Early family selection in jack pine

Abstract

Twenty open-pollinated families of jack pine (Pinusbanksiana Lamb.) were grown for 16 to 21 months in two different greenhouse regimes, one providing an extended growing season with natural photoperiod and one employing control of temperature and photoperiod to accelerate growth cycles. Height measurements during and at the end of greenhouse growth were compared with height of 7-year-old seedlings of the same families growing in field tests. For both greenhouse regimes, height at the end of the second growth cycle was positively correlated with 7-year field height. Greenhouse measurements correctly classified the majority of families into upper and lower groups based on field heights. Early family selection in jack pine appears to have applications in long-term breeding strategies.