Tulasnella calospora (UAMH 9824) retains its effectiveness at facilitating orchid symbiotic germination in vitro after two decades of subculturing

Botanical Studies

Table 2 A comparison of in vitro symbiotic vs. asymbiotic seed germination of Spiranthes cernua by growth stage 42 days after sowing

Treatment	n^a	# Seeds	Stage 0	Stage 1	Stage 2	Stage 3	Stage 4	Stage 5^b	% Germination (± SE)^c
P723	10	730	700	25	5	0	0	0	3.68 (1.16)^a
B141	9	634	584	39	11	0	0	0	8.94 (2.47)^b
OMA + 266	10	690	466	113	10	29	32	40 (5.8)	33.73 (2.73)^c
OMA + P44	10	735	481	89	51	55	50	9 (1.2)	34.65 (1.84)^c
OMA + EE465	10	745	672	65	8	0	0	0	9.65 (0.91)^b
OMA + 427	10	848	598	242	8	0	0	0	29.56 (1.68)^c
OMA control	10	665	663	2	0	0	0	0	0.31 (0.31)^a

Note that Tulasnella calospora 266 facilitated the largest percentage of seedlings (> 5.8%) to the highest growth stage for all treatments including the three symbiotic treatments that utilized fungi isolated more recently (2016 and 2018)
^aNumber of replicate petri plates (n) for a given treatment. Unequal sample sizes resulted when contaminated plates were discarded
^bValues in parentheses reflect the percentage of seeds in a given treatment that developed to Stage 5
^cMeans denoted by the same letter were not significantly different (α = 0.05)