Table 1.

Average AM fungal richness for each plant variety at first (47 days) and second sampling (104 days)^a

DNA or RNA	Variety	Pyrosequencing			Reads	104 days			Reads	T-RFLP		104 days
		47 days								47 days
		Mean	SE	n		Mean	SE	n		Mean	SE	n	Mean	SE	n
DNA	M	2.7	0.9	3	9	6.0	0.0	2	137	6.2	0.2	3	6.5	0.5	3
	M-GM	3.5	0.5	2	35	5.3	0.4	3	67	4.2	1.0	3	5.5	0.6	3
	K	2.0	2.0	2	3	6.5	0.5	2	37	4.3	1.3	3	6.3	1.5	3
	K-GM	2.3	0.9	3	8	5.3	0.3	3	146	5.0	1.0	3	5.2	0.8	3
RNA	M	5.0	1.0	3	459	5.8	0.0	2	1159	4.0	1.0	3	6.0	1.2	3
	M-GM	3.8	0.4	2	1109	5.9	0.0	3	718	4.5	0.8	3	6.3	0.4	3
	K	4.6	1.4	2	190	5.2	0.4	2	815	5.3	0.7	3	5.3	1.4	3
	K-GM	4.7	0.7	3	651	5.7	1.0	3	792	5.0	0.5	3	5.5	0.8	3

^aAssessments by pyrosequencing and by T-RFLP (average of forward and reverse T-RF) are presented separately, assessed by DNA and RNA analysis. Different plant varieties are abbreviated by letters: M, Monumental; K, DKC. GM varieties are indicated with an additional identifier (i.e., M-GM and K-GM). For pyrosequencing, to account for differences in total AM fungal read numbers when more than 100 reads were present, AM fungal richness of samples was estimated by a rarefaction analysis estimate of 100 individual sequences (e.g., reference 1). SE, standard error of the mean; n, number of observations; Reads, the mean number of AM fungal reads obtained. In none of the instances was there a significant effect of the GM trait (GM versus non-GM), the cultivar (M versus K), or their interaction on AM fungal richness. For values in italics (pyrosequencing of DNA at both times and RNA at 47 days), not all replicates were represented by at least 100 AM fungal reads and thus no statistics are performed on richness estimates comparing GM with non-GM plants.