EN
The pollen grain germination and the growth of pollen tubes after intra- and interspecific reciprocal pollination of Lupinus albus L., L. mutabilis Sweet, and L. angustifolius L. were examined. Results of microscopic observations of pollen grain germination and pollen tube growth enable to deny the existence of certain barriers that prevent fertilization after pollination of L. albus flowers with pollen of L. angustifolius and vice versa, as well as after pollination of L. mutabilis flowers with pollen of L. angustifolius and vice versa. Some delay in pollen grain germination and a slower growth of pollen tubes were observed in all combinations, as related to intraspecific ones, though in the case of each interspecific combination pollen tubes reached the ovary. Moreover, a different level of pollination efficiency (the number of growing pollen tubes) and various rates of pollen grain germination and pollen tube growth, depending on the direction of pollination, were found. The noted pollination efficiency may generally be considered to be low.