Euphorbiaceae is a particularly interesting family for the study of sexual differentiation as it is characterized by having unisexual flowers in monoecious or dioecious plants and displays great diversity in structure of flowers and inflorescences. Plukenetia volubilis , is a monoecious species with numerous male flowers, but single female flower in a thyrse.(Euphorbiaceae), commonly known as sacha inchi 

However, no study has compared the very early stages of male and female P. volubilis flower development to ascertain when and how the first morphological differences between the sexes appear. 

Researchers from Xishuangbanna Tropical Botanical Garden (XTBG) undertook a floral organogenesis study of P. volubilis to characterize the development of the two sexual flowers, document the differences between them, and to uncover the time of sex determination. 

They applied exogenous 6-benzyladenine (BA), which is a synthesized plant growth regulator functioning as cytokinin, to modify flower sex in this species to reveal the effects of cytokinin on sex determination at the flower developmental level. 

The results revealed that sex determination occurs at early developmental stage, and exogenous cytokine in treatment can take effect on the meristem of male flowers to lead it to feminizing. 

“Our study shed light on the developmental mechanism of sex determination in P. volubilis and provided a better understanding of the factors that control primordium initiation within the male and female flowers”, said Prof. XU Zengfu, principal investigator of the study. 

The study entitled “Developmental basis for flower sex determination and effects of cytokinin on sex determination in Plukenetia volubilis (Euphorbiaceae)” has been published in Plant Reproduction. 

Contact 

XU Zengfu Ph.D Principal Investigator  

Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun 666303, Yunnan, China