Study On Shade-tolerance Of Four Cultivars Of Miscanthus Sinensis

There were four shading levels, 0%, 25%, 50% and 75%, respectively, by using black shade cloth and researched the effects of shading on the growth, physiological indices, ornamental characteristics of four cultivars of Miscanthus sinensis, M.sinensis'Gracillimus', M.sinensis'Strictus', M.sinensis'variegates', M.sinensis'Morning light'. We sort their tolerant abilities and filter out indicators that could be used to evaluate the shade-tolerance abilities, to use it in landscaping and provide the basis.The main conclusions of the study are as follows:1. Under shading conditions, leaf length, leaf width, plant size and internode of the four varieties of Miscanthus sinensis first increased and then decreased.With the increase in the shading, the leaf length of M.sinensis'Strictus'and M.sinensis'Gracillimus'increased, the leaf length of M.sinensis'variegates'and M.sinensis'Morning light'is increased with the degree of shade, first by large and then decreased; the leaf width of M.sinensis'Strictus'were not significant different, the leaf width of M.sinensis'variegates'and M.sinensis'Gracillimus'increased with the degree of shade, then decreased and then increased.With the increase in the shading, specific leaf dry weight and tiller number decreased.2. With the increase in the shading, four cultivars of Miscanthus sinensis grown faster under shading than CK. Then M.sinensis'Strictus'and M.sinensis'Gracillimus'grown fast in 50% shading, M.sinensis'variegatus'and M.sinensis'Morning light'grown fast in 25%.3. With the increase in the shading, the biggest leaf water content of four cultivars of Miscanthus was in 75% shading degree.The shoot dry weight of M.sinensis'Strictus', M.sinensis'variegates'and M.sinensis'Gracillimus'first increased then decreased, while M.sinensis'Morning light'decreased.The stem dry weight of M.sinensis'Strictus'and M.sinensis'variegates'first increased then decreased, M.sinensis'Gracillimus'and M.sinensis'Morning light'decreased. The leaf dry weight of M.sinensis'Strictus', M.sinensis'Gracillimus'and M.sinensis'Morning light'first increased then decreased, M.sinensis'variegates'decreased.4. With the increase in the shading, the rule of total chlorophyll and chlorophy a of four cultivars of Miscanthus sinensis was same, Miscanthus sinensis'Strictus'and M.sinensis'Morning light'increased,but decreased in 75% shading. M.sinensis'variegates'and M.sinensis'Gracillimus'increased.The four cultivars of Miscanthus sinensis with the increase in the shade , the net photosynthetic rate and praline decreased, the membrane permeability increased.5. With the increase in the shading, the flowering rate of M.sinensis'Strictus'and M.sinensis'variegates'decreased, the flowering rate of M.sinensis'Gracillimus'increased and then decreased; the number of inflorescence of 3 cultivars of Miscanthus sinensis, M.sinensis'Strictus', M.sinensis'variegates'and M.sinensis'Gracillimus'first increased and then decreased.The inflorescence length of M.sinensis'Strictus'and M.sinensis'Gracillimus'decreased, but M.sinensis'variegates'increased. Shading reduced the flowering rate of Miscanthus sinensis and pulled off wither stage, first flowering stage.6. The result indicates that the shade tolerance is:M.sinensis'Gracillimus'>M.sinensis'Strictus'>M.sinensis'variegates'>M.sinensis'Morning light'.M.sinensis'variegates', M.sinensis'Morning light'can be planted under 50% shading, while M.sinensis'Gracillimus', M.sinensis'Strictus'can be planted under 50% shading.7. The results identifies larger relevant indicators of shade tolerance for four cultivars of Miscanthus sinensis. Plant height, Leaf length, Leaf water content, Specific leaf dry weight, Shoot dry weight, Membrane permeability.