Abstract:
Objective To investigate the effect of resin content of pine cone scales on serotiny.
Method Cone persistent ages, the degree of serotiny and the resin content of current-year cone scales in six pine species (Pinus yunnanensis Franch., P. yunnanensis var. pygmaea Hsueh., P. yunnanensis var. tenuifolia Cheng et Law., P. densata Mast., P. massoniana Lamb., and P. kesiya var. langbianensis Gaussen.) were investigated, and the correlation between resin content of cone scales and the degree of serotiny were analyzed.
Result For the species whose resin content of cone scales less than 6%, the persistence of cones, which is the indication of serotiny, was not observed. In P. yunnanensis varieties characterized by serotiny, the resin content of cone scales was positively related to the degree of serotiny (R2=0.997, P=0.036). However, the relationship between the cone scale resin content and the degree of serotiny was not significant (R2=0.01, P=0.902) across these taxa, which may be due to the large genetic and environmental differences.
Conclusion The results indicate that the resin content of cone scales plays an important role in pine serotiny and there will be no serotiny when it is too low. In P. yunnanensis varieties with serotiny, the serotiny degree is effected by the resin content of cone scales.