Research on Open-pollination Progeny Test in Loblolly Pine(Pinus taeda)

An investigation was made on the seedling and juvenile stage of 47 open-pollination families in Pinus taeda L..The results show that the variance of preservation percentand height of seedling between the families are significant.The perservation percent is correlated with seedling height, but the seedling height growth is not correlated with saplingheight growth.The differences of height growth between families are significant.There isover 1/5 of the 47 families superior in height growth.In addition,the influence of statisticanalysis method and selection critirion on selection effect were studied,effectiveness of elimination of inferior seedlings was also investigated.