title: Metaxenia in the vine cacti Hylocereus polyrhizus and Selenicereus spp.
abstract: OBJECTIVE
  Flowers of the vine cacti of the genera Hylocereus and Selenicereus grown in Israel must be hand pollinated due to self-incompatibility and lack of efficient pollinators. In controlled pollination experiments, it was found that the time elapsed between pollination and ripening depends on the source of the pollen. Therefore a study was made of some effects of the pollen source on fruit development.
  
  
  METHODS
  Flowers of Hylocereus polyrhizus were pollinated on the same day with different pollen sources and the stigmas were covered. Fruits were collected 4 d after reaching full colour.
  
  
  RESULTS
  Pollinating flowers of Hylocereus polyrhizus with Selenicereus grandiflorus and S. megalanthus pollen delayed ripening by 1 and 3 weeks, respectively, as compared with ripening of fruits pollinated with Hylocereus undatus pollen. Other fruit characteristics affected by the pollen source were fruit size, pulp dry weight and number of seeds per fruit, all being significantly reduced, while peel dry weight was significantly increased by S. megalanthus pollen. Total soluble sugar content was reduced in H. polyrhizus fruits pollinated with S. grandiflorus pollen. No other major traits were affected.
  
  
  CONCLUSIONS
  The results are evidence for the existence of metaxenia, i.e. an effect of pollen on maternal tissues, in cacti fruits. This pollen effect on the fruit-ripening time may be used for extending the marketing period of H. polyrhizus fruits.
authors.affiliation: Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel. mizrahi@bgumail.bgu.ac.il
authors.forename: Yosef
authors.initials: Y
authors.lastname: Mizrahi
authors.forename: Joseph
authors.initials: J
authors.lastname: Mouyal
authors.forename: Avinoam
authors.initials: A
authors.lastname: Nerd
authors.forename: Yaron
authors.initials: Y
authors.lastname: Sitrit
mesh_terms: D029421:Cactaceae / Q000502:physiology*; D005306:Fertilization / Q000502:physiology; D035264:Flowers / Q000502:physiology*; D005638:Fruit / Q000254:growth & development*; D011058:Pollen / Q000502:physiology*; D012639:Seeds / Q000254:growth & development; D013997:Time Factors