Exotic genetic libraries: strategies for development and their utilization in plant breeding

  

 Exotic genetic libraries consist of marker-defined genomic regions taken from wild species and introgressed onto the background of elite crop lines. Exotic germplasm can make a wide array of previously unexplored genetic variation rapidly available to plant breeders1. Exotic genetic libraries are comprised of a series of introgression lines (ILs) and chromosome segment substitution lines (CSSLs) collectively covering entire genome of the donor parent. Well characterized ILs/CSSLs have been reported in several crops like tomato, rice, barley. These resources are utilized for genetic map construction, mapping QTLs, gene interactions and their functional analysis for crop improvement3.

Construct an IL collection from the wild accession TRI into the PS background to shed light on melon domestication and to exploit the genetic variability present in the wild accession. variability was observed for FFP, FF, SSC and rind color2. Oryza longistaminata (AA genome) is a wild rice species which is phenotypically inferior to cultivated rice but possesses useful alleles that can be used to improve agronomically important traits. To illustrate the potential of wild rice relatives as a source of novel alleles for rice improvement, a total of 40 chromosome segment substitution lines (CSSLs) of O. longistaminata in the background of the elite japonica cultivar, Taichung 65 were developed and evaluated for yield and yield-related traits5

Exotic genetic libraries consist of ILs and CSSLs which helps in introgression of desired genes from wild species into genetic background of cultivated or elite varieties, which help in reducing the effects of genetic bottleneck and improving the genetic diversity. These libraries can also act as reagents for the discovery and characterization of genes that underlie traits of agricultural value. The advent of high throughput genotyping and phenotyping technologies together with emerging biotechnologies provide new opportunities to explore genetic variation.

References:

1. ZAMIR, D., 2001, Improving plant breeding with exotic genetic libraries. Nat. Rev. Genet., 2(12): 983. 

2.CAMPOS, M., GONZALO, M. J., DÍAZ, A., PICÓ, B., GÓMEZ-GUILLAMÓN, M. L., MONFORTE, A. J. AND ESTERAS, C., 2023, A Novel Introgression Line Library Derived from a Wild Melon Gives Insights into the Genetics of Melon Domestication, Uncovering New Genetic Variability Useful for Breeding. Int. J. Mol. Sci., 24(12):10099. 

3. BALAKRISHNAN, D., SURAPANENI, M., MESAPOGU, S. AND NEELAMRAJU, S., 2019, Development and use of chromosome segment substitution lines as a genetic resource for crop improvement. Theo. Appl. Genet., 132(1): 1-25.

 4. RAMOS, J. M., FURUTA, T., UEHARA, K., CHIHIRO, N., ANGELES-SHIM, R. B., SHIM, J., BRAR, D. S., ASHIKARI, M. AND JENA, K. K., 2016, Development of chromosome segment substitution lines (CSSLs) of Oryza longistaminata A. Chev & Rohr in the background of the elite japonica rice cultivar, Taichung 65 and their evaluation for yield traits. Euphytica., 210(2): 151-163.

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