五角菟丝子和向日葵列当,分属于菟丝子属 Cuscuta 和列当属 Orobanche。菟丝子属植物的叶绿体片层少,RUBP 化酶(光合酶)活性小,几乎全靠从寄主植物(如大豆、花生、柳等)的茎、叶中吸收水分和养分,称为茎、叶全寄生植物;列当属植物不含叶绿素,全靠从寄主植物(如向日葵、烟草、西瓜、哈密瓜等)根中吸收养分和水分,称为根全寄生植物。由于全靠寄主而生活,全寄生植物为害重,防除困难,引起了科学工作者广泛重视和研究。要对这些全寄生杂草进行研究,关键一步就是要对这些杂草种子进行萌芽的诱 Pentagon dodder and sunflower column, belonging to the Cuscuta Dodder and Orobanche. Dusky plants chloroplast layer less, RUBP enzyme (photosynthetic enzyme) activity, almost entirely from the host plants (such as soybeans, peanuts, willow, etc.) stems and leaves to absorb water and nutrients, known as stems, leaves all Parasitic plants; Coltsfoot plants do not contain chlorophyll, all from the host plants (such as sunflower, tobacco, watermelon, cantaloupe, etc.) root absorption of nutrients and water, known as the root of all parasitic plants. Due to the living by the host, all the parasitic plants are seriously weakened and the prevention and control difficulties are caused, which has aroused extensive attention and research by scientists. To study these all-parasitic weeds, the key step is to induce these weed seeds to germinate