title: The chromosome number, karyotype and genome size of the desert plant diploid Reaumuria soongorica (Pall.) Maxim.
abstract: Extreme drought and salt resistant plant Reaumuria soongorica is of great potential for revealing genetic bases unique to naturally stress-tolerant plants. A preliminary genome survey, including chromosome number, karyotype, chromosomal localization of 45S rDNA loci and genome size was conducted with R. soongorica collected from Lanzhou, China. Chromosome counting showed that R. soongorica is diploid with chromosome number of 22. Karyotypical analysis illustrated that the chromosomes size ranges from 3.38 to 5.51 μm, and the chromosomal formula is 2n = 2x = 22 = 4 m + 14sm + 4st. Fluorescence in situ hybridization revealed that four pairs of 45SrDNA signals were detected at the end of R. soongorica chromosomes. The flow cytometry analysis indicated that the mean C value of R. soongorica is 0.806 pg with predicted genome size of about 778 Mb. The results indicate that the extreme drought and salt resistance of R. soongorica was not attributed to a big and complicate genome and also offer some clues in resolving the problems of taxonomy and evolution in Tamaricaceae.
authors.affiliation: Key Laboratory of Eco-hydrology and of Inland River Basin, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, 320 Donggangxilu, Lanzhou, Gansu 730000, China. wangxiaohua950@126.com
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Wang
authors.forename: Tao
authors.initials: T
authors.lastname: Zhang
authors.forename: Zengnan
authors.initials: Z
authors.lastname: Wen
authors.forename: Honglang
authors.initials: H
authors.lastname: Xiao
authors.forename: Zujun
authors.initials: Z
authors.lastname: Yang
authors.forename: Guoxiong
authors.initials: G
authors.lastname: Chen
authors.forename: Xin
authors.initials: X
authors.lastname: Zhao
mesh_terms: D002681:China; D032461:Chromosomes, Plant / Q000235:genetics*; D004275:DNA, Ribosomal / Q000235:genetics; D003889:Desert Climate; D004171:Diploidy; D017753:Ecosystem; D005434:Flow Cytometry; D018745:Genome, Plant / Q000235:genetics*; D005843:Geography; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D008677:Metaphase; D012275:Oryza / Q000235:genetics; D032363:Tamaricaceae / Q000033:anatomy & histology / Q000235:genetics*
chemical_list: D004275:DNA, Ribosomal