Table 4.

Demethylation by mutation at the DDM1 locus promotes flowering of plants grown in short days, but delays flowering when plants are grown in long days

Plant line	Flowering time (SD)
	Unvern	Vern	% Col vern response in ddm1 mutant	Unvern	Vern
Col (expt 1)	40.8 ± 1.5*	35.7 ± 1.8		14.5 ± 0.3†	13.0 ± 0.2
ddm1 (expt 1)§	37.2 ± 0.8*	34.3 ± 0.9	70.4	16.4 ± 0.3†	15.0 ± 0.4
Col (expt 2)	70.0 ± 3.4	40.7 ± 3.0		ND	ND
ddm1 (expt 2)§	48.9 ± 2.3	37.6 ± 2.8	72	ND	ND
Col (expt 3)	72‡	50‡		19.1 ± 0.4	18.2 ± 0.3
ddm1 (expt 3)§	44‡	32‡	>100%	32.1 ± 1.0	33.9 ± 1.1

Flowering time is in days ± SE. SD, short days. LD, long days. ND, not done. 

^*Mann–Whitney U test of ranks gave a standard normal deviate Z = 1.69 (probability of Z ≥ |1.69| is 0.091, not statistically significant). 

^†Mann–Whitney U test of ranks gave a standard normal deviate Z = 4.65 (probability of Z ≥ |4.65| is <0.001). 

^‡Days for 50% of plants to flower (some plants had not flowered before day 85 when the experiment was terminated because the growth medium had dehydrated). 

^§Plants used in expt 1 and expt 2 were from independent Col and ddm1 lines; the latter had been selfed fewer than four times. In expt 3 ddm1 plants were seventh generation self-progeny, from a line identified as late flowering.