同一生境下多年生黑麦草与节节麦的核型比较

对同一生境下多年生黑麦草（Lolium perenn L.）和节节麦（Aegilops squarrosa L.）的根尖细胞染色体作了分析,并从细胞学角度比较了两者的同源性。结果表明：多年生黑麦草的核型公式为：2n=6x=42=24m＋18sm（2SAT）,属于六倍体的＂2B＂型,在第19号染色体上有一对随体,最长与最短染色体的比为2.13,臂比大于2的染色体占全套染色体的30%,核型不对称系数为60.48%;节节麦的核型公式为2n=2x=14=10m＋4sm（2SAT）,属于二倍体的＂2A＂型,在第4号染色体有一对随体,最长与最短染色体长度比为1.49,臂比大于2的染色体占全套染色体的14%,不对称系数为58.2%,表明同一生境下多年生黑麦草比节节麦更为进化,两者在染色体水平上没有亲缘关系。

Chromosome karotype comparative of Lolium perenn and Aegilops squarrosa in the same habitat

The RTC （ root tips cell ） chromosomes of Lolium perennang L. and Aegilops squarrosa L. in the same habitat were analyzed. Their homology was discussed based on the morphology. The results showed that the karyotype formula of Lolium perenn L. was 2n = 6x =42 =24m ＋ 18sm（2SAT） , belonged to ＂2B＂ type which was hexaloid. There was a pair of SATS in No. 19 chromosome. The chromosome length ratio was 2.13, the chromosome ratio of the arm ratio 〉2 was 30%. The index of asymmetry was 60.48%. The karo-type formula of Aegilops squarrosa was 2n =2x ： 14 = 10m ＋4sm（2SAT） , belonged to ＂2A＂ type which was diploid, there was a pair of SATS in No. 4 chromosome; The chromosome length ratio was 1.49 ; the chromosome ratio of the arm ratio 〉2 was 14%. The index of symmetry was 58.2%. The results are as follows： according to both the number and shape characteristic of the chromosome, all aboves show that Lolium perenn L. has more evolution than Aegilops squarrosa L. in the same habitat and they are not genetic relationship on the chromosome level.