Guangxi Zhiwu (Feb 2023)

Flower bud differentiation characteristics and endogenous hormone changes of in single and lateral-flowered tree peony (Paeonia Sect. Moutan) cultivars

  • Tingqiao CHEN,
  • Xiaoxiao DONG,
  • Tao YUAN,
  • Qingdao LI,
  • Peiting BIE

DOI
https://doi.org/10.11931/guihaia.gxzw202111068
Journal volume & issue
Vol. 43, no. 2
pp. 368 – 378

Abstract

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The flower bud differentiation process, morphological features and endogenous hormone changes during single-flowered Paeonia suffruticosa cultivar ‘Lihua Fen’ and lateral-flowered cultivars ‘Zimei Youchun’ and ‘Yun’e Fen’ were compared. The flower bud differentiation process of ‘Lihua Fen’, ‘Zimei Youchun’ and ‘Yun’e Fen’ were observed by anatomy and paraffin sections. The contents of auxin (IAA), abscisic acid (ABA), gibberellin (GA3) and zeatin nucleoside (ZR) in ‘Lihua Fen’ and ‘Zimei Youchun’ at different differentiation stages were determined by enzyme-linked immunosorbent assay (ELISA). The results were as follows: (1)The flower bud differentiation of ‘Lihua Fen’ was only 6 stages and that of ‘Zimei Youchun’ and ‘Yun’e Fen’ were 11 stages. The top flower primordium differentiated earlier than the lateral flower primordium. (2) The contents of ABA, GA3 and ZR of ‘Zimei Youchun’ and ‘Lihua Fen’ increased during the leaf primordium differentiating to the bract primordium, while the content of IAA decreased. As for ‘Zimei Youchun’, ABA and GA3 contents decreased at the initial stage of lateral flower primordium, while ZR and IAA increased. (3) The ABA/IAA of ‘Lihua Fen’ was the lowest at morphological differentiation stage. The study reveals that the lateral-flowered cultivars have earlier and longer flower bud differentiation compared with the single-flowered cultivar, parts of the floral organ differentiation stage of apical and lateral flowers overlaps. Higher ZR and IAA levels and lower ABA and GA3 levels are beneficial to initiate lateral flower primordium differentiation. The results provide a reference for the long florescence breeding of tree peony.

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