Study On Karyotype Analysis And Drought Resistance Of Two Rescue Grass Species(Bromus Catharticus Vahl.)

The chromosomes of Bromus cartharticus Vahl.and rescuegrass Qian cao No 3 were observed by microscopy and the chromosomes were analyzed by Adobe firework software.(1)The chromosome ratio of the ratio of 2n = 2x = 42 = 2M + 38 m + 2sm(1sat),the chromosome ratio of the arm ratio greater than 2 is 4.8%,the karyotype asymmetry coefficient is 56.0%,and the karyotype belongs to "2B".(2)The karyotype formula of the grass is 3n = 2x = 28 = 2M + 18 m + 8sm(2sat),the maximum and shortest chromosome ratio is 2.69,the chromosome ratio of the arm ratio is greater than 2 is 7.1%,the karyotype is asymmetric Coefficient of 60.0%,karyotype is "2A".The drought-resistant seeds of the seeds were treated with 5%,10%,15%,20%,25%,30% and 35% PEG.Physiological indicators include germination rate,relative germination rate,germination potential,relative germination potential,germination index,drought and drought germination index,vigor index,dynamic drought index.The results show:(1)The dynamic drought resistance index and germination drought index of wild Bromus inermis were higher than that in Guizhou grassland.The vigor drought index of seed could express the ability of drought resistance and seed germination stage.In the germination stage,the drought resistance index of the cultivars with poor drought resistance is generally low(Guo Zhihua et al.2007).Therefore,the drought resistance of wild Bromus inermis is higher than that of Guizhou grass Growing in the environment.(2)The relative germination rate of Bromus tabacum was increased by 15% and 25%,indicating that under the osmotic stress,the germination of wild Bromus inermis was promoted.15% under osmotic stress to grow better.The relative germination rate of Ficus microcarpa L.was increased only when the concentration of PEG was 15%,so when PEG concentration was 15%,it was more favorable for the growth and development of.(3)The relative radicle length and relative germ length of wild Bromus tabacum were the highest when PEG concentration was 15%,and when the PEG concentration was 15%,the growth of radicle and germ The The relative radicle length of Ophiopogon japonicus 3reached the maximum at 10%,and reached the maximum at 5%,indicating that 5% PEGfavored the growth of the germination of Bromus tabacum L.% PEG favors radicle growth.(4)The effect of PEG-6000 on wild Bromus is more obvious,and when PEG concentration is 15%,it is more suitable for the growth and development of wild Bromus inermis.The effect of PEG-6000 on the germination period of Bromus tabulaeformis was not obvious.