Distant hybridization of Hemerocallis with Eremurus and Lycoris

ISHS Secretariat
Distant hybridization of Hemerocallis with Eremurus and Lycoris

Yi Lv is a Ph.D student at the School of Landscape Architecture, Beijing Forestry University, China, under the supervision of Prof. Yike Gao. Cooperating with her co-workers, Yi Lv has conducted distant hybridization breeding between Xanthorrhoeaceae and Amaryllidaceae. Distant hybridization is expected to result in new progenies with traits from genetically different species. This should enable plant producers to respond to new demands and global climate change. However, genetic differences between divergent species often result in strong reproductive isolation, making it very difficult to obtain progeny. To expand plant variation and to investigate the characteristics of distant hybrids, the team carried out a ten-year study of inter-generic and inter-family distant hybridization breeding research. Cooperating with the Hangzhou Botanical Garden, they chose Hemerocallis and Eremurus from the Xanthorrhoeaceae, and Lycoris and Clivia from the Amaryllidaceae as parental plants. A distant hybridization breeding system was established to increase the breeding efficiency and overcome reproductive isolation. After pollinating tens of thousands of flowers, they found that different floral sizes and flowering periods created an interaction barrier between stigma and pollen which triggered severe prezygotic isolation, and that different chromosome numbers triggered postzygotic isolation. Although the reproductive isolation was severe, through the use of artificial pollination treatments and embryo rescue, they obtained a few inter-family hybrids. The hybrids were identified by chromosome analysis and molecular markers. All of the hybrids are similar to the mother plants in yearly growth rhythm and morphological traits with slight variations but they do not show intermediate traits like traditional hybrids that are obtained by crossing between closely related plants. This study provides technical support for accelerating distant hybridization breeding and lays a foundation for the study of the variation characteristics of distant hybrids.

Yi Lv won the ISHS Young Minds Award for the best oral presentation at the XIV International Symposium on Flower Bulbs and Herbaceous Perennials in Poland in April 2024. The National Natural Science Foundation of China supported this research.

Yi Lv, School of Landscape Architecture, Beijing Forestry University, 100083 Beijing, China, e-mail: lvyi777@163.com

The article is available in Chronica Horticulturae

Tags: 
Hemerocallis
Eremurus
Lycoris
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Young Minds Award Winners