|Authors: ||A. Gentile, S. La Malfa|
|Keywords: ||cactus pear, genetic improvement, germplasm collection, molecular markers|
According to the different classification methods, the genus Opuntia belongs to the Cactaceae family native to the Americas and encompasses several species ranging from 75 to 250. The most economically important species is O. ficus-indica (Mill.) known as cactus pear, but the genus includes other important edible species, which are spread, wild, or cultivated in many regions worldwide. Opuntia species are gaining popularity in different areas, arid and semi-arid, both for fruit production for human consumption, and mainly for animal feeding using the tender and mature green part of the whole plant (cladodes). The main goals for breeding programs in Opuntia are related to the development of spineless cultivars with high level of productivity, high fruit quality, pest and disease tolerance.
As for forage varieties, cold tolerance, spineless pads and high biomass productivity are the actual goals in developing new genotypes.
Attention is also paid to nutrient content and palatability.
Breeding of Opuntia is hampered by several factors: the lack of reliable morphological descriptors, the recurrent intra- and intergeneric hybridization, the frequent polyploidy, and the phenotypic variation displayed by the genotypes under different ecological conditions.
In the last years, several DNA-based studies, relying on different categories of molecular markers, have been carried out in order to better assess variability level within the main cultivated species (O. ficus-indica), to establish relationships among the main close relative species and varieties and finally to help breeders.
So far, the use of biotechnological tools has been poorly considered for cactus pear improvement.
However, the adoption of accurate large-scale phenotyping of existing germplasm collections could lead to functional management of genetic resources for their sustainable conservation and plan future breeding strategies for improved genotypes to be cultivated in distinct areas for different purposes.
In the present contribution challenges and strategies of cactus pear breeding and management of genetic resources will be described, with a special emphasis on the role of molecular breeding.
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