夏蜡梅种子形态结构和种子萌发研究

为了解夏蜡梅种子形态结构和萌发特性,以其种子为研究对象,用体视显微镜结合石蜡切片法观察夏蜡梅种子形态和种胚的解剖结构,用称重法测定不同处理种子吸水率,并统计不同贮藏种子萌发情况。结果表明,夏蜡梅种子呈不规则纺锤状或长圆形,由种皮和胚两部分组成,属双子叶无胚乳种子;外种皮致密坚硬,深褐色、有光泽,透水能力较差,通过刻伤种皮,可显著提高吸水率;内种皮薄膜状,浅褐色,紧贴种胚;种胚发育较为成熟,白色或淡黄色,胚细胞富含淀粉粒,子叶发育良好,两片子叶相互卷合,胚芽分化不明显;湿沙冬藏处理可缩短种子萌发时间并显著提高发芽率,高达(72.22±6.44)%;刻伤种皮处理,可显著提高吸水率,从而打破休眠,提高其发芽率。研究表明,水分冲破种皮对破除夏蜡梅种子休眠和促进萌发极为重要。

Study on Seed Morphology and Seed Germination of Calycanthus chinensis

In order to understand the seed morphology and germination characteristics of Calycanthus chinensis,the seed morphology and anatomical structure of C.chinensis embryo were observed by using stereoscopic microscope combined with paraffin section,and seed water absorption under different treatments was measured by weighing method.Also,the seed germination under different storage conditions was also counted.The results showed that the seeds of C.chinensis were irregular spindle-shaped or oblong,composed of seed coat and embryo,and belonged to dicotyledonous seeds without endosperm.The outer seed coat was dense and hard,dark brown and shiny,with poor water permeability.By cutting the seed coat,the water absorption rate could be improved significantly,while the inner seed coat was thin,light brown,close to the seed embryo.The seed embryo was relatively mature,white or light yellow,and the embryo cells were rich in starch grains.The cotyledons were well developed,and the two cotyledons were rolled together,and the embryo differentiation was not obvious.The winterizing treatment with wet sand could shorten the germination time and significantly increase the germination rate,up to(72.22±6.44)%.Carving seed coat treatment could significantly increase the water absorption rate,thus breaking dormancy and increasing the germination rate.The results showed that water breaking through the seed coat was very important for breaking dormancy and promoting germination of C.chinensis.