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在高中生物教材中,四个必做的学生分组实验,有两个需要用到洋葱根。培养洋葱根的方法很多,但如何利用简便而又有效的方法,短期内培养出新鲜的洋葱根,是我们做教师的希望。我在多年的生物实验教学中,一直采用河沙培育发根,效果很好。 具体做法是:选取新鲜的洋葱鳞茎,首先去除老根。在水槽或其他容器中盛上一层河沙（厚度不少于5厘米）,然后使沙疏松一下,再把洋葱一个个放置在沙层上,根部向沙一面并使沙稍稍没过根部。然后从上面均匀地撒水,以使河沙保持潮湿。一般只需在室温条件下,每天或隔天在洋葱上撒少量水,水可顺着洋葱流至根部,这样即可满足幼根的发生和生长时对水分和氧的需要。根据实验需要,决定培根时间的长短。一般2～3天即可长出幼嫩的根,长度可达1厘米左右,培育一周根的长度均在5厘米以上。
In the high school biology textbooks, four must-do students group experiments, two of which require the use of onion roots. There are many ways to cultivate onion roots, but how to use simple and effective methods to cultivate fresh onion roots in the short term is our hope as a teacher. I have been using river sand to cultivate hair roots for many years in biological experiment teaching and it works well. The specific approach is: Select fresh onion bulbs, first remove old roots. Put a layer of river sand (not less than 5 cm in thickness) in a sink or other container. Then loosen the sand and place the onions one by one on the sand. The roots will be on the sand side and the sand will not pass through the roots. Then sprinkle water evenly from above to keep the river sand moist. Generally, just spray a small amount of water on the onion every day or every other day at room temperature. The water can flow along the onion to the roots, so that the need for water and oxygen can be met when the young roots are grown and grown. According to experimental needs, determine the length of Bacon. Usually 2 to 3 days can grow young roots, a length of up to 1 cm, the length of a week to cultivate roots are more than 5 cm.