Online Event
September 01-03, 2022 | Online Event
GPMB 2022

Sequencing and validation of single nucleotide polymorphism markers linked to carotenoids in cassava (Manihot esculenta Crantz)

Lovina Udoh, Speaker at Plant Conferences 2022
Akwa Ibom State University, Nigeria
Title : Sequencing and validation of single nucleotide polymorphism markers linked to carotenoids in cassava (Manihot esculenta Crantz)

Abstract:

Cassava is a widely grown staple in Sub-Saharan Africa and consumed as a cheap source of calories, but the crop is deficient in micronutrients including pro-vitamin A carotenoids. This challenge is currently being addressed through biofortification breeding that relies on phenotypic selection. Gene-based markers linked to pro-vitamin A content variation are expected to increase the rate of genetic gain for this critical trait. We sequenced four candidate carotenoid genes from 167 cassava accessions representing the diversity of elite breeder lines from IITA. Total carotenoid content was determined using spectrophotometer and total β-carotene was quantified by high performance liquid chromatography. Storage root yellowness due to carotenoid pigmentation was assessed. We carried out candidate gene association analysis that accounts for population structure and kinship using genome-wide single nucleotide polymorphisms (SNPs) generated through genotyping-by-sequencing. Significant SNPs were used to design competitive allele-specific PCR assays and validated on the larger population for potential use in marker assisted selection breeding. Candidate gene sequencing of the genes β-carotene hydroxylase (crtRB), phytoene synthase (PSY2), lycopene epsilon cyclase (lcyE), and lycopene beta cyclase (lcyB) yielded a total of 37 SNPs. Total carotenoid content, total β-carotene, and color parameters were significantly associated with markers in the PSY2 gene. The SNPs from lcyE were significantly associated with color while those of lcyB and crtRB were not significantly associated with carotenoids or color parameters. These validated and breeder-friendly markers have potential to enhance the efficiency of selection for high β-carotene cassava, thus accelerating genetic gain.

Biography:

Dr. Lovina I. Udoh is currently a Lecturer of Plant Genetics and Molecular Biology, Department of Botany, Akwa Ibom State University. She is an alumnus of the international association of research scholars and fellows at the International Institute of tropical agriculture where she was visiting research fellow and research fellow for M.Sc. and Ph.D. programs, in 2011, 2016, respectively. She was part of the HarvestPlus breeding program where her research contributed greatly to provide molecular tools for marker assisted selection breeding for Vitamin A Cassava. Her present research focuses on biofortification of staple crops and DNA barcoding of important medicinal plants.

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