Compare on the Needle Phenotypic Variations between the Different Type of Trunk Populations of Pinus yunnanensis

The needles were collected from the different forest stand in Yiliang, Xinping and Lufeng. The plant trees were divided into the straight population and twisted or crooked population based on the morphological characteristics of trunk in canopy and regeneration layer of each forest stand. Seven needle morphological traits were measured for each population. The results showed that there was no difference for seven needle morphological traits between straight population and twisted or crooked population in canopy and regeneration layer. The average values of the needle traits (needle length, needle width, fascicle width, fascicle sheath length) for trees in canopy layer were greater than that for regeneration layer in both straight population and twisted or crooked population. But the needle shape index traits (needle length/needle width, needle length/fascicle sheath length, fascicle width/needle width) had little difference between canopy and regeneration layer in both straight population and twisted or crooked population. There were significant differences for each needle morphological trait both among populations and within population. The order of the coefficient variation of seven traits was: NL/FSL (2220%)> NL/NW (1915%)> FSL (1904%)> NW (1900%)> NL (1661%)> FW (1510%)> FW/NW (1320%). Most needle morphological traits showed the variations among populations was smaller than within population, the mean phenotypic differentiation coefficient had 2090% among populations and 7910% within population, which stated that the variation within group was the main source.