Genes in Pepper Conferring Microspore Regeneration Capacity
Creators: name: University Of California Office Of The President
Publisher: name: University of California Office of the President
publisherIdentifier: https://ror.org/00dmfq477
publisherIdentifierScheme: ROR
Year: 2024

description: Peppers (Capsicum annuum L.) are a major vegetable crop in the U.S., ranking fourth in total market value after lettuce, tomatoes, and onions. California production accounted for 46% of total U.S. bell pepper value and 38% of chili pepper value in 2008, making it by far the leading state. Bell peppers produced in California were valued at over $312 million in 2008. Most major pepper breeding companies sell seeds for the California market and many have breeding and research facilities in the state to develop varieties adapted to California growing environments. Peppers therefore provide significant employment and income in California both in the crop production and processing sector and in the research and development sector. In pepper, most commercial varieties in the US are F1 hybrids produced by the controlled crossing of selected distinct inbred parents to produce seed for sale. The introduction of novel traits from diverse sources and production of reproducible F1 hybrids requires development of these inbred parents by repeated selfing and selection over multiple generations in order to incorporate new traits into the F1 hybrid. This process of creating inbred parental lines can be significantly advanced by using doubled haploid (DH) lines. In this process, pollen grains having a haploid genetic complement (half of the normal number of chromosomes) can be cultured in the laboratory to form embryos. The chromosomes in the microspores can be induced to duplicate, creating identical chromosome pairs and resulting in a completely inbred plant following regeneration. These DH lines are extremely useful for rapidly creating inbred parental lines and for efficiently incorporating new traits into improved varieties. A limitation to the broader application of DH lines in pepper breeding is the difficulty in achieving regeneration of viable plants from pollen. Genotypes vary in the relative success with which DH lines can be regenerated. This genetic variability in regeneration capacity (RC) limits the parental genotypes to which the DH method can be applied, as it requires an efficient process for DH induction and regeneration. Knowledge of the genes conferring this trait and DNA-based markers associated with them would enable breeders to incorporate regeneration capacity into diverse lines and broaden the application of DH-based breeding strategies. In this project, we will identify the genetic basis for RC in pepper. Our approach utilizes recent developments in genomics and genetic mapping along with specially created populations to pinpoint the genes controlling the RC trait. By identifying the gene(s) responsible for this trait, breeders will be able to develop lines that are amenable to the application of DH-based breeding methods. This will lead to more rapid improvement of pepper varieties with traits desired both by producers (e.g., disease resistance, stress tolerance, yield) and consumers (e.g., color, flavor, nutritional content).