Multiple haploids, triploids, and tetraploids found in modern-day "living fossil" Ginkgo biloba. Issue 1 (1st October 2018)

• Record Type: Journal Article
• Authors: Šmarda, Petr; Horová, Lucie; Knápek, Ondřej; Dieck, Heidi; Dieck, Martin; Ražná, Katarína; Hrubík, Pavel; Orlóci, Laszlo; Papp, Laszlo; Veselá, Kristýna; Veselý, Pavel; Bureš, Petr
• Is Part Of: Horticulture research. Volume 5:Issue 1(2018)
• Publication Date: 2018-10-01
• Subjects: Natural variation in plants -- Plant breeding -- Plant evolution -- Polyploidy in plants; Horticulture -- Research -- Periodicals; 635.072
• DOI: 10.1038/s41438-018-0055-9
• Languages: English
• ISSNs: 2052-7276

Abstract

Abstract: Ginkgo biloba, the last extant representative of a lineage of Mesozoic gymnosperms, is one of the few seed plants with an exceptionally long (~300 Myr) evolutionary history free of genome-wide duplications (polyploidy). Despite this genome conservatism, we have recently found a viable spontaneous tetraploid Ginkgo sapling during routine screening of several plants, demonstrating that natural polyploidy is possible in Ginkgo . Here we provide a much wider flow cytometry survey of ploidy in some European Ginkgo collections, and own seedlings (>2200 individuals and ~200 cultivars). We found a surprisingly high level of ploidy variation in modern-day Ginkgo and documented altogether 13 haploid, 3 triploid, and 10 tetraploid Ginkgo plants or cultivars, most of them being morphologically distinct from common diploids. Haploids frequently produced polyploid (dihaploid) buds or branches. Tetraploids showed some genome size variation. The surveyed plants provide a unique resource for future Ginkgo research and breeding, and they might be used to accelerate the modern diversification of this nearly extinct plant lineage. Genetics: Mutant Ginkgos occur with surprising frequency: The genetic abnormality, polyploidy, which underlies some unusual varieties of Ginkgo biloba, is more common than previously thought. Genome-wide duplications called polyploidies occur repeatedly in the evolution seed plants. The ancient Ginkgo tree, widely cultivated for its esthetic and medicinal properties, is one of the few seed plant species with a very long polyploidy-free evolutionary history. Yet, when Petr Smarda, of Masaryk University, in Brno, Czech Republic, and colleagues screened more than 2200 Ginkgo individuals and around 200 cultivars, they found 13 haploids, 3 triploids, and 10 tetraploids. These had unusual characteristics such as being shorter than normal and having especially small or large leaves. Improved understanding of the genetic mutations underlying these varieties could facilitate efforts to preserve them and help accelerate diversification of this ancient and nearly extinct plant lineage.