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一、植物的描述(一)营养器官珍珠粟(Pennisetum typhoides Burm.)为一年生禾本科植物,株高1.50～2.50米。直生主根很快长出次生根和三生根。种子萌发后三、四周,就从根颈长出第一轮不定根,并且不定根的数量很快超过最后趋于消失的初生根。随后从根颈以上的节上陆续长出第二轮、第三轮有时甚至第四轮不定根。只有最靠近表土的不定根才能扎入土内而生长良好,其他的不定根则在未碰到土壤之前就已停止生长。
First, the description of the plant (A) vegetative organs Pearl millet (Pennisetum typhoides Burm.) Annual gramineous plants, plant height 1.50 ~ 2.50 meters. Straight born root quickly grow secondary root and root of trios. After three or four weeks of seed germination, the first round of adventitious roots was grown from the root neck, and the number of adventitious roots soon exceeded that of the primary root which tended to disappear. Then from the root of the neck above the section gradually grow the second round, and sometimes the third round of the fourth round of adventitious roots. Only the adventitious roots closest to the topsoil can grow well in the soil and the other adventitious roots stop growing before they reach the soil.