冰草形态学与细胞学的研究

Study on the morphology and cytology of Agropyron cristatum

冰草(Agropyron cristatum)是异花授粉植物,种群内株丛间变异较大,存在着丰富的遗传多样性。研究表明,冰草形态方面存在多种变异类型,地下茎形成了疏丛型、疏丛-根茎型、根茎型3种类型;叶片表皮被毛有上下表皮均密被刺毛,上表皮被较密微毛、下表皮被较少微毛,上表皮被少微毛、下表皮光滑无毛变异类型;种子外稃有密被长柔毛、疏被短柔毛、光滑无毛变异类型。染色体研究查明,冰草染色体存在二倍体和四倍体2个倍性水平,二倍体冰草染色体为14条,核型公式为2n=14=10m(1sat)+4sm(2sat),核型类型为1A型;四倍体冰草染色体为28条,核型公式为2n=28=22m+6sm,核型类型为1A型。

Agropyron cristatum belongs to cross-pollination plants.The Characters of this kind of plants are big variation between strains in populations and rich genetic diversity.Research showed that A.cristatum form had many variation types;the three types of subterranean stem were axial root type,axial-rhizome type and rhizome type;the types of leaves epidermis covers were upper and lower epidermis of leaves with dense bristle,upper epidermis of leaves with much fuzz lower epidermis of leaves with a little fuzz,upper epidermis of leaves with little fuzz and lower epidermis of leaves with no fuzz;the types of seeds lemma were dense villus,spacing pubescence and hairless and glabrous etc.types.Research on chromosome showed that the chromosomes of A.cristatum had two ploidy levels of diploid and triploid types.The number of diploid chromosome of A.cristatum was fourteen.The karyotype formula was 2n=14=10m（1sat）＋4sm（2sat）The karyotype type was 1A;the number of tetraploid chromosome was twenty-eight;the karyotype formula was 2n=28=22m＋6sm and the karyotype type was 1A.