观察长穗偃麦草(Thinopyron elongatum)体细胞染色体制片的好方法

观察二倍体长穗偃麦草的染色体一直是个难题,以二倍体长穗偃麦草种子(Thinopyron elongatum =E.elongata,2n=14 EE)为实验材料,对实验方法进行了改进,发芽前浸种处理24 h,将发芽时间和促芽生长时间分别延长至90～96 h,并对第一轮未萌发的种子进行二次萌发,使种子萌发率达到97%以上.取上述萌发处理后的种子进行根尖染色体制片,结果表明染色体中期分裂相多,染色体分散良好,形态特征清晰,显然,这是一种开展长穗偃麦草细胞学研究的有效方法.

A Modified Method for Observing Chromosomes in the Root-tip Cell of Thinopyron elongatum

So far, there is a diffi cult problem for observing the chromosomes of diploid Thinopyron elongatum (2n=14 EE). We developed a chromosomal preparation method of root-tip cell by improving a seed germinating procedures, which was proved to be the easy processes in diploid Thinopyron elongatum. At first, seeds were soaked in water at room temperature for 24 h, and then the germination time and gemma growth time extend to 90 to 96 h respectively, which would be easy to get germinating seeds up to 97% by re-treated the non-germinated seeds. We did the experimemnts of chromosomal specimens by using the root-tip cell of germinating seeds treated with above procedures. The primary results showed that the modif ied process could easily get more metaphase cells, well decentraztions and clear morphological characters of chromosome. It is obvious that the modified menthod would be alternative approach for cytological studies in Thinopyron elongatum.