英德火炬松改良种子园无性系开花的时空变化

对英德火炬松改良种子园建园无性系的开花习性进行了观察，发现大部分无性系雌、雄花发育良好。无性系开花时间大约在3月4～26日，大多数无性系雌花在3月7—8日开始开放，少数在3月4～6日开始开放，雄花大多数在3月9～10日开始开放。总体上雌花比雄花早2～3d开放，早1～2d结束。全园雌花盛花期为3月8～17日，雄花盛花期为3月12～19日，雌、雄花盛花期有一个星期的时间相遇，自然条件下可保证充分授粉。种子园嫁接后第2年到第3年，90％以上的无性系开花，平均开花株率略高于70％；从第3年到第4年，100％的无性系开花，开花株率接近95％。说明嫁接后第3～4年，是种子园进入盛产的关键时期，也是实施人工控制授粉的有利时期。

The Time and Spatial Variation in Blossom of Clones in Yingde Loblolly Pine Advanced Seed Orchard

Investigation was carried out to survey the blossoming characteristics of clones in Yingde loblolly pine (Pinus taeda) advanced seed orchard. It was found that most of the clones develop male and female cones well. Time of flowering is the period from 4th-26th March. Most of the clones start blossoming of female cones in 7th -8th and a few clones start in 4th-6th March. For male cones, most of the clones start in 9th-10th March. In general, female cones start blossoming in 2-3 days earlier and end 1-2 days earlier than male cones. Time of full blossom in the whole orchard is 8th-17th March for female cones, and 12th-19th March for male cones. Full blossoming times for female and male cones meet in a period of one week. This ensure the blossoming female cones be fully pollinated. From the 2nd-3rd year after grafting, more than 90% of the clones had blossomed, and then the blossoming ramets accounted for more 70% of the total in average. The figures became 100% and nearly 95% in 3rd-4th year. These results showed that the period of 3rd-4th year after grafting is key since the orchard was entering the age of full production. It is also important for practice of control pollination.