Ecological, micro-morphological and molecular studies on (Medicago L.) species in rangeland ecosystems of Golestan province, Iran

In order to identify the ecological, micro-morphological and molecular characteristics of six alfalfa species (Medicago L.), this research was conducted by collecting data of habitat information, vegetation characteristics and the soil characteristic in sampling depth (0 to 30 cm) of the species in their habitat. The pollen grain morphology of the species was investigated using scanning electron microscopy (SEM). Investigation of the molecular relationships between six species was done using nuclear nrDNA ITS and rpl32-trnL(UAG) chloroplast sequences. The results of the ecological study showed that the most species in the study area grew in arid to semi-arid climate and in silty, silty-clay and silty-clay-loam soils. Based on the results, most of the pollen grains were medium-sized and trizoncolporate and rarely had four to six colpus. In addition, molecular studies showed that all the tested species formed a monophyletic group with high support. The perennial Medicago species was located in a separate clade in the vicinity of the annual species, which indicates that the annual species are monophyletic. The results of this study indicate the efficiency of molecular markers in determining the relationship of taxa at the species level, and it can be used as a complementary tool in the taxonomic identification of Medicago species.