Selection of Simple Sequence Repeat Markers Associated with Inheritance of Sweetpotato Virus Disease Resistance in Sweetpotato

Abstract

Sweetpotato virus disease (SPVD), a complex of Sweet potato chlorotic stunt virus (SPCSV; Crinivirus) and Sweet potato feathery mottle virus (SPFMV; Potyvirus) causes high yield losses in sub‐Saharan Africa (SSA). The development of resistant cultivars to SPVD has been limited by the complex sweetpotato [Ipomoea batatas (L.) Lam. var. batatas] genetics and high levels of mutations in the causal viruses. The objectives of this study were to understand the inheritance of SPVD resistance and identify simple‐sequence repeat (SSR) markers associated with its resistance in a biparental sweetpotato mapping population. A total of 287 progeny and parents of the ‘New Kawogo’ × ‘Beauregard’ population were genotyped with 250 SSR markers and phenotyped for SPVD resistance at three sites and two seasons in Uganda. The broad‐sense heritability for SPVD resistance was 0.51. Two progeny showed positive transgressive segregation for overall genotype mean SPVD severity across sites and seasons. A total of seven SSR markers were significantly associated with SPVD resistance in this population. These markers and other SSRs need to be used to fine map the quantitative trait loci (QTL) of SPVD resistance for future implementation of marker‐assisted selection (MAS) for SPVD resistance in sweetpotato.

Multiple QTL Mapping in Autopolyploids: A Random-Effect Model Approach with Application in a Hexaploid Sweetpotato Full-Sib Population

“…A recent map was developed from a selfing population and used only single-dose SNPs, resulting in higher marker saturation in comparison to the previous maps (Shirasawa et al 2017), though the map was still not integrated. In some of these cases, QTL mapping analyses were performed for several traits, related mostly to quality (Cervantes-Flores et al 2011;Zhao et al 2013;Yu et al 2014;Kim et al 2017) and resistance to biotic stresses (Cervantes-Flores et al 2008b;Yada et al 2017a). For yield-related traits, only two studies have been reported to date (Chang et al 2009;Li et al 2014).…”

Breeding Progress for Vitamin A, Iron and Zinc Biofortification, Drought Tolerance, and Sweetpotato Virus Disease Resistance in Sweetpotato

“…Field screening is problematic because vector populations fluctuate over seasons and years (Aritua et al, 1998;Clark et al, 2012) and roots are available only after completing a first seedling generation. Typically, large (50,000-100,000) populations of F 1 seedlings require testing for several seasons for several years to identify agronomically superior genotypes with true SPVD resistance (Mwanga et al, 2013;Yada et al, 2017b). Initially, plants may escape infection, taking three or more years to show SPVD symptoms.…”

In silico prediction and segregation analysis of putative virus defense genes based on SSR markers in sweet potato F1 progenies of cultivars New Kawogo and Resisto

“…In the present study, the detection of microsatellites (SSR markers) within the DNA coding regions of the defense genes indicates an improvement in understanding of defense genes and virus resistance compared with previous knowledge (Mwanga et al, 2002;Yada et al, 2017). It is important to note that the sweet potato SSRs currently known (Parado, 2010;Wang et al, 2011) are randomly located within the genome and tend to be difficult to develop or study without the use of sophisticated equipment (Schafleitner et al, 2010;Wang et al 2011); however, the method used in the present is inexpensive and targeted to specific genes and chromosomes.…”