxins (primarily aflatoxin) was over $30 million (RMA-USDA). Additional genetic traits for long term improvement include tillering ability, perennial growth habit, biomass production, photoperiodism, and stem sugar accumulation. The three products of this program are increased understanding of relevant genetic phenomenon and the dissemination of this information (molecular quantitative genetics), improved germplasms to be delivered to industry (maize breeding for south central states), and most importantly well trained graduate students that can make valuable contributions to industry, academia, and/ or government (educating and training future generations of plant breeders). <P> Approach: Exotic (tropical, subtropical, and wild) germplasm and some temperate germplasm will be used to generate segregating populations with adapted material. Molecular markers, mostly single nucleotide polymorphisms (SNPs) will be employed on these populations for various types of QTL mapping (linkage mapping, association mapping, selection mapping) and genomic selection where appropriate. Inbred lines will also be developed from these populations through pedigree breeding and marker assisted selection. Selected inbreds will be crossed to appropriate testers, including up to five transgenic testers in cooperation with industry breeding programs. A Fall/Winter nursery in Weslaco, TX will be used to rapidly advance material. These test hybrid evaluations will be conducted in up to 13 Texas environments for adaptation, maturity, grain yield, tolerance to stresses, resistance to mycotoxins, composition, and kernel quality for determining inbred superiority. In addition, inbreds and hybrids will be evaluated under stress environments including limiting irrigation, limiting fertilization, late planting, increased salinity and inoculation with A. flavus. Near infrared spectroscopy (NIRS) calibrations will be developed and used to more rapidly identify material resistant to A. flavus colonization and those with improved kernel quality. Specific kernel quality traits of interest will include improved protein (quality protein maize - QPM), red and blue colors, increased endosperm hardness, and superior micronutrient profiles. Molecular fingerprinting data will be used to classify inbreds and to choose parental lines for breeding populations. Computer simulations of population development and selection will be performed to refine genetics and breeding methodology. Graduate students will be involved in all of these processes. Major outputs will include improved germplasm for Texas, well trained graduate students, professional presentations, and journal publications.