Molecular, morphological and palynological assessment of hemerocallis core collection

Authors: LI, SEN - Shanxi Agriculture University; JI, FANGFANG - Shanxi Agriculture University; HOU, FEIFAN - Shanxi Agriculture University; SHI, QINGQING - Shanxi Agriculture University; XING, GUOMING - Shanxi Agriculture University; CHEN, HONG - Shanxi University; Weng, Yiqun; KANG, XIUPING - Shanxi Agriculture University

Submitted to: Scientia Horticulturae
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/2/2021
Publication Date: 4/29/2021
Citation: Li, S., Ji, F., Hou, F., Shi, Q., Xing, G., Chen, H., Weng, Y., Kang, X. 2021. Molecular, morphological and palynological assessment of hemerocallis core collection. Scientia Horticulturae. 285. Article 110181. https://doi.org/10.1016/j.scienta.2021.110181.
DOI: https://doi.org/10.1016/j.scienta.2021.110181

Interpretive Summary: The night and day lilies in the genus Hemerocallis are an economically important specialty crops widely grown in many countries with ornamental and food uses. Both are also becoming model plants for understanding of some interesting biological phenomena such as strict flowering rhythm and rapid withering after flower opening. However, little is known on the genetic diversity of germplasm collection of the night and day lilies, making it difficult for efficient management of use in breeding. In this study, from 155 Hemerocallis accessions, a core collection with 32 accessions was developed using both molecular and morphological markers and a stepwise sampling strategy. The genetic diversity in the 32 accessions of the core collection is highly representative of the original population. The molecular data and morphological data provided equal power in assessing the genetic diversity of the core collection, use of pollen morphology has its limitations for the study of the genetic relationships within Hemerocallis. The 32 accessions could be broadly classified into two groups: night lily and day lily. The molecular data support that the night lily was selected from the day lily which has higher degree of genetic diversity. However, there is extensive phenotypic diversity for yield and other horticulturally important traits in this core collection that is useful for night lily improvement. This work provides insights into the genetic diversity of night and day lily collections. The core collection helps more efficient management of the germplasm collection and its use in night and daily breeding.

Technical Abstract: The night lily, Hemerocallis citrina Baroni, is an economically important specialty crop widely grown in East Asia. It is mainly consumed as a vegetable for the dried flower buds, and is also for medicinal use. Hemerocallis spp. is becoming a model plant for understanding of several interesting biological phenomena in biology, such as self-incompatibility, circadian rhythm and programmed cell death system. Understanding the genetic diversity and phylogenetic relationships of the Hemerocallis germplasm is essential for efficient use and improvement of the night lily. In this study, from 155 Hemerocallis accessions, a core collection was constructed based on both SSR markers and the phenotypic data from 32 traits and a stepwise sampling strategy. The 32 accessions in the core collection captured majority of molecular and morphological diversities in the original population. While the molecular data and morphological data provided equal power in assessing the genetic diversity of the core collection, the pollen morphology has its limitation in the study of the genetic relationship within Hemerocallis. Clustering analysis of the core collection classified the 32 accessions into two major groups: night lily and day lily, with the daylily being more ancestral and the night lily having a narrower genetic basis. There is extensive phenotypic diversity for yield and other horticulturally important traits in the Hemerocallis core collection that is useful for night lily improvement.