NODULATION AND GROWTH OF COMMON BEAN (PHASEOLUS-VULGARIS L) CULTIVARSIN HYDROPONIC CULTURE AND IN THE FIELD

Hydroponic culture of four common bean (Phaseolus vulgaris L.) cultiva rs was assessed as a means of selecting cultivars on the basis of thei r capacity to fix N in symbiosis with rhizobium. Two segregants of cul tivar CC 25-9 with different seed colours were included. Bean growth i n hydroponic cultivation was comparable to that in the field but nodul ation was higher in the greenhouse than in the field. A strain-cultiva r interaction on nodulation was significant in cultivar CC 25-9, in wh ich some plant factor, possibly related to seed colour, limited nodula tion since black-seeded beans nodulated significantly less with Rhizob ium leguminosarum by phaseoli CF1 than segregants having red or white seeds. Another strain-cultivar interaction affected nodule function si nce BAT 482 had a significantly lower specific nodule activity than ot her cultivars in symbiosis with strain CF1.