Intraspecific, Interspecific, and Interseries Cross-compatibility in Lilac

Abstract

<jats:p>Lilacs (<jats:italic>Syringa</jats:italic> sp.) are a group of ornamental trees and shrubs in the Oleaceae composed of 22–30 species from two centers of diversity: the highlands of East Asia and the Balkan-Carpathian region of Europe. There are six series within the genus <jats:italic>Syringa</jats:italic>: <jats:italic>Pubescentes</jats:italic>, <jats:italic>Villosae</jats:italic>, <jats:italic>Ligustrae</jats:italic>, <jats:italic>Ligustrina</jats:italic>, <jats:italic>Pinnatifoliae</jats:italic>, and <jats:italic>Syringa</jats:italic>. Intraspecific and interspecific hybridization are proven methods for cultivar development. However, reports of interseries hybridization are rare and limited to crosses among taxa in series <jats:italic>Syringa</jats:italic> and <jats:italic>Pinnatifoliae</jats:italic>. Although hundreds of lilac cultivars have been introduced, fertility and cross-compatibility have yet to be formally investigated. Over 3 years, a cross-compatibility study was performed using cultivars and species of shrub-form lilacs in series <jats:italic>Syringa</jats:italic>, <jats:italic>Pubescentes</jats:italic>, and <jats:italic>Villosae</jats:italic>. A total of 114 combinations were performed at an average of 243 ± 27 flowers pollinated per combination. For each combination, we recorded the number of inflorescences and flowers pollinated as well as number of capsules, seed, seedlings germinated, and albino seedlings. Fruit and seed were produced from interseries crosses, but no seedlings were recovered. A total of 2177 viable seedlings were recovered from interspecific and intraspecific combinations in series <jats:italic>Syringa</jats:italic>, <jats:italic>Pubescentes</jats:italic>, and <jats:italic>Villosae</jats:italic>. Albino progeny were produced only from crosses with <jats:italic>Syringa pubescens</jats:italic> ssp. <jats:italic>patula</jats:italic> ‘Miss Kim’. In vitro germination was attempted on 161 seed from interseries crosses, resulting in three germinations from <jats:italic>S. pubescens</jats:italic> Bloomerang<jats:sup>®</jats:sup> x <jats:italic>Syringa vulgaris</jats:italic> ‘Ludwig Spaeth’. None survived, yet cotyledons produced callus for future efforts to induce embryogenic shoots. This study is a comprehensive investigation of lilac hybridization, and the knowledge gained will aid future efforts in lilac cultivar development.</jats:p>

Sowing Green Seed Without Stratification Does Not Shorten Juvenility or Increase Plant Size in Common Lilac (Syringa vulgaris)

“…Plant materials. In Spring 2015, two lilac cultivars were selected based on their crosscompatibility reported by a previous study (Lattier and Contreras, 2017). Syringa vulgaris 'Ludwig Spaeth' (10-0042) and S. vulgaris 'Angel White' (10-0043) were acquired from Blue Heron Farms in Corvallis, OR.…”

“…In a previous study of cross-compatibility among lilac cultivars (Lattier and Contreras, 2017), germinated seedlings from coldstratified seed were observed to have a quiescent phase during their first year when vegetative growth was limited, but the seedling developed a large root system (Fig. 1A).…”

Morphological and molecular data support the separate species status of Syringa fauriei in Korea

“…The tribe Oleeae is clearly monophyletic, comprising the subtribes Ligustrinae ( Syringa and Ligustrum ). There are 22–30 species of Syringa from two distinct centers of diversity: the highlands of East Asia and the Balkan‐Carpathian region of Europe (Kochieva et al 2004, Lattier and Contreras 2017). Only two species, S. vulgaris and S. josikaea , are distributed in southeastern Europe and are disjunct from the majority of their Northeast Asian counterparts (Green 1972, Kim and Jansen 1998).…”

Identification of Corynespora cassiicola causing leaf spot on Syringa species

“…), in the Oleaceae, comprise approximately 30 species of deciduous shrubs or small trees, that are native to temperate Asia and southeastern Europe (Li et al, 2002). They are widely cultivated as ornamentals, producing beautiful, fragrant flowers in spring (Kochneva et al, 2004; Lattier & Contreras, 2017). However, lilacs are often seriously damaged by insects and microorganisms, which can reduce the ornamental value when severely affected (Mmbaga et al, 2011).…”