Effects of Selection on Genetic Parameters of Secale montanum Based on Seed Storage Protein Marker

Secale montanum is one of the important perennial grasses growing naturally in arid to semiarid pastures and rangelands, with a typical Mediterranean climate, in northern and western Iran at altitudes of 800-2900 m. In this paper, seed storage protein profiles of nine wild populations of S. montanum from different regions of Iran and their phenotypically superior progenies as well as a multi-origin polycross (PLC) were studied. High levels of polymorphism were observed over all populations with the average number of bands and average heterozygosity. Superior progeny of different populations showed less genetic variability than wild parents in terms of band diversity, whereas PLC samples showed extremely high values of genetic parameters. Two locally common bands were observed in almost all wild parent populations, which are missing in superior progeny of different populations and PLC. These results provide highly support for the hypothesis that neutral genetic diversity has been reduced or inadvertently lost via artificial selection. Among wild parent populations and their superior progenies significant differences were observed in expected heterozygosity suggesting that more intensive breeding practices may have resulted in a further erosion of genetic variability. Neighbor-joining cluster analysis showed that wild populations and the phenotypically superior progeny of different populations were separated into two groups. This suggests that founder effects and subsequent selection have had more effect on the genetic differentiation between these accessions than geographical separation. This technology, seed storage protein profiling, has great potential for use in breeding programmes.