New insights into the range, morphology, and natural hybridization of wild Lactuca aculeata in Israel

Abstract

In recent years we initiated extensive studies on the characterization of the population structure of wild Lactuca relatives (WLRs) originating from their center of origin and diversity in Southwest Asia. The objectives of our research program are related to the identification, collection, distribution, conservation and sustainable use of these unique plant genetic resources (PGR) for breeding. Natural populations of Lactuca aculeata Boiss., a wild lettuce, closely related and fully inter-fertile with cultivated lettuce, sativa L., were identified throughout northeastern Israel. The collection includes 485 seed samples, which is likely the largest and most diverse collection of this important WLR. Seeds were collected from 46 locations, representing its ecogeographic distribution in northeastern Israel. Together with 14 additional observed localities, we recorded our observations from a total of 60 native locations of L. aculeata. Thus, we assume that northeastern Israel is an ecological domain where natural L. aculeata populations can be found. The analyzed data allowed us to specify the borders of the growing area in the region, as well as to describe the ecological features of the habitats and altitude distribution of natural L. aculeata within the studied area. Notably, our data included new findings of native locations of L. aculeata on the western side of the watershed in Israel. Selected morphological characteristics, from the regeneration of 185 samples, verified the identity of all except one as L. aculeata. Some progenies (0.27%) of the original collected plants were identified as hybrids of L. aculeata x L. serriola.