美洲商陆果实和种子组分测定及幼苗形态观察

Composition analysis of seeds and fruits and morphological observation of seedlings in Phytolacca americana

为给美洲商陆的综合利用提供基础资料,对美洲商陆果实和种子的大小与组分进行了测定,并对其幼苗形态进行了观察。结果表明：1美洲商陆果实为扁球形肉质浆果,紫黑色,横径长0.97～1.10 cm,纵经长0.75～0.80 cm,梗长1.02～1.18 cm,平均单粒质量为0.54 g,内含种子8～12粒不等;种子呈肾圆形,黑色而具光泽,为双子叶有胚乳种子,子叶及胚线型,种子的长度与直径平均分别为3.089和2.843 mm,平均单粒质量为9.9 mg,属小型种子。2美洲商陆果肉中的红色素的质量分数为0.597 mg/g,高于总糖（0.423 mg/g）、游离氨基酸（0.044 mg/g）、蛋白质（0.057 mg/g）等营养元素的含量。3美洲商陆种子中的粗脂肪含量最高,其质量分数为137.419 mg/g,大大高于总糖（0.423 mg/g）、游离氨基酸（0.006 mg/g）和蛋白质（0.008 mg/g）的含量;同时还含有Ca、Mg等种矿质元素。4美洲商陆幼苗为子叶出土型幼苗,室温、沙培条件下约需20天的时间才能萌发,平均出苗率为60.55%;子叶2片对生,椭圆形或卵状椭圆形,上面绿色,下面淡紫红色;上胚轴紫红色,下胚轴的上部与下部分别为紫红色和姜黄色;初生叶1枚,阔椭圆形,上面绿色,下面淡紫红色;次生叶互生,卵形,第1～2片次生叶的上面呈绿色,下面淡紫红色,第3片叶开始逐渐变成叶两面均为绿色;茎为紫红色。

In order to provide some basic data for comprehensive utilization of Phytolacca americana, sizes and compositions of fruits and seeds in P americana were determined, and morphological characteristics of seedlings were observed. The results showed that： ①The fruit of P americana was a purple-black oblate spheroid and belonged to a fleshy berry. The transverse diameter of fruit was 0.97-1.10 cm, the longitudinal diameter was 0.75-0.80 cm, and the stem length was 1.02-1.18 cm. Mean single fruit mass was 0.54 g and it contained 8-12 seeds. The seed was round reniform, black and lucidus, and it belonged to dicotyledon and albuminous seed. The cotyledons and embryo were linear. The seed length and diameter were 3.089 and 2.843 mm respectively, and the mass per seed was 9.9 mg, so it was of small size seed. ② The mass fraction of haematochrome in flesh was 0.597 mg/g, higher than the total sugar content （0.423 mg/g）, free amino acid content （0.044 mg/g）, protein content （0.057 mg/g） and so on. ③The mass fraction of crude fat in seeds was 137.419 mg/g, higher than the total sugar content （0.423 mg/g）, free amino acid content （0.006 mg/g） and protein content （0.008 mg/g）. The seeds contained plenty of mineral elements, such as Ca and Mg.④ Seedlings in P americana belonged to cotyledon excavated type. It need take about 20 days for seed germinating under the conditions of sand culture and room temperature, and the mean seed germination percentage was 60.55%. There were two opposite cotyledons in every seed. The cotyledon was oval or ovate-elliptic, green upside and light fuchsia downside. The epicotyl was fuchsia, and the upside and underside of hypocotyl were fuchsia and ginger respectively. There was only one primary leaf and it was broadly elliptic, green upside and light fuchsia downside. The secondary leaf was alternate and oval. The first and second secondary leaves were green upside and light fuchsia downside. The third secondary leaf was green on both sides. The stem was fuchsia.