Identification of Polymorphic Microsatellite Markers among Potato (Solanum tuberosum L.) Genotypes differing in Processing Traits

Author: Soumya Shetty, B.T. Krishnaprasad, S. Shyamalamma, R.L. Ravikumar, H. Amarananjundeswara, Geeta Govind and S. K. Pooja

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Abstract

Potato (Solanum tuberosum L.) is a annual vegetable crop, which belongs to Solanaceae family. In India, there is a huge demand for potato varieties suitable for processing as they have been widely used in agro-based industries. However, certain morphological, bio-chemical and physico-chemical attributes are necessary in potato varieties to meet the requirement for industrial use. In the present study, 35 genotypes of potato differing in processing traits were evaluated for biochemical and physico-chemical properties such as starch, apparent amylose content, amylose: amylopectin ratio and total carotenoids. Highest starch content of 81 per cent was documented in FC-3 with 0.23 percent apparent amylose content and 1:4.5 Amylose: Amylopectin ratio. Further, potato is an auto-tetraploid species with clonal propagation and has got narrow genetic diversity conserved during asexual propagation. Use of molecular markers is most preferred method for the assessment of genetic diversity in this crop. Among the microsatellite markers, SSR (simple sequence repeats) markers are most preferred due to their distribution throughout the genome, co-dominant in nature, low cost and reproducibility. SSR markers linked to processing traits are useful in identifying suitable potato genotype for processing. Hence, in the same genotypes, polymorphic SSR markers were also analysed using known markers viz., STM3009, STWAXY, Inh2α, STGBSS, STI007, STI028, STI060, STI014, STI021, STM0019, STM1106 and STM1051 related to processing traits. Among the different SSR primers evaluated, STWAXY, Inh2α and STI060 showed polymorphism. The size of the amplified product varied from 130 base pairs (Inh2α) to 215 base pairs (STM Waxy). In which, ST Waxy characterized as granule bound starch synthase and Inh2α as vacuolar in vertase inhibitor gene, involved in potato starch metabolism. From the study, it was concluded that SSR markers can be used in the identification of potato varieties suitable for processing type with superior tuber quality traits for further food and non food industrial applications.

Keywords

Potato, SSR, polymorphism, physico-chemical, biochemical properties

Conclusion

In this study, genotypes were initially screened for their biochemical and physico-chemical properties and significant differences were observed among the hybrids. Highest starch content of 81 per cent was documented in FC-3 with 0.23 per cent apparent amylose content and 1:4.5 Amylose: Amylopectin ratio.Usually, starch properties are considered to be a key factor affecting the functional properties of processed potatoes, which are found to be influenced by cultivars and by environmental factors. Further, in the study, polymorphic SSR markers were also analysed using known markers in the working population.Among the SSRs evaluated, only STWaxy, Inh2α and STI060 showed polymorphism. STWaxy is characterized as granule bound starch synthase and Inh2α is characterized as an vacuolar in vertase inhibitor involved in potato starch metabolism. However, potato genotypes that show polymorphism for the SSRs, also display variation in their starch metabolism or not, requires future studies. As potato starch is widely used in the food industry and other industries like textile and paperbecause of its unique physico-chemical properties, current study on use of SSR markers for the assessment of polymorphism is helpful in the identification of potatohybrids suitable for processing with the superior quality traits.

References

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How to cite this article

Soumya Shetty, B.T. Krishnaprasad, S. Shyamalamma, R.L. Ravikumar, H. Amarananjundeswara, Geeta Govind and S. K. Pooja (2022). Identification of Polymorphic Microsatellite Markers among Potato (Solanum tuberosum L.) Genotypes differing in Processing Traits. Biological Forum – An International Journal, 14(4): 607-613.