台湾相思开花结实生物学特性研究

The Biological Characteristics of Flowering and Fruiting in Acacia confusa

通过实地观测,于2017—2018年连续2年对20～23年生台湾相思的开花结实性状进行调查,研究其生物学特性,掌握其生殖特性。结果表明:台湾相思的花蕾形成时间约在3月下旬末期,4月中旬中后期进入初花阶段;4月下旬末期达到盛花高峰期,5月下旬群体开花结束,整个花期持续时间约40 d。群体开花结束后,进入为期约40 d的零星小花期;幼果于4月下旬中后期初现,7月下旬果实全熟,整个果实生长期约90 d;花序一般在夜间开放,开花时雌蕊先于雄蕊伸展并成熟,为雌蕊先熟。开花当天14:00—16:00的柱头具有较高的活性,建议采用该时间段进行授粉;开花当天的花粉活力高达97.64%,花药在晴天时的散粉量明显高于其他天气,散粉高峰期后仍以较高水平(80%以上)持续,建议授粉时在晴天收集当天的花粉;台湾相思的自然花序结荚率较低,连续2年的自然结荚率皆不足25%,荚果含种量以6粒为主,7～8粒次之,稀2～3粒;瘪种数目随果荚含种量的增加而增加。

The flowering and fruiting conditions of 20-23 a Acacia confusa were investigated in 2017-2018 for consecutive 2 years by field observation.The biological and reproductive characteristics were studied.The results show that:The flower bud of A.confusa formed in late March,the middle and late period of mid-April came into the first flower stage,and the peak period was reached in the end of April.The flowering period of the colony was over in late May,the duration of the whole flowering period was about 40 d.After the end of colony flowering,the floret period entered into a sporadic floret period of about 40 d.The young fruit appeared early in late April.In late July,the fruit was ripe and the whole fruit growth period was about 90 d.Inflorescence usually opens at night.When pistil begins to expand and mature before stamen,pistil is prematured.The stigma of flowering is highly active at 14:00 to 16:00 on the day.It is recommended that pollination be done in this time period.The pollen viability of flowering on the day was as high as 97.64%,the amount of pollen dispersed in sunny days was significantly higher than that in other weather,and it continued at a high level(above 80%)after the peak.There fore,it is recommended to collect pollen on a sunny day during pollination.The natural pod rate of A.confusa is relatively low,and the natural pods rate for 2 consecutive years is less than 25%.The seed quantity of pod is mainly 6 grains,followed by 7-8 grains,and rarely 2-3 grains;The number of shrivelled seeds increased with the number of seeds contained in the pod.