Juniper dwarf mistletoe (Arceuthobium oxycedri) in the Crimean Peninsula: novel insights into its morphology, hosts, and distribution

摘要

Juniper dwarf mistletoe (Arceuthobium oxycedri (DC.) M. Bieb) is a semiparasitic species of Holarctic Cupressaceae hosts. This study updates the status of A. oxycedri and its hosts at the Crimean Peninsula, clearly defining them as principal (Eastern prickly juniper, Juniperus deltoides R.P. Adams), secondary (Greek juniper, J. excelsa M. Bieb.), occasional (rare) (Oriental thuja, Platycladus orientalis (L.) Franco), and uncommon (other representatives of Juniperus, Cupressus, and Chamaecyparis genera). Using eight morphological characteristics (aerial shoot length, basal diameter, 1st/2nd/3rd internode lengths and widths), we investigated aerial shoot morphology of male and female A. oxycedri plants on three hosts and found host-dependent differences. Parasites on P. orientalis, a nonprincipal host, at different sites are smaller by comparison with both juniper hosts. Anthesis, fruit ripening, and seed release are host-dependent as well. Two fly species (Diptera), common greenbottle (Lucilia ceasar L.), and dronefly (Eristalis tenax L.), were observed at peak of anthesis on male A. oxycedri inflorescences, suggesting they are involved in pollination. To our knowledge, we are presenting the first detailed study A. oxycedri distribution patterns in the Crimea, which appear to coincide with the range of J. deltoides at around 100 sites.