Genetic Diversity of NamibianPennisetum glaucum(L.) R. BR. (Pearl Millet) Landraces Analyzed by SSR and Morphological Markers

Abstract

Current Pennisetum glaucum (L.) R. BR. cultivars in Namibia have overall poor performance posing a threat to the nation's food security because this crop is staple for over 70% of the Namibian population. The crop suffers from undesirable production traits such as susceptibility to diseases, low yield, and prolonged reproductive cycle. This study aimed to understand the genetic diversity of the crop in Namibia by simple sequence repeats (SSRs) and morphology analysis. A total of 1441 genotypes were collected from the National Gene Bank representing all the Namibian landraces. A sample of 96 genotypes was further analyzed by SSR using Shannon-Wiener diversity index and revealed a value of 0.45 indicating low genetic diversity. Ordination using Principal Coordinate Analysis (PCoA) on SSR data confirmed clusters generated by UPGMA for the 96 P. glaucum accessions. UPGMA phenograms of 29 morphological characterized genotypes were generated for SSR and morphology data and the two trees revealed 78% resemblance. Lodging susceptibility, tillering attitude, spike density, fodder yield potential, early vigour, and spike shape were the phenotypic characters upon which some clusters were based in both datasets. It is recommended that efforts should be made to widen the current gene pool in Namibia.

Start codon-targeted marker evaluation of genetic relationship and population structure in southern Nigerian fluted pumpkin (Telfairia occidentalis Hook F.) collection

“…Similar observations were reported in a study involving 32 sesame genotypes from germplasm collections in Venezuela using AFLP markers (Laurentin and Karlovsky, 2006), 192 accessions of Ethiopian durum wheat using SNP markers (Alemu et al ., 2020), 139 Coix lacryma-jobi accessions in south-west China using AFLP (Fu et al ., 2019) and 190 Cypriot tomato germplasms using SSR markers (Athinodorou et al ., 2021). The observed clustering pattern could be due to fluted pumpkin breeding system or the existence of historical and current germplasm exchange among farming communities in the different regions (Ren et al ., 2015; McBenedict et al ., 2016; Alemu et al ., 2020). In Africa, farmer seed exchange is a widespread practice (Fayeun et al ., 2018).…”

“…As stated by McBenedict et al . (2016), famers in the communal areas of Zimbabwe source 80% of their seeds from neighbouring communities, while an estimated 60% travel long distances to buy or exchange propagules to maintain crop vigour. The landrace ToOg004, which originated from Cotonou in Benin Republic, but was collected in Idiroko in Ogun state, Nigeria clustered with other landraces of Nigerian origin.…”

“…The Shannon diversity index obtained in this study was less than 1.5. Shannon diversity index typically varies from 1.5 to 3.5 (McBenedict et al ., 2016). This result contradicts the fair level of diversity reported by Adeyemo and Tijani (2018) using RAPD markers.…”

African and Asian origin pearl millet populations: Genetic diversity pattern and its association with yield heterosis

“…• Introgression between African and Asian populations should continue to enhance productivity. Bashir et al, 2015;Diack et al, 2017;Hu et al, 2015;Jika et al, 2017;McBenedict, Chimwamurombe, Kwembeya, & Maggs-Kolling, 2016), and also in Asian landraces (Chowdari, Davierwala, Gupta, Ranjekar, & Govila, 1998;Vom Brocke, Christinck, Weltzien, Presterl, & Geiger, 2003). However, like other crops, the utilization of available germplasm is quite limited in the current pearl millet breeding programs (Serba et al, 2017;Yadav, Bidinger, & Singh, 2009;Yadav et al, 2017).…”

“…Recent characterization studies based on various agromorphological traits in pearl millet have reported significant variability among both African germplasm (Bashir, Ali, Ali, Melchinger, et al., 2014; Pucher et al., 2015; Sattler et al., 2018) and Asian germplasm (Kumari et al., 2016; Upadhyaya, Reddy, Ramachandran, Kumar, & Ahmed, 2016). Molecular marker‐based studies conducted to date have also reported significant diversity among African populations and landraces (Adeoti et al., 2017; Bashir et al., 2015; Diack et al., 2017; Hu et al., 2015; Jika et al., 2017; McBenedict, Chimwamurombe, Kwembeya, & Maggs‐Kolling, 2016), and also in Asian landraces (Chowdari, Davierwala, Gupta, Ranjekar, & Govila, 1998; Vom Brocke, Christinck, Weltzien, Presterl, & Geiger, 2003). However, like other crops, the utilization of available germplasm is quite limited in the current pearl millet breeding programs (Serba et al., 2017; Yadav, Bidinger, & Singh, 2009; Yadav et al., 2017).…”