**4. Conclusions and perspectives**

Altering the ω-6 and ω-3 fatty acid profile of the soybean seed/oil has been an important goal for soybean breeders. While low-ALA oils are better-suited for vegetable oil, genotypes with high ALA can be suited in food products that use whole soybeans in various fermented/non-fermented recipes. Therefore, breeding strategies according to the specific requirements are required. For these reasons, three major breeding strategies need be considered to achieve improvement in ω-3 fatty acid content in soybean. 1. To reduce ω-3 fatty acid for soybean oil, which is being achieved with the use of available several mutant lines with reduced ALA concentration in breeding programs. 2. To increase ω-3 fatty acid for soybean foods, which can be achieved by finding new alleles in wild soybeans, and introgressing such alleles in desired cultivars. However, there are many difficulties in this breeding process. Generating mutants with increased ω-3 fatty acid could be very

#### **Figure 4.**

*Schematic representation of the integrated approach involving genomic, biotechnological, and breeding approaches for the improving* α*-linolenic acid in soybean cultivars.*

crucial in achieving this goal. Wild soybeans [76] and some mutants [82] have relatively higher ω-3 fatty acid; however, there is still a lack of clarity and research information on the genes that regulate *FAD3* genes. Therefore, studies investigating the regulators controlling ω-3 fatty acid in soybean need to be carried out. 3. To increase ω-3 fatty acid along with decreasing ω-6/ω-3 ratio, which can be achieved by combining mutant alleles of either of *FAD2-1A* or *FAD2-1B* genes with alleles (genes) governing elevated ALA in wild and cultivated soybeans. The success of these three strategies rely on the availability of genetic and genomic information governing ALA content, which at the moment is limited. Hence, an integrated approach (**Figure 4**) comprising genetic dissection, breeding, and biotechnological approaches is necessary to develop soybeans with desired fatty acid profile.

In last two decades, advances in the genomic and DNA sequencing technologies facilitated the genetic discovery of fatty acid biosynthesis in soybean and other oilseed crops [115]. It is now feasible to screen a large germplasm and mutant collections in quick time using high-density genotyping platforms (such as Axiom SoyaSNP array; [116]), and use the data for genetic and association mapping. Several wild and cultivated soybean genotypes with varied seed fatty acid contents are already known and have been used to develop improved cultivars. Also, many artificial mutant lines have been used in developing segregating mapping populations to identify novel alleles, for which genotyping assays have been developed and used for introgression of desired fatty acid trait in a soybean cultivar. Besides, the recent success of gene-editing technologies in targeting selected sites in the genes regulating fatty acid composition traits has shown the potential to selectively insert mutations in target genes. TALENs, and CRISPR/Cas9 has shown a great potential in soybean for many agronomic traits, and need to be exploited for improving the seed fatty acid composition.

### **Acknowledgements**

This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. 2020R1C1C1008759).

*Breeding Strategy for Improvement of Omega-3 Fatty Acid through Conventional Breeding… DOI: http://dx.doi.org/10.5772/intechopen.95069*
