Molecular Markers for Genetic Diversity Studies in African Leafy Vegetables

Abstract

African leafy vegetables are becoming important crops in tackling nutrition and food security in many parts of sub-Saharan Africa, since they provide important micronutrients and vitamins, and help resource-poor farm families bridge lean periods of food shortage. Genetic diversity studies are essential for crop improvement programmes as well as germplasm conservation efforts, and research on genetic diversity of these vegetables using molecular markers has been increasing over time. Diversity studies have evolved from the use of morphological and biochemical markers to molecular markers. Molecular markers provide valuable data, since they detect mostly selectively neutral variations at the DNA level. They are well established and their strengths and limitations have been described. New marker types are being developed from a combination of the strengths of the basic techniques to improve sensitivity, reproducibility, polymorphic information content, speed and cost. This review discusses the principles of some of the established molecular markers and their application to genetic diversity studies of African leafy vegetables with a main focus on the most common Solanum, Amaranthus, Cleome and Vigna species.

Mating biology, nuclear DNA content and genetic diversity in spider plant (Cleome gynandra) germplasm from various African countries

“…Of all studies dealing with the use of molecular markers in genetic diversity studies in African leafy vegetables (reviewed by Omondi et al. ), only one study with limited scope could be listed for C. gynandra . Several molecular marker techniques, such as random amplified polymorphic DNAs (RAPD) (Williams et al ), amplified fragment length polymorphic (AFLP) (Vos et al.…”

“…), inter‐simple sequence repeats (ISSR) (Zietkiewicz et al ) and simple sequence repeats (SSR) (Tautz and Renz, ), have been applied in molecular diversity studies of African leafy vegetables (Omondi et al. ). K'Opondo et al () assessed the genetic variation of selected C. gynandra morphotypes from western Kenya using RAPD markers and were able to cluster the morphotypes into three clusters according to the colour of the stem and petioles, where purple stems, purple petioles (PP), green stems, green petioles (GG) and GP clustered apart from PG morphotypes.…”

“…Despite the considerable benefits of the crop, it is still regarded as a minor crop and has a lack of support from research and development programmes to develop high-yielding cultivars and improved cultural practices (Onyango et al 2013). Of all studies dealing with the use of molecular markers in genetic diversity studies in African leafy vegetables (reviewed by Omondi et al 2016), only one study with limited scope could be listed for C. gynandra. Several molecular marker techniques, such as random amplified polymorphic DNAs (RAPD) (Williams et al 1990), amplified fragment length polymorphic (AFLP) (Vos et al 1995), inter-simple sequence repeats (ISSR) (Zietkiewicz et al 1994) and simple sequence repeats (SSR) (Tautz and Renz, 1984), have been applied in molecular diversity studies of African leafy vegetables (Omondi et al 2016).…”

“…Of all studies dealing with the use of molecular markers in genetic diversity studies in African leafy vegetables (reviewed by Omondi et al 2016), only one study with limited scope could be listed for C. gynandra. Several molecular marker techniques, such as random amplified polymorphic DNAs (RAPD) (Williams et al 1990), amplified fragment length polymorphic (AFLP) (Vos et al 1995), inter-simple sequence repeats (ISSR) (Zietkiewicz et al 1994) and simple sequence repeats (SSR) (Tautz and Renz, 1984), have been applied in molecular diversity studies of African leafy vegetables (Omondi et al 2016). K'Opondo et al (2009) assessed the genetic variation of selected C. gynandra morphotypes from western Kenya using RAPD markers and were able to cluster the morphotypes into three clusters according to the colour of the stem and petioles, where purple stems, purple petioles (PP), green stems, green petioles (GG) and GP clustered apart from PG morphotypes.…”

Genetic diversity analysis and molecular characterization of grain amaranth genotypes using inter simple sequence repeat (ISSR) markers

“…Morphological characters have been used for diversity analysis in Amaranthus spp. (Omondi et al 2016). The limitations of these characters result from the flexibility of certain characters and alterations caused by environmental conditions.…”