Table 1.

Seed and root exudate compounds with known nod gene-activating factors, from legumes with broad or narrow ranges of symbiotic compatibility.

Species	Source	nod gene- activating factors	Source
Glycine max	Root exudates	Daidzein, genistein, coumestrol, isoliquiritigenin	Kape et al. (1992), Pueppke et al. (1998)
G. max	Seeds	Daidzein, genistein	Pueppke et al. (1998)
Medicago sativa	Seeds	Chryoseriol, luteolin, liquiritigenin	Maxwell et al. (1989), Hartwig et al. (1990)
M. sativa	Root exudates	4,7-dihydroxyflavone formononetinin	Maxwell et al. (1989)
Phaseolus vulgaris	Root exudates	Genistein, eriodictyol, naringenin, daidzein, coumesterol	Davis and Johnston (1990), Hungria et al. (1991b), Dakora et al. (1993b)
P. vulgaris	Seeds	Unidentified isoflavone, delphinidin, petunidin, malvidin, myricetin, quercetin, kaempferol	Hungria et al., 1991a
Vigna unguiculata	Root exudates	Daidzein, genistein, and glycitein	Dakora (2000)