Genetics and Expression Analysis of Anthocyanin Accumulation in Curd Portion of Sicilian Purple to Facilitate Biofortification of Indian Cauliflower.

The present study was undertaken to know the genetics of purple color of cauliflower curds using a Sicilian purple 'PC-1' and a white curding mid-late group genotype of Indian cauliflower. For this, a cross was attempted between 'DC-466' (white curd) and 'PC-1' (purple curd) and observed intermediate level of purple pigmentation on curds in F ₁ plants. Segregation of F ₂ population (173) revealed that the purple color of the curd was governed by a single gene dominant over white, but the expression of trait was incomplete. It was substantiated by segregation of plants of BC ₁ and F _{2:3(intermediate)} generations into 1(white):1(intermediate) and 1(white):2(intermediate):1(intense), respectively. The F ₂ , B ₁ , and B ₂ generations segregated into purple(intermediate to intense): white curding plants in the ratio of 126: 47, 26:24, and 40:0, respectively fitting well with the Mendelian ratio of single gene for purple curds. However, purple pigmentation on curds ranged from very light to intense, which corroborated with the wide range of anthocyanin content in F ₂ (3.81-48.21 mg/100 g fw). Out of three molecular markers from high resolution map of Pr gene in purple color cauliflower 'Graffiti', only BoMYB3 marker could distinguish purple and white curding parents but did not show co-segregation while investigated in F ₂ population. Expression of BoMYB1 gene was up regulated in both the purple curd genotypes 'PC-1' and 'Graffiti' in comparison to white curded 'DC-466', while BoMYB2 gene was slightly upregulated in 'PC-1' but down regulated in 'Graffiti'. Occurrence of 'broccoli type' F ₂ individuals and their genetic stability in F _2:3 support the intermediate position of 'Sicilian purple' between broccoli (Calabrese) and cauliflower. There was not any correlation between curd coloration and pigmentation on apical leaf and stem portion, indicating difference of expression in 'PC-1' than 'Graffiti'. The information obtained is useful for breeding anthocyanin rich attractive purple curding 'specialty cauliflower' for better consumer health and growers' earnings.
(Copyright © 2020 Singh, Kalia, Meena, Mangal, Islam, Saha and Tomar.)