Abstract:

Photoperiod-sensitive Female Sterile Ramie (PFSR) is sterile with long-day photoperiods (LD, ≥13 h 30 min light/d ) and fertile with short-day photoperiods (SD, ≤13 h 20 min light/d ). The treatment in the study were composed of LD, SD, and long dark phase (14 h dark/d) in SD photoperiods (10 h light/d) of PFSR with red light (R) / far red light (FR) alternate illuminations which is the standard reverse examination to check if phytochrome is the photoreceptor in a photo-induced reaction. The results showed that female sterile was induced and flower budding and flowering were deferred by R-breaking while these effects were reversed by FR-breaking and female became fertile. Female fertility was induced in the treatments with FR, R+FR and SD (10 h light/d ), and female sterility was induced in the treatments with R, FR+R, R+FR+R and LD (>14 h light/d ), but these were no effects on male fertility in all the treatments. It was indicated that phytochrome is the photoreceptor of female photoperiod-sensitive sterility in PFSR.

Key words: Phytochrome, Ramie [Boehmeria nivea (L.) Gaud.], Photoperiod-sensitive Female Sterility, Dark-breaking