Genetic relationship between sesame (Sesamum indicum L.) and related wild species based on chromosome counts and isozyme markers

Abstract

Sesame is an orphan crop with little research attention in Kenya. Genetic relationship between cultivated sesame and related wild species in Kenya is not well known. The objective of this study was to determine genetic relationship between traditional landraces of sesame and related wild species using somatic chromosome counts and isozyme markers. Somatic chromosome counts of four wild species revealed a consistent chromosome number of 2n = 32, which differed from that of the cultivated sesame (2n = 26), indicating genetic variation in chromosome counts. Only esterase exhibited significant variation and accession-specific esterase bands were identified. Three cathodic and eight anodic bands were observed and the variable bands ranged from 2 to 6 per accession. Cathodic bands with varied relative migration were observed in wild species only, whereas anodic bands were observed for all the accessions. Accessions of cultivated sesame were more genetically diverse compared to wild species. Morogoro, 107UG, Indian-1 and Indian-2 recorded the highest number of esterase bands, while 103w had the lowest number of bands. Few common bands were found between cultivated sesame and related wild species indicating a distant genetic relationship. Few gene markers are available in sesame and related wild species, therefore, esterase isozymes can contribute to studies in the breeding and genetics of sesame.

Utility of some floral characters in the assessment of genetic diversity in sesame (Sesamum indicum L.)

“…In another study, Azeez, et al (2013) established genetic diversity in sesame and its crosses using crude seed protein while Alege (2015) also used this same technique to investigate genetic diversity in some Nigerian sesame. Several studies have reported the use of isozymes (Isshiki and Umezaki, 1997;Nyongesa et al, 2014) and DNA markers (Akbar et al, 2011;Wei et al, 2011;Adeoti et al, 2011) in the analyses of genetic diversity in sesame. However, there is dearth of knowledge on the usefulness of quantitative reproductive characters in the assessment of genetic diversity in sesame.…”