Abstract: A low-temperature-sensitive seedling-colour mutaut Fan 5 was discovered in the field from breeding family in 1990 in Hangzhou. The experiment carried out under condition of artificially controlled five kinds of temperature (20℃, 23.1℃, 26.1℃, 28℃, 30.1℃ ) showed that the seedling-colour of Fan 5 was white at lower temperature(<20℃ ), yellowish white at 23.1℃, yellowish green at 26.1℃, but was normal (green) at higher temperature (>28℃) and that its critical temperature was about 26.1 ℃ for seedling-colour alteration in ten days after sowing. The results of segregation ratios of green seedling to white seedling from F₁, F₂ and BC₁ populations at 20℃ indicated that a recessive nuclear gene controlled low-temperature-sensitive seedling-colour character in the mutant, which would be used as reasonable morphological indicator character for purifing dual-purpose male-sterile line and its hybrids.

Key words: genetic analysis, low-temperature-sensitivity, seedling-colour

关键词: 遗传分析, 低温敏感, 苗色