Confirmation of transformability of markers for high carotenoid content in tetraploid potato from diploids

Potato is the fourth most important staple food crop of the world and it contains a wide range of phytochemicals, including carotenoids. Higher animals are incapable of biosynthesizing carotenoids, so these pigments are essentially taken through the diet for their various health promoting activities. Potato varieties vary greatly in their content of carotenoid and characterizing popularly grown potato cultivars for their carotenoid content is very important not only for their better utilization as specialized potatoes with health benefits, but also for further developing new varieties. Therefore, the present study was carried out to estimate the total carotenoid content of 43 popularly grown Indian potato cultivars and to test transferability of the linked markers for carotenoids which are developed and used in only diploid populations of Solanum, in tetraploid population. Total carotenoid content in the Indian potato cultivars varied from 27.92 μg/100 g f.w in Kufri Bahar (Low) to as high as 281.20 μg/100 g f.w in Kufri Chipsona II (Medium). Further, none of the Indian potato cultivars contain high (≥ 350 μg/100 g f.w) level of carotenoids. The oxygen radical absorption capacity (ORAC) which depicts the antioxidant capacity per kilo gram potato was analyzed. A total of 150 tetraploid potato lines including Indian potato cultivars, indigenous, UPOV and exotic clones were screened for the two tightly linked (bch/CAPS and zea) markers. The CAPS bch marker was found to be loosely associated with carotenoid content whereas, zea marker was found to be a rare in the tetraploid population as only 4 out of 150 contained the marker/allele. Estimation of total carotenoid content of these Indian potato cultivars and successful marker transformation in tetraploid potato population would be of great help for the breeders in developing specialized potato cultivars with high nutritional values.