【摘要】 <正> 一、引言 石蒜属Lycoris Herb.全世界约有20多种,其中已做过细胞染色体计数者计有17种。本文继红蓝石蒜Lycoris haywardii Traub和换锦花L.sprengeri Comes exBaker以及长简石蒜L.longituba Y.Hsu et Fan,玫瑰红石蒜L.rosea Traub etMoldenke,石蒜L.radiata(L′Her.)Herb.和矮小石蒜L.radiata var.pumila Grey(以上均待发表)之后,对安徽石蒜L.anhweiensis Y.Hsu et Fan和中国石蒜L.chinensis Traub的染色体进行计数和核型的描述和分析,旨在为今后探讨石蒜属的核型进化和种系发生提供必要的资料。更多还原

【Abstract】 The present paper deals with a study of the karyotypes of two species ofthe genus Lycoris Herb. -L. anhweiensis Y. Hsu et Fan and L. chinensisTraub, The number of chromosomes in root-tip cell of these two species has been found to be K(2n) = 16 (Fig. 1 and 2), both species exhibited bimodal karyotypes with 6 V-shaped and 10 I (rod) -shaped chromosomes each. According to Levan et al.[8], the karyotype formulas of L. anhweiensis and L. chinensis are therefore K (2n) =16= 6 m + 4t + 6t(SAT) and K (2n) = 16 = 6m + 6t+2t (SAT) respectively. The chromosome count and karyotype of the former species is reported for the first time.Upon a comparison of the karyotype data shown in Table 1 , it is found that these two species are very similar in both arm ratio and total length of chromosomes, but differ from each other in the number of satellites. But the recording of satellites is problematical because they arc often very variable in appearance, and it is not always possible to obtain consistent results. The presence of "small v" type chromosomes reported by Bose[3,4] in the karyotype of L. chinensis have not been found in our observations.Inariyama[6], Stebbins[6], and Jones[7] in particular have held that 11 be the basic chromosome number and a phylogenetic decrease in chromosome number through successive Robertsonian translocation be the predominant trend of karyotype evolution in Lycoris. In this case, L. anhweiensis and L.chinensis should be considered as taxa which are highly specialized in karyotype evolution of the genus.Yet the above two species differ remarkably with respect to their floral sturctures, and according to Traub’s classification, they belong to two different subgenera. This shows that increasing karyotypical specialization is not always associated with increasing morphological specialization, particularly with respect to floral characteristics in the genus Lycoris.更多还原