A Study On Genetic Diversity Of Musella Lasiocarpa Populations

Musella lasiocarpa is under Musella genera in Musaceae family. It is a perennialherbaceous and big-sized tuft. There is only one species in the genera and particularlydistributes in China. Its habitat usually is mountain slop at the elevation of 1500-2500 Km inthe middle and at the west of Yunnan province. Based on population genetics principles andmethods,the patterns of morphological varitation,karyotical variation and RAPD variation wereinvestigated in twelve population of M. lasiocarpa. The research attempted to provide the datato further profound study on the genetic variation and evolution of this plant. The results weresummarized as following:1. Morphology variance analysis: The twenty-two morphological features were observedin twelve populationsof M. lasiocarpa. Their coefficients of variations were distributed mainlyfrom 0.07 to 0.65. The difference of twenty-one traits among populations is significant. Thecoefficient of variations of the seed traits is the lowest while of the nutrition traits is the highest.The coefficient of variations of the nutrition traits is 0.38. The coefficient of variations of theinflorescence traits is 0.13. The coefficient of variation of the fruit traits is 0.19. The coefficientof variations of the seed traits is 0.08. The mean of the variations coefficients of themorphologic traits is 0.20. Neasted analysis of variance indicated that about 33.37% of themorphological variability is attributed to the differentiation among the populations and theremaining 61.98% resided within the populations. M. lasiocarpa has obvious polymorphism inpopultions.2.Karyotype analysis: The karyotypes of twelve populations were investigated in thepresent paper.The karyotype of WL,LH population was formulated as 2n=18=12m+6sm,belongingto Stebbins'2A type; The karyotype of HM, XR, HQ population was formulated as2n=18=16m+2sm,belonging to Stebbins'lA type; The karyotype of GS population wasformulated as 2n=18=14m+4sm,belonging to Stebbins'lA type; The karyotype of AXpopulation was formulated as 2n=18=4T+12m+2sm,belonging to Stebbins'2A type; Thekaryotype of YM,HC population was formulated as 2n=18=2T+16m, belonging toStebbins'2A and 1A type; The karyotype of DZ population was formulated as2n=18=18m;belonging to Stebbins'1A type. The karyotype of LH population was formulatedas 2n=18=12m+6sm(SAT),belonging to Stebbins'2A type; The karyotype of SJ population wasformulated as 2n=18=12m(SAT)+6sm,belonging to Stebbins'2A type; The chromosometranslocation and inversion result in the variance of relatively length index and arm ratio. 3. RAPD analysis: Random amplified polymorphic DNA (RAPD) was amplified to studythe genetic diversity and genetic structure of Musella lasiocarpa based on twelve wild andcultivated populations. Ten primers were screened to use, and 88 bands were amplified, amongwhich 85 were polymorphic. At specific level, the percentage of polymorphic bands, Nei'sindex and Shannon information index were 96.59%, 0.2890 and 0.4416. The total genedifferentiation (Gst) was 0.5682, which indicated 43.13% of genetic variation resided withinpopulations and a slightly high degree of genetic variation occurred among populations. TheNei's genetic identity among populations ranged from 0.66 to 0.95. The results from clusteranalysis showed that the genetic distance among wild populations was close, which wasconsistent with their geographical distribution pattern; the genetic distance among cultivatedpopulations was far and was not consistent with their geographical distribution pattern.