MORPHOGENESIS OF ROOT-NODULES IN WHITE CLOVER - I - EFFECTIVE ROOT-NODULES INDUCED BY THE WILD-TYPE RHIZOBIUM-LEGUMINOSARUM BIOVAR. TRIFOLII

The research aimed at investigating the morphogenesis of cylindrical r oot nodules in Trifolium repens L. induced by the wild type Rhizobium leguminosarum biovar. trifolii strain 24. It has been demonstrated tha t the ontogenesis of a nodule begins with a transverse division of cel ls of the pericycle followed by the dedifferentiation and divisions of cells of the endodermis and inner layers of the primary root cortex. Shifting of the nodule meristem from its initially lateral to the apic al position characteristic for cylindrical nodules was observed. Bacte riocidal, conical and vascular tissues of the nodule are described up to 42 days after inoculation. At that time typical degraded zone had n ot yet appeared in the nodules.