Morphological characterization of cactus pear (Opuntia ficus-indica) accessions from Agadir, Morocco

Abstract

Proceeding paper on Morphological characterization of cactus pear (Opuntia ficus-indica) accessions from Agadir, Morocco: The North Africa region falls under an arid or semi-arid climate and is considered as a hot spot for climate change. To combat feed shortages, increase the income of the rural poor and mitigate the effect of climate change, around 1 million ha of cactus crop has been planted in Tunisia, Algeria, and Morocco. Aware of the importance of germplasm, ex-situ collections are being initiated in the region, where promising accessions have been introduced from many countries. The objective of this contribution was to assess the genetic diversity of 20 cactus pear accessions from the ex-situ collection located at the INRA Morocco research station in Agadir using morphological characterization based on FAO Cactusnet descriptors. The data were subjected to principal component analysis (PCA) and agglomerative hierarchical clustering (AHC) using the XLSTAT 2015 package. The results showed that the accessions can be discriminated by some of the morphological descriptors. Many of these morphological descriptors were significantly correlated, such as number of cladodes and number of fruits (r=0.73), number of cladodes and plant diameter (r=0.73), length of the cladode and plant height (r=0.7), and length of spines and number of areoles (r=0.67). Cladode shape and the number of spines and areoles are the recommended descriptors, since they were capable of discriminating accessions with suitable accuracy. Other descriptors do not seem to influence the morphological characterization, including cladode thickness, number of spines, plant height, and cladode shape index. Therefore, PCA and AHC are efficient tools for segregating accessions using a reduced number of morphological descriptors. Another important finding is that the number of morphological descriptors may be reduced without potential risk of reducing the accuracy of the phenotypic characterization for this particular collection and location.