Polymorphism of the storage proteins in Portuguese rye (Secale cereale L.) populations

Currently, due to the abandonment of traditional agricultural practices and the decline of rye production in Portugal, there is a need to assess the genetic diversity of rye in order to preserve its biodiversity. Furthermore, a greater knowledge of rye secalins is important for rye bread-making quality and other crop breeding purposes. The genetic variation and diversity of storage proteins were estimated for fourteen populations of rye (Secale cereale L.) sampled in northern Portugal. The work showed the high genetic diversity within the Portuguese rye gene-pool as an important source for plant breeding and emphasized the necessity of an integrated resources genetic program to allow a more efficient management and conservation of these resources. The rye populations were compared with 'Picasso' and 'Marder' varieties. Several alleles were identified by the single electrophoretic mobility patterns. We studied a set of 1600 rye seeds, including regional populations and varieties, having observed a total of 24, 5, 21 and 47 alleles for HMW, 75k γ-, 40k γ- and ω-secalins, respectively. The coefficient of similarity within populations is presented using cluster representation. The mean value of genetic variation indices (H) for rye storage proteins was very high in regional populations, ranging from 0.67 to 0.78, while in the varieties ranged from 0.57 to 0.58. Knowledge of the diversity of secalins will increase our understanding of the quality differences between rye varieties, especially considering the relative small number of rye cultivars grown around the world.