Frankia fixes atmospheric nitrogen:

1.	in the roots of non-leguminous plants like Alnus but unlike Rhizobium does not form any root nodules
2.	in the roots of leguminous plants like Soybean but unlike Rhizobium does not form any root nodules
3.	in the roots of non-leguminous plants like Alnus and like Rhizobium forms root nodules
4.	in the roots of leguminous plants like Soybean and like Rhizobium forms root nodules

Identify the incorrect statement regarding the development of root nodules in soyabean:
1.  Rhizobium bacteria contact a susceptible root hair, divide near it
2. Successful infection of the root hair causes it to curl
3.  Infected thread carries the bacteria to the inner cortex, the bacteria get modified into rod-shaped bacteroids and cause inner cortical and pericycle cells to divide which leads to nodule formation
4.  A mature nodule is complete without any vascular tissues continuous with those of the root.