Chromosome Preparation and Karyotype Analysis of Distylium chinense (Fr.) Diels
In present study,we compared that the different methods about sampling time,the pretreatments, fixatives,dissociations time and dyeing in chromosome preparation of Distylium chinense CFr, ) Diels.an endemic tree species in China ,on the root tips. The results showed that the best experimental protocol for karyotype analysis of D. Chinense was the better sampling time at 9:00～11:00 a. M. And 13 :00～15:00 p. M. ,the better pretreatment with saturated p-dichlorobenzene for 3 h.the better dissociation way with 1 mol·L-1 HC1 at 60℃ for 8 min,and dyeing time for 10 min with modified carbolic acid-magenta. Consequently,chromosome numbers and karyotype of D. Chinense was reported for the first time with the best experimental protocol for karyotype analysis. The somatic cell chromosome number of D, chinense at meta-phase is 2n-2x=24,the basic chromosome number is x=12. Karyotype formulae is 2n=24=12m(2SAT) + 10sm+2st,mainly consisting of metacentric and submetacentric chromosomes. Chromosome composition of relative length is 2n = 24 = 2L+8Mz +12M, +2S.its index of As. K% is 64. 29%,and ihe karyotype a-symmelry belongs to "2A" type. These results revealed karyotype of D. Chinense is symmetrical to a higher degree,indicating that D. Chinense belongs to a relatively primitive type and relatively old or the original plant in evolutionary processes.
NETL
NSTL
万方数据
维普
