Assessment of genetic diversity among African cassava Manihot esculenta Grantz accessions resistant to the cassava mosaic virus disease using SSR markers

Abstract

A study was conducted to determine the extent of genetic diversity among African cassava (Manihot esculenta Crantz) accessions resistant to the cassava mosaic virus disease (CMD), using simple sequence repeat (SSR) markers. The accessions included a breeding stock (clone 58308), five improved lines, 62 CMD resistant and 10 CMD susceptible landraces. Genetic diversity was assessed among accessions in five cluster groups derived from UPGMA analysis on data from 18 SSR primer pairs. Average gene diversity, He, was high in all cluster groups, with an average heterozygosity of 0.591 ± 0.061. The estimator of inbreeding Fis revealed a low level of inbreeding within groups and averaged À0.262 ± 0.142. Gene diversity among all accessions was 51.4% and gene diversity within cluster groups was 46.6%, while 4.8% was due to diversity between the different cluster groups. The amount of genetic differentiation measured by Gst and Fst were 9.6% and 12.1% respectively, indicating a weak genetic structure.

Gene diversity and identification of putative hybridizing parents for root rot resistance in cassava using simple sequence repeats

“…The mean value of Ĥe, 0.754, obtained in the present study is higher than the mean value of 0.57 obtained for collections in regions of Brazil (Siqueira et al, 2009); 0.477 for African landraces (Lokko et al, 2006); and 0.535 for African and Neotropical countries (Fregene et al, 2003). This higher diversity obtained in the present study may be attributed to the diverse exotic sources of the 43 improved genotypes.…”

Genetic diversity and population structure of traditional sweet cassava accessions from Southern of Minas Gerais State, Brazil, using microsatellite markers

“…Similar results were obtained by Costa et al (2013) and Ortiz et al (2016) when these authors analyzed traditional sweet cassava accessions from Paraná State. This fact emphasizes the influence of exchanging cassava germplasm among cassava producers, upon population structure: accesses that were grown in different and distant regions were clustered in the same group (Lokko et al, 2006;Kizito et al, 2007, Ortiz et al, 2016.…”

“…Similar results of Fst index (0.07) were found by Ferreira et al (2015), when the authors analyzed the genetic diversity of landraces of sweet cassava from the Mato Grosso do Sul State. Lokko et al (2006) conducted studies of the genetic diversity in cassava accessions resistant to CMV (cassava mosaic virus). The authors found a values of Fst index that were considered low, while Ortiz et al (2016) accessions of cassava from Maringá, Cianorte and Toledo, Parana state, verified a moderate diversity between the two groups of cassava accessions originally from Maringá, Paraná State (Fst index = 0.107).…”

Diversidade genética de variedades tradicionais de mandioca (Manihot esculenta Crantz) cultivada em comunidades da Baixada Cuiabana em Mato Grosso por meio de microssatélites

“…Esses microtubos foram acondicionados em isopores e transportados ao Laboratório LEEGA para as análises. , LOKKO et al, 2006, KIZITO et al, 2007, SIQUEIRA et al, 2009, SIQUEIRA et al, 2010. 3.6 Eletroforese do produto amplificado…”