1975年,赫尔曼(Herman)等报道,由咖啡叶愈伤组织培养出的完整小植株能无性繁殖及再生。1970年,奥古图格(Ogutuga)等从茶树茎切片衍生的愈伤组织中,特别研究了嘌呤生物碱的形成。他们发现其咖啡因含量为其干重的0.1%。1972年凯勒(Keller)等人在做小粒种咖啡果皮和胚乳的愈伤组织培养中,其咖啡因含量高达2%,而 In 1975, Herman et al. Reported that intact plantlets cultured from coffee leaf calluses could asexually propagate and regenerate. In 1970, Ogutuga et al. Studied in particular the formation of purine alkaloids from callus derived from tea stems. They found that their caffeine content was 0.1% of their dry weight. In 1972, Keller et al. Used calluses of small-seed coffee peel and endosperm in a caffeine content of up to 2%