AFLP-Based Genetic Diversity and Its Comparison with Diversity Based on SSR, SAMPL, and Phenotypic Traits in Bread Wheat

Abstract

Data on AFLP (eight primer pairs) and 14 phenotypic traits, collected on 55 elite and exotic bread wheat genotypes, were utilized for estimations of genetic diversity. We earlier used these 55 genotypes for a similar study using SSRs and SAMPL. As many as 615 scorable AFLP bands visualized included 287 (46.6%) polymorphic bands. The phenotypic traits included yield and its component traits, as well as physiomorphological traits like flag leaf area. Dendrograms were prepared using cluster analysis based on Jaccard's similarity coefficients in case of AFLP and on squared Euclidean distances in case of phenotypic traits. PCA was conducted using AFLP data and a PCA plot was prepared, which was compared with clustering patterns in two dendrograms, one each for AFLP and phenotypic traits. The results were also compared with published results that included studies conducted elsewhere using entirely different wheat germplasm and our own SSR and SAMPL studies based on the same 55 genotypes used in the present study. It was shown that molecular markers are superior to phenotypic traits and that AFLP and SAMPL are superior to other molecular markers for estimation of genetic diversity. On the basis of AFLP analysis and keeping in view the yield performance and stability, a pair of genotypes (E3876 and E677) was recommended for hybridization in order to develop superior cultivars.

Morphological, pedigree, and molecular distances and their association with hybrid wheat performance

“…A study based on 200 polymorphic bands obtained from fi ve AFLP primer combinations was reported (Corbellini et al, 2002). However, polymorphism levels as low as 47% have also been detected in wheat (Roy et al, 2004). These reports confi rm that AFLP markers can be effi ciently used to detect genetic variability in wheat.…”

“…Some studies on wheat have reported the association between hybrid performance and morphological (Cruz et al, 2004), molecular (Roy et al, 2004), combined morphological and molecular (Franco et al, 2001;Vieira et al, 2007), and pedigree-based distances (Almanza-Pinzón et al, 2003). Such tools are important auxiliary techniques for the selection of the best parental combinations and for a more rational use of germplasm.…”

“…However, many studies indicate that the usefulness of such distance measures in selecting parental genotypes may be related to the genotype pool and the number of traits evaluated, as well as to the cultivation environment, and genotype x environment (GXE) interactions (Corbellini et al, 2002;Bertan et al, 2007;Vieira et al, 2007). Roy et al (2004) reported that the correlation between genetic distances estimated for wheat, using amplifi ed fragment length polymorphism (AFLP) markers and 14 morphological characters, was 0.072, indicating an association close to null. Máric et al (2004) reported a small correlation (r = 0.12) between distances estimated using random amplifi ed polymorphic DNA (RAPD) markers and 12 morphological characters.…”

Genetic Divergence in Wheat (Triticum aestivum L.Thell.) Under Saline Sodic Condition

“…The grouping of genotypes reveled that indentified tolerant genotypes may be used as donor in various hybridization programmes to improve yield under sodic soil created saline stress environment. Earlier studied have also reported substantial genetic divergence in wheat (Deshmukh et al, 1999;Roy et al, 2004;Verma et al, 2006;Singh et al, 2006;Iqubal et al, 2007). The cluster pattern of the genotypes showed non-parallelism between geographic and genetic diversity (Singh et al, 2009).…”

“…Earlier studied have also reported substantial genetic divergence in wheat (Deshmukh et al, 1999;Roy et al, 2004;Verma et al, 2006;Singh et al, 2006;Iqubal et al, 2007). The grouping of genotypes reveled that indentified tolerant genotypes may be used as donor in various hybridization programmes to improve yield under sodic soil created saline stress environment.…”