Development of a codominant CAPS marker linked to PRSV-P resistance in highland papaya

Abstract

Development of resistant papaya varieties is widely considered the best strategy for long-term control of the papaya ringspot virus type P (PRSV-P). Several species of "highland papaya" from the related genus Vasconcellea exhibit complete resistance to PRSV-P, and present a valuable source of resistance genes with potential for application in Carica papaya. The objectives of this study were two fold; to identify molecular markers linked to a previously characterised PRSV-P resistance gene in V. cundinamarcensis (psrv-1), and to develop codominant marker based strategies for reliable selection of PRSV-P resistant genotypes. Using a bulked segregant analysis approach, dominant randomly amplified DNA fingerprint (RAF) markers linked to prsv-1 were revealed in the resistant DNA bulk, which comprised F2 progeny from a V. parviflora (susceptible) x V. cundinamarcensis (resistant) interspecific cross. One marker, Opk4_1r, mapped adjacent to the prsv-1 locus at 5.4 cM, while a second, Opa11_5r, collocated with it. Sequence characterisation of the Opk4_1r marker permitted its conversion into a codominant CAPS marker (PsiIk4), diagnostic for the resistant genotype based on digestion with the restriction endonuclease PsiI. This marker mapped within 2 cM of the prsv-1 locus. Psilk4 was shown to correctly identify resistant genotypes 99% of the time when applied to interspecific F2 progeny segregating for the resistant character, and has potential for application in breeding programs aimed to deliver the PRSV-P resistance gene from V. cundinamarcensis into C. papaya.

Isolation and Characterisation of PRSV-P Resistance Genes inCaricaandVasconcellea

“…Alternative splicing predicted in this study is strongly supported by the result of [8] who found another marker, Opk4_1r, that was close to the prsv-1 resistance gene in V. pubescens but not in C. papaya . Opk4_1r has homology to a gene that codes for a small nuclear ribonuclear class of protein (snRNP) which has a motif known as a RNA binding domain (RBD) or ribonucleoprotein (RNP).…”

“…Dillon [8] characterized the Opa11_5r marker in six Vasconcellea species ( V. pubescens , V. stipulata , V. goudotiana , V. cauliflora , V. parviflora, and V. quercifolia ) as well as in C. papaya genotype 2.001. The marker had homology to a serine threonine protein kinase (STK).…”

Development of CAPS markers to identify Indian tea (Camellia sinensis) clones with high catechin content

“…However, with increased availability of specific gene sequences in publically available global databases, markers targeting specific genes are becoming more reliable and popular. Markers such as cleaved amplified polymorphic sequence (CAPS) (Konieczny and Ausubel, 1993) or amplicon restriction pattern (ARP) (Yanthan and Misra, 2013) have been employed for marker-assisted selection in many plant species (Chauhan and Misra, 2002;Dillon et al, 2006;Gutierrez et al, 2006;Kuklev et al, 2009;Ben et al, 2015). This technique involves amplification of the DNA by polymerase chain reaction (PCR) followed by digestion of the PCR product or amplicon with different restriction enzymes.…”

Differential Gene Expression in Response to Papaya ringspot virus Infection in Cucumis metuliferus Using cDNA- Amplified Fragment Length Polymorphism Analysis

“…The polyprotein is then cleaved into the following mature proteins: VPg, P1, HC-Pro, P3, CI, 6K, NIa, NIb and CP [12]. Control of PRSV diseases in papaya has been focused on developing tolerant or resistant varieties; these varieties are rarely planted because of poor fruit quality and vigor [13], [14]. The cross protection strategy of inoculating papaya with a mild strain of PRSV (HA 5-1 or HA 6-1) provides resistance against severe PRSV strain infection in Taiwan [15], [16].…”