Genetic diversity of tropical maize inbred lines combining resistance to Striga hermonthica with drought tolerance using SNP markers

Abstract

Striga hermonthica and drought are the major stresses limiting maize yields in sub‐Saharan Africa. The search for diverse maize lines’ tolerance to drought and resistance to S. hermonthica (DTSTHR) is very crucial for yield improvement in areas affected by the two stresses. Understanding the genetic diversity among the lines is important to develop cultivars resistant to S. hermonthica and tolerant to drought. The lines were developed from biparental crosses of drought‐tolerant and Striga‐resistant lines. A total of 128 DTSTHR maize lines were characterized using single‐nucleotide polymorphism (SNP) markers. Results of the cluster analysis based on 3297 SNP markers showed four distinct groups consistent with the pedigrees of the lines. Furthermore, model‐based analysis also formed the same groups of the DTSTHR lines. Integrating the pedigree information with combining ability and the SNP analyses may provide defined heterotic groups for maize improvement work in West and Central Africa. These results also help breeders to utilize DTSTHR lines present at IITA for developing biparental crosses without disrupting the heterotic groups they have established in their breeding programmes.

Genetic diversity and path analysis for nitrogen use efficiency of tropical popcorn (Zea mays ssp. everta) inbred lines in adult stage

“…The diversity analysis clustered the most tolerant inbred lines together and was consistent with pedigree records, as observed by Mengesha et al. () and Oyekunle, Badu‐Apraku, Hearne, and Franco () for drought tolerance and Striga hermonthica resistance in tropical maize.…”

Recent research progress in combatting root parasitic weeds

“…Heterotic grouping among 378 hybrids derived from diallel crosses of 28 early inbreds were evaluated in S. hermonthica-infested and S. hermonthica-free environments using SSR markers, to utilize the information in a maize hybrid breeding programme [42]. Very recently, the genetic diversity of tropical maize inbred lines combining resistance to S. hermonthica with drought tolerance was exhibited using SNP markers [43]. The effectiveness of marker-assisted recurrent selection to improve S. hermonthica resistance together with drought tolerance in maize breeding was demonstrated [44].…”

An Integrated Molecular and Conventional Breeding Scheme for Enhancing Genetic Gain in Maize in Africa

“…For instance, Striga tolerance is combined with drought tolerance (Mengesha et al, 2017), drought tolerance with heat tolerance (Meseka et al, 2018), or drought tolerance with low soil nitrogen tolerance (Ajala et al, 2019; Badu-Apraku and Akinwale 2011). Assessments of the genetic diversity of 128 lines that can tolerate drought and Striga that were conducted using single nucleotide polymorphism (SNP) markers have enabled the identification of suitable inbred lines for hybrid combinations based on genetic diversity (Mengesha et al, 2017). On the other hand, the integration of pedigree information with combining ability and genotypic analysis allows for more accurate definitions of heterotic groups (Badu-Apraku et al, 2016b).…”