【摘要】 作者对原产我国的野生菊5种和1变种、杂交种‘北京菊’1种(7个品种)、栽培菊21个品种进行了染色体数目和核型的比较观察。结果表明:香叶菊(Dendranthema boreale)和菊花脑(D.nankingense)为二倍体(2n=2x=18);西安野菊(D.indicum)、黄山野菊(D.indicum)、济南尖叶野菊(D.indicum var.acutum)、小红菊(D.erubescens)和北京菊(D.pekinense)均为四倍体(2n=4x=36);黄山紫花野菊(D.zawadskii)为六倍体(2n=6x=54);栽培菊(D.morifolium)品种多为六倍体至接近八倍体或异数多倍体(2n=52～71)。 作者还对上述种的核型特征进行了描述和比较,对部分种的小孢子母细胞减数分裂进行了初步观察,最后对上述种的倍性及核型的进化趋势进行了讨论。更多还原

【Abstract】 Florist’s chrysanthemum is indigenous to China and has been cultiv-ated in this country for more than 1,600 years. It becomes one of the most famous garden flowers over the world nowadays, but its origin is still a puzzling problem.This paper deals with the results of some cytological observations on several Chinese wild Dendranthema species and some chrysanthemum cul-tivars. The authors hope that the results found here may throw some light on solving the origin problem for florist’s chrysanthemums.Some wild Dendranthema species and races as well as 21 chrysanthemum cultivars of D.morifolium were studied cytologically. For most of the mate-rials, root-tip smears were prepared for cytological studies. Only a few pollen mother cells of D. inaicum and D.morifolium cv.’Hang Bai Ju’were smeared for meiotic observations. Measurements of karyotypes were carried out according to Levan’s method.After a series of cytological observations,we found two diploid species (2n = 2x = 18), viz. D. boreale and D. nankingense; five tetraploid materils (2n = 4x = 36), viz. D.indicum (Xian), D.indicum(Huang Shan),D. indicum var.acutum(Jinan),and D. erubescens and D.pekinense(D.indicum var. acutum × D .erubescens) one hexaploid species(2n = 6x = 54)viz. D. zawadskii (Huang Shan).Most of the chrysanthemum cultivars were found to be hexaploids and aneuploids.Chromosome counts were made for each of the 21 cultivars with results falling into three groups : (l)small-flowered chrysanthemums, early chrysanthemums, and a few big-flowered cultivars ( ’Lion picture’, ’Flying Beauty’ ) mostly with 54 chromosomes ( or plus or minus one); ( 2 ) big-flowered chrysanthemums mostly with 54 chromosomes, but varying between 52 and 57 (examples: cv.’Brilliancy’,’Dragon’s Claw’, ’Hanging Silks’, and’Red Anemone’); ( 3 )some big-flowered chrysanthemums with chromosomes varying approximately from 6x to 8x, or 2n = 58~71(examples: cv.’Green Tree-Peony’, ’Pink Lotus’, ’Rainy Helianthus’, and’Hero’s Flag’ ) .Karyotypes of the diploid, tetraploid and hexaploid as well as aneuploid species and cultivars were studied and table of measurements made.更多还原