The aim of this study is to describe the ultrastructural changes of the egg apparatus associated with fertilisation of the natural tetraploid Trifolium pratense. The pollen tube enters one of the synergids through the filliform apparatus from the micropyle. Before the entry of the pollen tube into the embryo sac, one of the synergids begins to degenerate, as indicated by increased electron dens...

Mutant strains of Rhizobium trifolii that induce nitrogenase activity in the free-living state were isolated. These strains, unlike the wild type, nodulated soybean and mungbean plants, producing effective nodules. One of the strains, strain DT72, also nodulated clover but the nodules were ineffective. Strain DT125 consumed hydrogen gas from the gas phase, which can be coupled to nitrogenase ac...