Table 1.

RFLP patterns observed among cloned nifHPCR fragments

RFLP patternaNo. (%) of clonesnifH clone(s) sequencedb
LitterTopsoilDeeper soil
Ia7 (17)2 (4)A1, B55
Ib4 (9)B18
Ic3 (6)B30
Id1 (6)C5
Ie1 (2)A25
If1 (2)B21
II10 (24)A2
III3 (7)A5
IV8 (19)A7
V5 (12)A10
VI6 (15)A37
VII1 (2)A39
VIII1 (2)6 (13)A47, B10
IX8 (17)15 (88)B12, C1
X7 (15)1 (6)B1, C20
XI6 (13)B3
XII7 (15)B9
XIII1 (2)B13
XIV1 (2)B25
XV1 (2)B34
Total42 (100)47 (100)17 (100)
  • a RFLP patterns were designated as explained in the text.

  • b The nifH clones were designated on the basis of their sources, as follows: A, litter; B, topsoil; and C, deeper soil.