部分广义菊属野生种染色体制片体系优化与核型分析

The chromosome sectioning optimization and karyotype analysis of wild species of some Chrysanthemum and related genera

采用8-羟基喹啉和冰水混合物,按不同时间对广义菊属内7个野生种质根尖进行预处理,设置解离时间梯度,获得每种野生种最优解离时间。结果表明:广义菊属内7个野生种质经过冰水混合物24 h预处理,可得到分散良好,形态正常,便于统计的高质量染色体制片;最适宜的解离时间为:灌木亚菊为12.5 min,甘菊和太行菊为12 min,神农香菊、野菊和小红菊为11 min,毛华菊为14 min;得到了7个野生种的核型公式。灌木亚菊(Ajania fruticulosa)核型公式为2n=2x=18=16m+2sm,1B,核型不对称系数为57.26%;甘菊(Chrysanthemum lavandulifolium)核型公式为2n=2x=18=17m+M,1A,核型不对称系数为53.71%;太行菊(Opisthopappus taihangensis)核型公式为2n=2x=17=14m+2M+sm,1A,核型不对称系数为54.95%;神农香菊(Chrysanthemum indicum var.aromaticum)核型公式为2n=2x=18=15m+2sm+M,2A,核型不对称系数为56.86%;野菊(Chrysanthemum indicum)核型公式为4n=4x=36=31m+3sm+2M,2B,核型不对称系数为56.28%;小红菊(Chrysanthemum chanetii)核型公式为4n=4x=36=25m+8sm+2T+M,2B,核型不对称系数为58.95%;毛华菊(Chrysanthemum vestitum)核型公式为6n=6x=54=36m+11sm+4T+2M+1 st,2B,核型不对称系数为60.33%。

The root tips of 7 wild species of Chrysanthemum and related genera were pretreated with 8- hydroxyquinoline and ice-water mixture and the time gradient of dissociation was set to obtain the optimal dissociation time of each wild species. The results showed that the pretreatment of those species with ice-water mixture for 24 h could gain a high-quality chromosome sectioning with well dispersion, normal form and easy statistic analysis, and the most favorable dissociation times for Ajania fruticulosa, Chrysanthemum lavandulifolium, Opisthopappus taihangensis, Chrysanthemum indicum var. aromaticum, Chrysanthemum indicum,Chrysanthemum chanetii and Chrysanthemum vestitum were 12.5 min, 12 min, 12 min,ll min,ll min, 11 min and 14 min respectively. The obtained karyotype formulae of those species were as follows. Ajania fruticulosa：2n = 2x = 18 = 16m ＋ 2sm, 1B, and a asymmetry coefficient of 57. 26%; Chrysanthemum lavandulifolium：2n = 2x = 18 = 17m ＋ M, 1A, and a asymmetry coefficient of 53. 71%; Opisthopappus taihangensis：2n = 2x = 17 = 14m ＋ 2M ＋ sin, 1A, and a asymmetry coefficient of 54.95% ; Chrysanthemum indicum var. aromaticum： 2n = 2x = 18 = 15m ＋ 2sm ＋ M, 2A, and a asymmetry coefficient of 56. 86% ; Chrysanthemum indicum： 4n = 4x = 36 = 31m ＋ 3sm ＋ 2M, 2B, and a asymmetry coefficient of 56. 28% ; Chrysanthemum chanetii：4n = 4x = 36 = 25m ＋ 8sm ＋ 2T ＋ M, 2B, and a asymmetry coefficient of 58.95% ;Chrysanthemum vestitum： 6n = 6x = 54 = 36m ＋ 11 sm ＋ 4T ＋ 2M ＋ 1st, 2B, and a asymmetry coefficient of 60.33%.