ISHS Acta Horticulturae 634: XXVI International Horticultural Congress: IV International Symposium on Taxonomy of Cultivated Plants
TAXONOMIC RECONSIDERATION OF SOME LACTUCA SPP. GERMPLASM MAINTAINED IN WORLD GENEBANK COLLECTIONS |
| Authors: | I. Dolezalová, A. Lebeda, I. Tiefenbachová, E. Křistková |
| Keywords: | genetic resources, isozyme polymorphism, morphology, reference herbarium specimens, taxonomic revision, wild lettuce |
| Abstract:
In total 49 accessions of 24 wild Lactuca spp., a hybrid between L. serriola x L. sativa and the related species Mycelis muralis were evaluated with the aim to validate their taxonomic status. Based on morphological and other characters (e.g. chromosome number, relative DNA content, isozymes polymorphism) 17 germplasm accessions were reclassified. The majority of these 17 accessions was classified to the species L. serriola and as primitive forms of L. sativa. The taxonomic status of the other questionable Lactuca accessions is discussed in relation to their morphology. It was found after taxonomic revision, that the genetic variability of the genus Lactuca maintained in the genebank collection, represents 18 wild Lactuca species and cultivated L. sativa. Due to absence of passport data and reference herbarium material, the generic name Lactuca sp. was used for two accessions. The species L. alpina (L.) Gray, L. dentata L. (Thunb.) Robins., L. denticulata (Houtt.) Maxim., L. homblei De Wild., L. livida Boiss. & Reut., L. quercina L. and L. squarrosa (Thunb.) Miq. (syn L. indica L.) reported previously in the Czech National Germplasm Collection are not present. It was not possible to identify the accession named as L. homblei unambiguously because of a lack of available reference herbarium specimens. Preliminary conclusions suggest, it may be L. schweinfurthii Oliv. & Hiern or L. logenspicata De Wild. Lactuca angustana was treated as L. sativa L. var. angustana Irish. The accession classified previously to the genus Lactuca is actually Sonchus oleraceus and was excluded from Lactuca collection. | |
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