马尾松球果和种子的生长发育及养分动态

Growth and Nutrition Developmemt of Seed and Cone of Masson Pine

１９９０～１９９３年连续４ａ，对马尾松球果和种子的生长发育与养分动态，进行了比较系统的分析研究。结果表明：（１）马尾松球果系２年成熟，授粉（４月上旬）后当年为幼球果形成期；第２年受精前的６月至以后的９月中旬为球果迅速生长期，９月下旬至１０月为球果成熟期。（２）在２年生球果生长期间，球果干物质不断增加，而水分含量逐渐减少，１０月底干物质与水分的含量达到平衡点。（３）球果养分的含量，ｌ年生球果幼期Ｎ＞Ｋ＞Ｐ，三者变化趋势近乎一致，２年生球果含Ｎ量明显下降。种子内的Ｎ、Ｋ含量在７月中两者相当，此后Ｎ含量上升直至成熟期，到１０中Ｋ与Ｐ的含量相近。（４）胚胎发育进程中，球果和种子的体积与养分含量在原胚和幼胚阶段（７月至９月中旬）的变化最大，以后渐趋平缓。

The growth and nutrition development of seed/cone of masson pine werestudied systematically during four years from l990 to l993.The results were as follows :( l )The cones of masson pine need two years to ripen。Formation period of young cone wasthat year after pollinating(in the first ten-day of April),rapid growth period was from June(before fertilizing)to the second ten-day of September in the second year,and riping periodwas from the last ten-day of September to October;2)In the growth period of 2-year-oldcone ,dry substance weight increased and water content decreased gradually.Both arrived atbalance point at the end of October,i.e. before the end of October the water weight sur-passed the dry substance and while after the end of October the dry substance surpassed thewater;(3)During the development of one-year-old cone,the change of N,K and P contentis similar to each other,and the N content of 2-year-old cone decreased gradually to be simi-lar to the K content.N and K content of seed are matched in July. Since then N content de-creased tiil riping period and was similar to P content in the second ten-day of October;(4)During the procedure of embryo development,the change of volume and nutrition content ofseed/cone were the greatest in the stage of proembryo and young embryo and then tended tolevel off gradually.