Genetic diversity of mandarin orange discovered

UN/DICYT A UNal-Palmira and Regional Autonomous Corporation of Caldas (CORPOICA, for its Spanish acronym) study determined that there is an important genetic variability of this species, enabling its maintenance and preservation.

Despite being a very much consumed fruit around the world the precise genome contribution of its ancestral species is unknown. This has turned it into a research target for different research groups around the world which hope to molecularly classify citric fruits.

At UNal-Palmira Mauricio Fernando Martínez a Biology Sciences master’s candidate began to research the genetic diversity of 111 Citrus spp mandarin orange genotypes of the germoplasm bank and work collections of CORPOICA in Palmira, Santander and Villavicencio, through molecular markers known as RAMs and 14 microsatellite markers.

Biological Diversity Research Group Director and project leader Professor Jaime Eduardo Muñoz, says that for all the genotypes they amplified six fruit DNA fragments (RAMs primers) that produced 95 total fractions with molecular weights between 200 and 1,500.

From the samples the researcher produced a DNA collection from the germoplasm bank and the collections from three research centers. This compilation is formed by 99 samples of mandarin orange trees, five from tangelo oranges, four orange, one grapefruit and two acid limes stored at 50° C (122° F) for future research projects.

“We discovered high genetic diversity with microsatellite markers for Citrus spp and Citrus reticulata mandarin orange crops. This indicates that despite that they come from the germoplasm bank and work collections an important generic variability is preserved to maintain the species,” said Muñoz.

This result contributes to knowledge of the genetic variability of cultivated mandarin oranges in Colombia and also serves to determine if there are material duplicates in the studied bank.

According to the Food and Agriculture Organization of the United Nations (FAO), world production of citric fruits surpasses 122 million tons, above bananas, grapes and apples. And among this production, mandarin oranges have an important position as they are almost 20% of this total. Colombia is placed 21st in producing countries with a production of 0,85 million extracted tons.