Lathyrus L. is a genus belongs to the legume family Fabaceae and has numerous species. They are native to temperate areas, and widely distributed in Europe, North America, Asia, tropical East Africa, and South America. This genus has several sections, including annual or perennial species. This book discusses the applications of biochemical and molecular markers for assessing the genetic diversity and phylogenetic relationships of Lathyrus L. germplasm in order to provide developed technologies for crop improvement. This book is of interest to plant geneticists, plant breeders, researchers, and scientists.