Genetic analysis of a garlic (Allium sativum L.) germplasm collection from Argentina

Abstract

Although garlic spreads asexually, it shows a wide diversity for physiologic, morphologic and agronomic characters, due to the accumulation of mutations. Our objective was to examine the genetic diversity of a collection of 43 national and foreign introductions using fluorescent Amplified Fragment Length Polymorphism (fAFLP) markers for characterizing previously phenotypical. 351 bands were obtained, of those 251 were polymorphic. The obtained genotypes were analyzed by means of the program Structure v2.2 according to a mixture model of frequencies correlated by allelic population. Twenty simulations of 55,000 steps defaulting from two to eight different genetic populations were carried out. The solutions with more likelihood were obtained by conforming five groups of clones. Most of the individuals showed compound genotypes for portions of two or more populations and duplications were identified. If the phenotypical classifications are correct, the phenotype can respond to different genetic origins, including individuals genetically atypical in a uniformly phenotypical population. Some clones were isolated after multiple selections on populations of garlic, what is not surprising, is that some are more genetically related than others. The genetic relationships found in the collection of garlic belong together with the classification of the ecophysiological groups, although not in a definitive way, additional analysis being necessary. The conservation of the genetic diversity is of vital importance because it guarantees a broader background with which to practice artificial selection assuring the success of future programs of improvement.