Annual growth cycle observation, hybridization and forcing culture for improving the ornamental application of Paeonia lactiflora Pall. in the low-latitude regions

Abstract

Expanding the southern range of herbaceous peony ( Paeonia lactiflora Pall.) is a meaningful and worthwhile horticultural endeavor in the Northern Hemisphere. However, high temperatures in winter seriously hinder the bud dormancy release and flowering of peony in the more southern areas of subtropical and tropical regions. Resource introduction and hybridization can contribute to creating new cultivars with high adaptability in a warmer winter climate. In this study, three representative cultivars of P . lactiflora were screened for flowering capabilities and their annual growth cycles were observed to provide information needed for hybridization. Among these three cultivars, ‘Hang Baishao’ is the best adapted cultivar for southern growing regions and is unique in its ability to thrive in southern areas of N 30°00’. Pollen viability of ‘Hang Baishao’ was 55.60% based on five measuring methods, which makes it an excellent male parent in hybridization. Hybrid plants among these three cultivars grew well, but all of their flower buds aborted. Additionally, the ability of three growth regulators that advance the flowering of ‘Hang Baishao’ to promote an indoor cultivation strategy for improving peony application as a potted or cut-flower plant was tested. 5-azacytidine could impact the growth of ‘Hang Baishao’ and induce dwarfism and small flowers but not advance the flowering time. Gibberellin A 3 promoted the sprouting and growth significantly, but all plants eventually withered. Chilling at 0–4°C for four weeks and irrigation with 300 mg/L humic acid was the optimal combination used to hasten flowering and ensure flowering quality simultaneously. These results can lay the foundation for future studies on the chilling requirement trait, bud dormancy release and key functional gene exploration of herbaceous peony. Additionally, this study can also provide guidance for expanding the range of economically important plants with the winter dormancy trait to the low-latitude regions.

Establishment of a Homologous Silencing System with Intact-Plant Infiltration and Minimized Operation for Studying Gene Function in Herbaceous Peonies

“…is the most famous species of herbaceous peony due to its beautiful flowers, elegant leaves, and remarkable pharmaceutical roots. Therefore, this species is specially addressed as the singular "herbaceous peony" and is most widely cultivated in Europe, North America, Australia, and Asia [10]. P. lactiflora has often been selected as a representative species in scientific research on herbaceous peonies [11].…”

DUS evaluation of nine intersubgeneric hybrids of Paeonia lactiflora and fingerprint analysis of the chemical components in the roots

“…The morphological characterization of P. lactiflora. is related to such factors as the environment (Sun et al, 2022), their development and distant hybridization (Zhang et al, 2019). The morphology is not only manifested in flower type, flower color (Tang et al, 2018;Tang et al, 2020;Luo et al, 2021) and plant morphology, but also in the differences in the chemical components (Wang et al, 2014) and the related gene expression (Zhao et al, 2014;Gao et al, 2016).…”

Analysis and Functional Verification of PlPM19L Gene Associated with Drought-Resistance in Paeonia lactiflora Pall.

“…While the northern region of China is mostly arid or semi-arid, the climate is generally dry because there is slight precipitation in spring, and the summer is hot and rainless. In addition, during the growing period, the soil herbaceous peonies are planted in should be kept moist, and in particular, it must not be arid before the flowering period, or the plants can easily wihter [ 7 ]. Obviously, the herbaceous peony has a certain ability to withstand drought, but long-term drought and severe shortages of water will threaten its normal growth and development [ 8 ].…”