Use of molecular markers and antioxidant properties to study biodiversity and to discriminate blueberries

Bhatt, Dhrumit Shaileshbhai (2021) Use of molecular markers and antioxidant properties to study biodiversity and to discriminate blueberries. Masters thesis, Memorial University of Newfoundland.

[English] PDF - Accepted Version Available under License - The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission. Download (3MB)

Abstract

Blueberries (Vaccinium spp.) have gained much attention worldwide with their potential health benefits and economic importance. Estimation of genetic diversity using molecular markers, antioxidant properties, and their association can reveal genotypes with important characteristics and help in berry improvement programs. Genetic diversity was estimated in blueberry hybrids, wild clones, and cultivars using expressed sequence tag- simple sequence repeat (EST-SSR), genomic (G)-SSR, and EST- polymerase chain reaction (PCR) markers. The antioxidant efficacy was estimated by total phenolic and flavonoid contents in blueberry hybrids, wild clones, and cultivars. Wide diversity existed among the genotypes, for antioxidant properties with the highest variation for 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity (20-fold) followed by the contents of total flavonoids (16-fold) and phenolics (3.8-fold). Although a group of 11 hybrids generated the maximum diversity for antioxidant activity (15-fold), wild clones collected from Quebec, Canada, had the maximum variation for total phenolic (2.8-fold) and flavonoid contents (6.9-fold). Extensive genetic diversity was evident from Shannon's index (0.34 for EST-SSRs, 0.29 for G-SSR, 0.26 for EST-PCR) and expected heterozygosity (0.23 for EST-SSR, 0.19 for G-SSR, 0.16 for EST-PCR). STRUCTURE analysis separated the genotypes into three groups, which were in agreement with principal coordinate and neighbor-joining analyses. Molecular variance suggested 19% variations among groups and 81% among genotypes within groups. Clustering based on biochemical data and molecular analysis did not coincide, indicating a random distribution of loci in the blueberry genome conferring antioxidant properties. However, the stepwise multiple regression analysis (SMRA) revealed that a total of 17 EST-SSR, G-SSR, and EST-PCR markers were associated with antioxidant properties. The outcome of this study will provide valuable information for the selection of blueberry genotypes with desired traits, breeding, and germplasm conservation programs.

Actions (login required)

View Item