A group of scientists from Palmira discovered a regeneration technique based on organogenesis, which constitutes the first step in order to genetically transform the pitahaya via biotechnological strategies.
The Cactaceae are a family of plants with around 1,600 species, distributed, in native form, from Argentina to Canada. According to scientists from the National University of Colombia in Palmira, their species are characterized by the efficient use of water (five to ten times more than conventional crops), in relation to the CAM (crassulacean acid metabolism) photosynthetic pathway.
Many species, of which 35 have high potential for being cultivated, are known as pitahaya, pitaya, pitajaya, dragon fruit and calyx flower, among others. The pitahaya is consumed fresh or processed and its high content of soluble solids makes it highly viable for the market and agribusiness sector.
The best know specie in Colombia is the Selenicereus megalanthus, also known as yellow pitahaya because of the colour of its outer skin. It is a species that, according to Professor Creuci Maria Caetano, naturally propagates via cuttings (cladodes) and the seeds spread by birds and other animals.
"The sexual propagation of the plants is not recommended for cultivation purposes because the plants require much care and take four to six years to reach their reproductive stage," said Caetano.
This specie can be propagated via tissue culture, a technique that isolates a portion of the plant (explant) and artificially provides it with the physical and chemical conditions so that the cells express their induced potential.
"The development of tissue culture for different cactaceae has been described by many scientists. However, there are scarce studies for the Colombian specie; hence, we started research to develop a protocol for clonal propagation and regeneration of yellow pitahaya, in order to implement a production system of seedlings and an assisted breeding program," said the professor.
The researchers collected a genotype of the yellow pitahaya that had outstanding morphoagronomic features such as fruit weight, pulp to shell ratio, soluble solids (oBrix), carbohydrates, ether extract, energy and pH, among others.
" The explants used to correspond to disinfected adult plants with meristematic tissue (lateral areoles) obtained from in vitro plantlets, originated from petri dish sprouts. Vegetative and reproductive structures were formed from those areoles," Diego Geraldo Caetano Nuñez, a PhD student in Agricultural Sciences.
The results allowed researchers to conclude that the observed regeneration path and indirect organogenesis is the first step to establish trials for the genetic transformation of pitahaya via biotechnological strategies.
"We've standardized this protocol for the first time. The tested explant (areola), present in much of the plant's vegetative structure, responded effectively to stimuli," said Caetano.
In short, researchers proved the protocol's safety for the regeneration of yellow pitahaya.
The full protocol is published in the latest edition of the Acata Agricultural Magazine.
Source: Agencia de Noticias UN