Early Selection of Fast-growing and Highly Resistant Clones of Casuarina equisetifolia in Coastal Areas under the Influence of Typhoons

In order to explore the genetic variation patterns of growth and resistance traits of Casuarina equisetifolia,forty-eight clones in Chihu State-owned Protective Forest Farm were used as candidates to undertake fast-growing and highly resistant clones selection based on observation data of growth, wind and insect resistances traits after undergoing “Morandi” typhoon attack in 2010.According to the results, the average values of diameter at breast height（DBH）,tree height, individual volume, wind resistance, survival rate（SR）,pest infestation rate of the 48 clones were 5.75 cm, 6.39 m, and 0.0063 m³,3.31,80.36% and 14.29%,respectively, and coefficient of variation of these traits were 25.85%,14.50%,60.94%,29.63%,17.19% and 79.80%,respectively.The genetic differences of tree height, DBH,individual volume, wind resistance and pest infestation rate among these clones reached a very significant level, but survival rate was not significant.The repeatability of DBH,tree height, individual volume, wind resistance, survival rate and pest infestation rate were 0.50,0.52,0.46,0.47,0.08,0.41,respectively, indicated that the 6 traits were under moderate genetic control, and concrete genetic gains can be obtained through clone selection.Based on the inclusion criteria of 20%,10 superior clones of C.equisetifolia,including Hui 2,Yue 701-3 and Long 4,etc.were considered the fast-growing and highly resistant clones in terms of Bregin multi-trait comprehensive evaluation method.