The Clonal Variation of Female and Male Strobilus Production and Evaluation of Stability for Pinus tabulaeformis Carr.

The successive observations on the female and male strobilus production in Pinus tabulaeformis Carr.seed orchard,located in Lushi County,Henan Province,were carried out during 1985～1995. There was a fluctuation in female and male strobilus production with about a 4 year cycle,and the fluctuations of cone with filled seeds among the years coincided with the male strobilus production,the variations of the cones with filled and emptied seeds did not tend to be stable until abundant cone production.There were significant differences for strobilus production between clones,clonal repeatability of female and male strobilus production over the years were all over 65.12% and 86.49% respectively,greater differences for strobilus production in a seed year than alean year,and in abundant cone period than initial period,and smaller differences between rametswithin clone.The interactive effects of different clone and year for female and male strobilus production were significant,and variance components of interactive effects for female and male strobilus production were 12.03 % and 37.94% respectively.20 clones of stable production for female strobilus and 22 for male were selected from 31 clones.