从染色体数目、幼枝的解剖特征探讨新疆的沙拐枣属内的某些进化关系

Studies on Chromosome Numbers and Anatomy of Young Branches of Calligonum of Xinjiang in Relation to the Evolution of Some Species of the Genus

 There are more than 20 species of Calligonum in China, of which 17 are known from Xinjiang.  They are divided into four sections.  This paper aims to study the evolutionary relations of some species of Calligonum in Xinjiang.  The chromosome numbers of 13 species and the anatomic structures of young branch of 8 species have been examined.                 Among 13 species, the, basic chromosome number x=9.9 species are diploids.  4 species are tetraploids.       The evolutionary relations of these plants are arranged as follows:      Section Calligonum (Fisch. et Mey.) Borszcz.                 1.  C. junceum (Fisch. et Mey.) Litv.       Section Pterococcus (Pall.) Borszcz.            2.  C. leucocladum (Schrenk) Bge.            3.  C. aphyllum (Pall.) Gürke.            4.  C. rubicundum Bge.       Section Calligonum   ,.     5.  C. cordatum Eug. Kor.            6.  C. densum Borszcz.                7.  C. klementzii A. Los.       Section Medusa Sosk et Alexandra            8.  C. mongolicum Turcz.                 9.  C. pumilum A. Los.           10.  C. ebi-nuricum Ivanova           11.  C. arborescens Litv.           12.  C. caput-medusae Schrenk           13.C. roborovskii A. Los.