Location: Genetics and Sustainable Agriculture Research
2024 Annual Report
Objectives
1. Conduct research to improve the nematode resistance, disease resistance, seed oil quality and genetic base of cotton and develop and release superior germplasm with high levels of those traits, in addition to improved agronomic traits.
2. Conduct research to discover genes for improving fiber quality, flame retardance and other nonwoven fiber characteristics, and work with cotton fiber bio-scientists, chemists, and ginners to develop superior cotton germplasm with those traits that enhance the economic value of cotton in the marketplace.
3. Conduct innovative research to identify and release climate resilient cotton germplasm with improved fiber yield and stability, water use efficiency, and tolerance or resistance to abiotic stresses.
Approach
The overarching goal of this project is to develop and use novel approaches to develop and utilize non-traditional germplasm resources to broaden the genetic base for cultivar development. We will do this through the use of specific random mated populations we have previously developed, followed by development of recombinant lines comprising specific MAGIC populations of Recombinant Inbred Lines (RIL) and working with collaborators to evaluate these MAGIC populations for specific traits that are needed to improve cotton fiber production, for new traits that open opportunities for new types of cotton products or cotton derived products, for resistance to three species of nematodes, and for climate resilient traits that can be bred into cultivars. As genes for useful traits are discovered we will determine inheritance and discover markers useful in selection for the trait in breeding populations.
We will utilize two types of novel approaches:
1) The use of 62 chromosome substitution lines (CSL) developed by Collaborator at Texas A & M University. These CSL lines are from the tetraploid species, Gossypium barbadense, G. mustelinum, and G. tomentosum. Select individual chromosomes from these three related tetraploid species are substituted individually into a common G. hirsutum inbred line TM-1. Thus, each CSL has 25 chromosome pairs in common and one pair from another tetraploid species. Some CSL involve whole chromosome substitutions, and some involve either the long or short arm of a specific chromosome. A few involve parts of two chromosomes in a translocation arrangement. These CSL have been provided to us in a previous collaborative project. We now have developed homozygous euploid fully fertile lines from each of these CSL.
2) The use of 4 previously developed random mated populations. a) RMUP a random mated population of 11 diverse cultivars or breeding lines; b) RMBUP a random mated population of 18 CSL from G. barbadense crossed with 3 Upland cultivars; c) RMPAP a random mated population from 30 exotic G. hirsutum day neutral derived primitive accessions from Mexico and the islands in the Caribbean, and d) RMBHMTUP a random mated population of 32 non-G. hirsutum CSL involving 12 from G. barbadense, 8 from G. mustelinum, and 12 from G. tomentosum.
Progress Report
We proposed a new method and developed the corresponding R scripts, which can be used to properly predict genotypic values for long-term crop trial data. It will greatly enhance the utilization of historical cotton trial data. One manuscript was developed and will be submitted to a journal for publication.
Numerically evaluated a statistical method that can be used to remove field spatial pattern. Simulation results and application of a cotton field trial data showed that this method is promising to improve field trial data analysis when field spatial pattern exist.
Made F1 crosses with chromosome substitution lines showing tolerance to 2,4-D herbicide. Evaluated chromosome substitution (CS) lines showing 2,4-D tolerance in field trial and select the CS lines with open bolls. Planted additional field trial to validate the selected 2,4-D tolerance CS lines. Self-pollinated F1 crosses related to 2,4-D tolerance. Planted parents with 2,4-D tolerance to make additional F1 crosses.
Twelve rows of CIR1348 x TM-1 F2 seed were planted in the nursery this summer. Individual plants that flower in keeping with day-neutrality will be self-pollinated to produce F3 families that can be evaluated for RKN resistance.
With our collaborators at SRRC, we have discovered that non-woven fabric made from lint of several of our recombinant inbred lines is flame retardant. There is currently no way for a breeder to determine which plants in a segregating generation will produce fire retardant fabric. This is a major bottleneck for the breeder. We grew and harvested individual plants of F2 generation of a cross of fire retardant recombinant inbred line by non-retardant recombination inbred line. Lint from 400 individual F2 plant was supplied to two collaborators to determine if difference in fiber from individual plants can be related to fire retardancy. Two different approaches are being attempted, one using engineering principles related to reflectance and two using the melting point of individual lint samples. We have also planted F3 progeny rows from seed of the 400 individual F2 plants to produce enough lint to make non-woven fabric from each progeny row which will be tested for fire retardancy. We are seeking a high correlation between one of the two methods and fire retardancy of the cloth that the breeder can use to classify individual plants for fire retardancy without having to go to the fabric making stage. We are also trying to find a molecular marker to tag the fire retardant plants, but thus far have not been successful.
We have developed germplasm lines with high levels of oleic acid in the fatty acid profile of seed. We are continuing to develop this area of research and have planted progeny rows of lines that have a favorable level of fatty acid as oleic acid.
Our four multiple advanced generation intercross (MAGIC) populations of recombinant inbred lines (RIL) continue to yield useful results and new traits for the cotton industry. We are currently growing a new seed increase of our 11 parent MAGIC recombinant line population as the current seed are several years old.
Accomplishments
