Screening Carica papaya × C. cauliflora hybrids for resistance to papaya ringspot virus‐type P

Abstract

Carica papaya, C. cauliflora and interspecific hybrids of these species were screened for resistance to two Australian isolates (338, 445) of papaya ringspot virus‐type P (PRSV‐P). Plants were manually inoculated with PRSV‐P in the glasshouse and the reaction assessed 30 days later by back‐inoculation to susceptible Cucurbita pepo and by a plate‐trapped antigen‐enzyme linked immunosorbent assay (PTA‐ELISA). Both parents and interspecific hybrids were also planted adjacent to infected C. papaya and 30 days later tested for PRSV‐P by PTA‐ELISA. All interspecific hybrid and C. cauliflora plants manually inoculated in the glasshouse or planted in the field failed to become infected, whereas C. papaya plants, in both situations, were infected by PRSV‐P. In addition, the surviving interspecific hybrid and C. cauliflora plants tested negative, while all C. papaya plants were positive for PRSV‐P in both the back‐inoculation and PTA‐ELISA tests. Thus, the interspecific hybrid and C. cauliflora plants were resistant to the Australian PRSV‐P isolates.

Screening of papaya accessions resistant to Papaya lethal yellowing virus and capacity of Tetranychus urticae to transmit the virus

“…Specifically for papaya, no resistance sources to the potyvirus PRSV, the causal agent of papaya ringspot, were reported (Magdalita et al, 1997;Dillon et al, 2005;O'Brien & Drew, 2009). Similarly, Nascimento et al (2012) found that all commercial varieties of squash (Cucurbita spp.)…”

Resistencia de Vasconcellea cauliflora al Virus de la mancha anular de la papaya-potyvirus (PRSV-P) y su introgresión en Carica papaya

“…Al compararse las secuencias genómicas evidenciaron diferencias estructurales y por lo tanto los productos proteicos presentarían una función diferenciada, lo cual estaría influyendo en la susceptibilidad o resistencia de las especies al virus. Magdalita et al (1997) realizaron cruzamientos de C. papaya x Vc y los embriones F 1 se rescataron pollination of papaya with Vc pollen. It has been stated that the optimum date to extract embryos from immature seeds is 90 days after pollination (Azad et al, 2014;Vegas et al, 2003).…”

“…When they compared their genomic sequences, they noted structural differences and, for this reason, the protein products may show a differentiated role, a fact that may influence the species susceptibility or resistance to the virus. Magdalita et al (1997) made C. papaya x Vc crosses and rescued in vitro F 1 embryos to develop hybrid individuals. The hybrid plants were artificially inoculated with two PRSV-P isolates from Australia.…”

An Analysis of Pollen Parameters, Fruit Set and Fruit Development During Attempts on Intergeneric Hybridization of Papaya (Carica papaya L.)

“…The Vasconcellea genera was earlier grouped with Carica genera only, but based on the chloroplast DNA characteristics, almost all the Carica species except C.papaya are now grouped under Vasconcellea [5]. Two wild relatives of papaya belonging now to Vasconcellea genera (V. cauliflora and V.candamrcensis) are known to possess resistance to PRSV by earlier workers [6][7][8]. The V. candamarcensis is also a possible genetic resource for improving cold tolerance in the cultivated varieties [9,6,10,11].…”