ARS | Publication request: A GENETIC MAP OF CUCUMBER COMPOSED OF RAPDS, RFLPS, AFLP MARKERS AND LOCI CONDITIONING RESISTANCE TO PAPAYA RINGSPOT AND ZUCCHINI YELLOW MOSAIC VIRUSES

Submitted to: Genome Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 22, 2000
Publication Date: N/A

Interpretive Summary: The watermelon strain of papaya ringspot virus (PRSV-W) and zucchini yellow mosaic virus (ZYMV) incite significant losses in cucumber. Resistances to both of these viruses have been identified in foreign cucumber populations. Because virus inoculations are time consuming and labor intensive, we identified differences in the DNA that distinguish among plants that are resistant and susceptible to these two viruses. We found that the genes conditioning resistances to PRSV-W and ZYMV are located very close to each other, meaning that resistances tend to be inherited together. One DNA difference was found that was always inherited with resistance to ZYMV. This DNA difference can be used by the seed industry to more efficiently identify resistant plants, avoiding the maintenance of the viruses and labor- intensive inoculations.

Technical Abstract: The watermelon strain of papaya ringspot virus (PRSV-W) and zucchini yellow mosaic virus (ZYMV) are potyviruses that incite significant losses in cucumber. Resistances have been identified primarily in exotic germplasms that require transfer to elite cultivated backgrounds. To select more efficiently for virus resistances, we identified molecular markers tightly linked to PRSV-W and ZYMV resistances in cucumber. We generated F6 recombinant inbred lines from a cross between Straight 8 and TMG1 (susceptible and resistant, respectively, to both viruses) and studied the segregations of amplified fragment length polymorphisms (AFLPs), randomly amplified polymorphic DNAs (RAPDs), restriction fragment length polymorphisms (RFLPs), and resistances to PRSV-W and ZYMV. A 353-point map of cucumber was generated delineating 12 linkage groups at LOD 3.5. Linkage arrangements among RFLPs were consistent with previously published maps; however linkages among RAPDs in our map did not agree with a previously published map. Resistances to PRSV-W and ZYMV were tightly linked (2.2 cM) and mapped to the end of one linkage group. One AFLP cosegregated with resistance to ZYMV.