辽宁兴城油松种子园无性系开花习性的研究

1982—1984年在辽宁兴城种子园,3年的观测表明,49个无性系花期早晚和长短有较大差别。这与无性系本身的特性、花期前的积温、花期内的温度和湿度以及球花着生部位等有关。由于种子园中有部分无性系花期不遇,由此減少的杂交组合至少在1/10以上。嫁接后第九年雌球花产量较上年成倍增加,到第10年总产量仍持续上升,但早期结实量大于平均水平的约30％无性系,雌球花产量已有下降趋势。 迄今种子园中开花株数和雄球花产量稳定增长,多数无性系植株平均着花量约在700个上下,但仍有约半数无性系的1/3植株尚未开雄球花。种子园中花粉量不足,每公顷约产花粉2.8—3.7公斤,且种子园各无性系花粉比例极不平衡,5个无性系的雄花量占总量的一半以上。

STUDY OF FLOWERING HABIT OF PINUS TABULACFORMIS CARR.IN THE SEED ORCHARD LOCATED IN XINGCHENG COUNTY LIAONING PROVINCE

Three year(l982-1984) observations on flowering in the pine seed orchard revealed quite large-differences in flowering date and duration among 49 clones.The differences were related with scme characteristics of clones, the cumulative temperature before flowering, the temperature and moisture conditions during flowering, and the location of flowers in thecrown.Flowering time of different clones in the seed orchard overlapped only in part and, therefore, at least a reduction of 10% of total possible cross combinations would be met. The conelet production at the 9th year (1983) afte grafting increased dramatically to twofold of that in 1982,and still increased at the 10th year. However, about thirty precent of the clones whose cone production were above the average level in 1983 tended to reduce the production in 1984. The number of floweing trees arid the production of male flbwers in the seed orchard increased- steadily. There were about 700 male flowers per bearing tree for most of clones, but 46％ of clones had 1/3 ramets bearing no male flower at all. Pollen production in the seed orchard was estimated to be 2.8-3.7kg/ha which was apparently not sufficient for normal pollination. In addition, bollen composition in the seed orchard was extremely unbalanced, as the amount of pollen from the 5 clones was more than half of the total pollen in the seed orchard