Lovina I. Udoh^1,2 , Adenubi Adesoye¹ , Melaku Gedil²

1 Department of Botany, University of Ibadan, Ibadan, Nigeria
2 Bioscience Center, International Institute for Tropical Agriculture (IITA), PMB 5320 Ibadan, Oyo, Nigeria
Author    Correspondence author
Molecular Plant Breeding, 2017, Vol. 8, No. 4   doi: 10.5376/mpb.2017.08.0004
Received: 01 Mar., 2017    Accepted: 01 Jun., 2017    Published: 30 Jun., 2017

This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Udoh L.I., Adesoye A., and Gedil M., 2017, Identification and molecular analysis of pro-vitamin A carotenoid genes in cassava (Manihot esculenta Crantz), Molecular Plant Breeding, 8(4): 38-44 (doi: 10.5376/mpb.2017.08.0004)

Cassava is one of the most important sources of calories in the tropics and consumed as a staple food. Several cassava varieties are deficient in vitamin A. The present work is envisaged towards the genetic improvement of carotenoid content in cassava, by identifying single nucleotide polymorphism (SNP) attributed to variation in carotenoid concentration among some cassava genotypes. Phytoene synthase (PSY), β-carotene hydroxylase (HYD), lycopene β and ε cyclase (LYCB and LYCE), have been found to play a role in increasing levels of β-carotene in plants. A total of 40 lines with varying total carotene content were drawn from a cassava recurrent selection breeding program.  Primers for HYD, LYCB, LYCE, and PSY genes designed from cassava ESTs were used to genotype the cassava lines. Amplified PCR products were purified and sequenced. A total of 169 polymorphisms were detected among the sequences under study both in the coding and non-coding regions of the genes. Analysis of SNPs in relation to carotene content of each accession revealed a variation G/T at 1295^th position of the LYCE reference gene that caused an amino acid exchange from tryptophan (Trp) to leucine (leu) in a high carotene line 07/0593. High total carotene lines recorded the highest number of polymorphism with 42%of entire polymorphisms observed. This indicates that if the whole gene is sequenced unique polymorphisms associated with high carotene cassava can be retrieved for marker development to aid selection for high carotenoid containing cassava germplasm.

Cassava; Pro-vitamin A; Carotenoid biosynthesis genes; Single nucleotide polymorphism