Effects of Sub-low Temperature and Drought Stress on Growth and Leaf Anatomic Structure of Lily

In order to understand the resistance of lily to sub-low temperature and drought stress, the growth characteristics and leaf anatomical structures were studied under sub-low temperature and drought conditions by using lily 'Yellow Beauty' (Lilium hybrida) as materials. The results showed that the growth rates of plant height under drought group and sub-low temperature group were not significantly different than control group, while it was significantly lower under the interaction of sub-low temperature and drought stress as that of the control group. The root to shoot ratio significantly increased under sub-low temperature and drought stress, while it reached a peak under the interaction of sub-low temperature and drought stress. Compare 2 single treatment groups, it showed that the influence of sub-low temperature on growth is more than that of drought. The leaf thickness under sub-low temperature and drought stress was significantly higher than that of control group. However, the leaf thickness, palisade tissue thickness and spongy tissue thickness under the interaction of sub-low temperature and drought stress decreased compared with the control value. Spongy tissue thickness was positively correlated with leaf thickness under drought stress. Palisade tissue thickness and sponge tissue thickness was positively and negatively correlated with the ratio of palisade tissue thickness / spongy tissue thickness under sub-low temperature. The comprehensive scores of the treatments were ranked as drought treatment group > control group > low temperature treatment group > sub-low temperature and drought group. The results indicated that the lily could alleviate it damage by increasing the biomass distribution of root and the leaf thickness. The damage of sub-low temperature and the interaction of sub-low temperature and drought stress were more severe to the species, thus significantly inhibiting the growth of lily.