Lactuca georgica, a new wild source of resistance to downy mildew: comparative study to other wild lettuce relatives

Research output: Contribution to journalArticlepeer-review

Abstract

Seedlings of 431 accessions representing six and five Armenian natural populations of the wild Lactuca georgica and L. altaica, respectively, and 32, 23, and 20 populations of L. saligna, L. serriola, and L. aculeata, respectively (mostly Israeli natural populations), were screened at seedling stage for resistance to six highly virulent races of Bremia lactucae - the causal of lettuce downy mildew - that were found on several widely grown cultivars and represent the virulence spectrum in the main lettuce production areas in Europe and California. This study is likely the first detailed screening of resistance to B. lactucae races in natural populations of L. georgica and L. altaica. The highest average resistance probability and frequency of highly resistant accessions across races were detected in L. georgica. These were even higher than those shown by the germplasm of known non-host resistance (NHR) species L. saligna, which classified to the secondary lettuce gene pool (LGP-2). Thus, we suggest that L. georgica is a new LGP-2 source of resistance to B. lactucae. Our findings also support previous observations that L. aculeata, a species within the LGP-1, should be prioritized as a source of downy mildew resistance in domesticated lettuce (L. sativa) breeding programs, since some L. aculeata accessions expressed highly resistance across races. For L. serriola, the closest relative of cultivated lettuce, and for L. altaica, also a closer or even a primitive form of L. sativa, probabilities of resistance to each of the investigated B. lactucae races were very low.

Original languageEnglish
Pages (from-to)127-136
Number of pages10
JournalEuropean Journal of Plant Pathology
Volume160
Issue number1
DOIs
StatePublished - May 2021

Bibliographical note

Funding Information:
AB wishes to thank Rijk Zwaan (De Lier, The Netherlands) for providing greenhouse facilities, support in assessment and cultivation of the Lactuca accessions, as well as screening for resistance to the B. lactucae races. Financial support by the Research Authority, and performing the statistical analysis by Mrs. Efrat Yaskil, the Statistics Consulting Unit, University of Haifa, Israel, are acknowledged. Valuable comments on the revised version of this manuscript by Dr. Roi Ben-David, Institute of Plant Sciences, Agriculture Research Organization (ARO), Volcani Center, Bet Dagan, Israel, are gratefully acknowledged.

Funding Information:
AB wishes to thank Rijk Zwaan (De Lier, The Netherlands) for providing greenhouse facilities, support in assessment and cultivation of the Lactuca accessions, as well as screening for resistance to the B. lactucae races. Financial support by the Research Authority, and performing the statistical analysis by Mrs. Efrat Yaskil, the Statistics Consulting Unit, University of Haifa, Israel, are acknowledged. Valuable comments on the revised version of this manuscript by Dr. Roi Ben-David, Institute of Plant Sciences, Agriculture Research Organization (ARO), Volcani Center, Bet Dagan, Israel, are gratefully acknowledged.

Publisher Copyright:
© 2021, Koninklijke Nederlandse Planteziektenkundige Vereniging.

Keywords

  • Bremia lactucae
  • Gene pools
  • Lettuce breeding
  • Non-host resistance
  • Wild Lactuca species

ASJC Scopus subject areas

  • Agronomy and Crop Science
  • Plant Science
  • Horticulture

Fingerprint

Dive into the research topics of 'Lactuca georgica, a new wild source of resistance to downy mildew: comparative study to other wild lettuce relatives'. Together they form a unique fingerprint.

Cite this