本文旨在探討愛玉與薜荔,二種在分類地位極為相近之植物,其果實之形態與其生化特性之異同。二者隱花果之大小及重量差異明顯,愛玉的果實長寬分別為8.4×4.6cm,而薜荔則為4.6×3.4cm。愛玉與薜荔果實內每克乾瘦果所含有之果膠量與果膠上所攜帶之甲氧基量大約相同。二者果膠可能絕大部份均呈甲氧基化,因為愛玉與薜荔之甲氧基/果膠比值分別為13.1%與14.0%。分析瘦果外果皮之果膠酯酶活性發現二者均變化很大。一般而言,愛玉瘦果所含之果膠酯酶活性較薜荔要高出甚多,如本試驗所顯示的,每克乾瘦果可以抽取的果膠酯酶活性分別為95.8與4.2固酵素活性單位。二者果膠酯酶之生化性質亦加以研究比較,以免疫轉印方法獲知愛玉與薜荔之果膠酯酵具有相同之分子量,而且免疫上的反應並無不同,此即顯示二者可能為極相似或相同之蛋白質。有一點極為有趣的發現是愛玉含有二型的果膠酯酶,而薜荔則僅具單一的果膠酯酶。
Ficus awkeotsang and Ficus pumila, both are related in taxonomical deposition, were compared in terms of morphological and biochcmical characters. The sizes of syconium of both species are quite different in length and width with a measure of 8.4×4.6 cm and 4.6×3.4 cm, respectively. Therefore, the quantity of the fresh achenes in the syconium of both species differ significantly also. Both species have the same quantity of pectin and methoxy content in each gram of dried achenes. Majority of the galacturonic acid of both species are methoxylated, since the methoxy/pectin ratio of Ficus awkeotsang and Ficus pumila is 13.1% and 14.0% respectively. Pectinmethylesterases in the pericarp of achenes are very different in activity in both species. In general, Ficus awkeotsang has much higher pectinmethy-lesterases activity than Ficus pumila, for example, they are 95.8 and 4.2 activity units in each gram of dried achene, respectively. Using SDS-polyacrylamide gel electrophoresis and immunobloting analysis, pectinmethylesterases of Ficus awkeotsang and Ficus pumila showed the same molecular weight and were highly similar in immunoreactivity. This indicates that pectinmethylesterases may be very similar or even the same protein in both species. A new finding is there are two isoforms of pectinmethylesterase in Ficus awkeotsang and only one in Ficus pumila.