Flowering Time Regulation Of The Freesia And The Analysis Of The Change Of The Plants' DNA Methylation

This paper studied the effects on Freesia's flowering period by different size corms, planting time, temperature, different combinations of 5-azacytidine(5-azaC), chilling, gibberellins(GA) and Ethrel. This paper employed the method of MSAP to detect the changes of DNA methylation level of those plants that can promote flowering.The results showed: the bolting and flowering time of the big and middle corm came earlier than the small; planting time doesn't affect the bolting and flowering time; different temperatures affect the bolting and flowering time to some degree, with 12℃chilling treatment for 50 days (12℃(50d)), the bolting and flowering time came 7.7 and 10.3 days earlier respectively; 4℃(50d) didn't affect the time; when the corms were soaked in 45mg/kg gibberllin or 55mg/kg ethrel for 24hr before the 50 days'12℃chilling, the bolting and flowering time with 12℃(50d)+GA(45mg/kg) came 28.5days and 20.1days earlier respectively, with 12℃(50d)+Ethrel(55mg/kg) came 22.3 days and 12.8 days earlier respectively, when the corms were soaked in 45mg/kg gibberllin for 24hr after 55mg/kg ethrel for 24hr before the 50 days'12℃chilling, with 12℃(50d)+GA(45mg/kg)+Ethrel(55mg/kg) came 27.5 days and 16.3 days earlier; when the corms were soaked respectively in 20mg/L,50mg/L and 80mg/L 5-azacytidine for 120 hr before the 50 days'12℃chilling, the bolting and flowering time with12℃(50d)+5-azaC(20mg/L)came 33.5 days and 22.7days earlier respectively, with 12℃(50d)+5-azaC(50mg/L)came 35.5 days and 28.2 days earlier respectively, with 12℃(50d)+ 5-azaC(80mg/L)came 27.7 days and 17.9 days earlier; when the corms were solely soaked in 20mg/L,50mg/L and 80mg/L 5-azacytidine for 120 hr, no effects were found on the bolting and flowering time.The DNA methylation levels on average of those flowering - promoting treatments -12℃(50d)+GA(45mg/kg),12℃(50d)+Ethrel(55mg/kg),12℃(50d)+GA(45mg/kg)+ Ethrel(55mg/kg),12℃(50d)+5-azaC(50mg/L),12℃(50d)-are14.27%,13.33%, 13.98%, 13.33% and 13.20%, all of which are higher than the CK 12.22%.