广西植物Issue(3)：378-383,6.DOI:10.11931/guihaia.gxzw201401027
大鹅观草与蛇河披碱草属间杂种的细胞遗传学研究
Cytogenetic study on intergeneric hybrids between Roegneria grandis and Elymus wawawaiensis
摘要
Abstract
To investigate the genomic constitution of Roegneria grandis (2n=4x=28)and to provide cytological evi-dence for the taxonomic treatment of R .grandis ,artificial distant hybridization between R .grandis and Elymus wawawaiensis (2n=4x=28)was carried out.Three F1 hybrid plants were obtained successfully.The general mor-phological appearance of the intergeneric F1 hybrid was intermediate between the Roegneria grandis and Elymus wawawaiensis .For estimation of pollen fertility study,pollen grains of hybrids were examined after staining in I2-IK solution.Pollen grains of parental species were highly fertile.The percentage of stained pollen grains of Roegeriagrandis reached 94.6%,and 90.5% pollen grains of Elymus wawawaiensis were fertile.Pollen grains of the hybrid between Roegeria grandis and Elymus wawawaiensis were sterile.Chromosome pairing at meiosis metaphase I(MI) of Roegeria grandis and Elymus wawawaiensis and their F1 hydrid were analyzed.Meiosis of the parental tetraploid species was quite regular with 14 bivalents.Most of them were ring bivalents.A low frequency of univalent(0.04/cell)was observed in Roegeria grandis .Chromosome pairing at meiosis metaphase I(MI)was observed in 83 MI cells in the F1 hybrid.Meiotic pairing in the F1 hybrid averaged 6.46 bivalents per cell,varying from 5 to 8.7 biva-lents occurred in 35.2% of the MI cells,42.59% of the MI cells had 6 bivalents,and 8 bivalents were observed in several MI cells.All the metaphase I cells contained unpaired chromosomes,ranging from 10 to 18,with a mean of 14.66 univalents per cell.0.14 trivalents per cell were observed.The meiotic configurations of the F1 hybrid were 14.66 I+6.46 II+0.14 III.The chiasmata per cell were 9.83 with C value of 0.35.The results were as follows:(1) Roegeria grandis and Elymus wawawaiensis shared a homologous St genome.The other genome of Roegeria gran-dis was not St or H genome.The genome constitution of R .grandis was not StStg genome;(2)A low frequency of trivalents(averaged 0.14 per cell)were observed in the F1 hydrid.They can probably be attributed to structural rear-rangements between chromosomes of R .grandis and Elymus wawawaiensis ,or a certain degree of homoeology be-tween the St and Y genomes in these species.Further study needs to be done to investigate the oringin of Y genome;(3)The homology of St genome of Elymus species from different geographical origins with the St genome of Roege-ria grandis was different.Elymus lanceolatus and E .wawawaiensis were from north America,and E .sibiricus and E .caninus were from Asia.The homology of St genome of Roegeria grandis with the St genome of Elymus species from north America was higer than that with the St genome of Elymus species from Asia.The reason remained to be discussed in the future.关键词
大鹅观草/蛇河披碱草/属间杂种/染色体配对/亲缘关系Key words
Roegneria grandis/Elymus wawawaiensis/intergeneric hybrid/chromosome pairing/homology分类
农业科技引用本文复制引用
杨财容,张海琴,沙莉娜,周永红..大鹅观草与蛇河披碱草属间杂种的细胞遗传学研究[J].广西植物,2015,(3):378-383,6.基金项目
国家自然科学基金(30901052,31270243) （30901052,31270243）
