Determination of genome size variation among varieties of Ilex cornuta (Aquifoliaceae) by fow cytometry
From Firenze University Press Journal: Caryologia
Peng Zhou, Jiangsu Academy of Forestry
Jiao Li, Co‑Innovation Center for Sustainable Forestry in Southern China, Key Laboratory of State Forestry and Grassland Administration on Subtropical Forest Biodiversity Conservation, College of Biology and the Environment, Nanjing Forestry University
Jing Huang, Jiangsu Academy of Forestry
Fei Li, Jiangsu Academy of Forestry
Qiang Zhang, Co‑Innovation Center for Sustainable Forestry in Southern China, Key Laboratory of State Forestry and Grassland Administration on Subtropical Forest Biodiversity Conservation, College of Biology and the Environment, Nanjing Forestry University
Min Zhang, Jiangsu Academy of Forestry
The Ilex L. (holly) is the only living woody dioecious angiosperm genus, accounting for approximately 600 species with a broad distribution from tropics to temperate regions within the monogeneric family of Aquifoliaceae (Loizeau et al. 2016). The Ilex species are prized for their glossy evergreen foliage and abundant showy fruits that can bloom from autumn to early spring, when many other plants in the landscape are dormant (Yao et al. 2021).
Ilexcornuta Lindl. & Paxton, one of very important native landscape woody materials and distributed only in eastern China and Korea (Hu 1949), has been utilized as a horticultural species because its leaves are distinctive rectangular foliage (one or two spines per side) and its fruits are red berries (Park et al. 2019). I.cornuta, the most spe-ciose and commercially significant specie of the diverse genus Ilex, has a long and complex horticultural his-tory. Together with I.aquiforlium usually distributed in Europe, it is a typical species for Christmas tree inside home. In addition, it has been utilized as medical plant in China so that it contains several useful compounds (Zhang et al. 2012; Kang et al. 2014). Extensive cultiva-tion and hybridization have produced many varieties of I.cornuta, including commercially important horticul-tural species such as cultivated tea and iconic flowering shrubs (Hodges et al. 2001; Park et al. 2019).Genome size (C value/haploid nuclear DNA content) is an important attributes of living organisms, which is correlated with size of nucleus/cell, cellular process including DNA synthesis rate and ecological traits, etc.
Genome size has fundamental significance in a wide range of applications including molecular biology, ecology, systematic biology, cytology, evolutionary biology and genomics (Jatt et al. 2019). Genome sizes of more than 7500 plant species have been estimated (Bennett and Leitch 2012), but the genome sizes of higher spe-cies are still poorly understood (Bennett and Leitch 2011; Doležel and Bartoš 2005). Flow cytometric analysis in plants has proved to be useful to determine DNA con-tent and ploidy level in different species and accessions (Sliwinska 2018; Pellicer et al. 2014; D’hondt et al. 2011).The genus Ilex is one of the largest plant genera, but of which only 6 species of genome size have been deter-mined (Bennett and Leitch 2012). As the most speciose member of this genus, I.cornuta has become widely cul-tivated throughout Asia, Europe and America. Despite the considerable breeding, selection, widespread cul-tivation and domestication of I.cornuta, which may have a significant role in the composition of genomes, except for I.cornuta (Zhang et al. 2013), there are no other previous reports of intraspecific genome size vari-ation in the different cultivars or hybrids of this species.
Improved knowledge of genome size of key cultivars and complex hybrids would be a valuable resource for fur-ther breeding and improvement of I.cornuta. Therefore, in this study, the genome size of cultivars and hybrids of I.cornuta were identified and analyzed by FCM. The genome size variation of different I.cornuta varieties were explored to provide a basis for the development and utilization of I.cornuta germplasm resources.
DOI: https://doi.org/10.36253/caryologia-1902
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