摘要
【目的】竹类植物种类繁多,不同类型竹种染色体数目差异较大,本研究旨在揭示不同竹种染色体核型特征及其基因组大小信息,进而从核型进化角度判断不同竹种的进化顺序,分析不同竹种基因组大小与其染色体数目之间的关系。【方法】以散生竹种雷竹、黄杆乌哺鸡竹,混生竹种日本矮竹及丛生竹种鱼肚腩竹为研究材料,采用传统压片技术对这4个竹种的核型特征进行研究,同时利用流式细胞仪测定这些竹种的基因组大小。【结果】1）4种竹子的核型参数分别为：雷竹核型公式为2n=48=40m＋6sm＋2st,染色体相对长度变化范围为2.464%-6.269%,臂比大于2的染色体比例为12.50%,最长染色体与最短染色体之比为2.554,核型不对称系数为60.107,核型分类属于2B类型;黄杆乌哺鸡竹的核型公式为2n=48=24m＋16sm＋8st,染色体相对长度变化范围为2.185%-9.091%,臂比大于2的染色体比例为29.17%,最长染色体与最短染色体之比为4.161,核型不对称系数为64.49,核型分类属于2C类型;日本矮竹的核型公式为2n=48=28m＋18sm＋2st,染色体相对长度变化范围为2.080%-7.881%,臂比大于2的染色体比例为20.83%,最长染色体与最短染色体之比为3.789,核型不对称系数为61.505,核型分类属于2B类型;鱼肚腩竹核型公式为2n=69=40m＋25sm＋4st,染色体相对长度变化范围为1.790%-4.382%,臂比大于2的染色体比例为28.57%,最长染色体与最短染色体之比为2.448,核型不对称系数为64.076,核型分类属于2B类型。2）雷竹、黄杆乌哺鸡竹、日本矮竹及鱼肚腩竹的2C DNA含量分别为（3.71±0.10）pg,（3.93±0.85）pg,（4.67±0.52）pg和（2.92±0.38）pg。【结论】根据核型不对称系数等指标判断,4个竹种的进化程度从原始到进化依次为雷竹、日本矮竹、鱼肚腩竹、黄杆乌哺鸡竹;在基因组大小方面,4个竹种中,丛生竹种鱼肚腩竹染色体数目最多,但是其2C DNA含量却是4个竹种中最小的,混生竹种日本矮竹2C DNA含量是4个竹种中最大的,所测竹种的基因组大小与其染色体数目并不是成正相关的关系。
【Objective】There are many bamboo species with different chromosome numbers. The study was aimed to analyze the karyotype characteristics and genome sizes of different bamboo species,to estimate their evolutionary order according to the karyotype information,and to reveal the relationship between the genome size and chromosome numbers.【Method】Traditional squash technique and flow cytometry were used to study the karyotype and genome size of the four bamboo species, i. e. the monopodial bamboo species of Phyllostachys praecox cv. Prevernalis and P. vivax f.aureocaulis,mixed monopodial and sympodial bamboo species Sasa pygmea,and sympodial bamboo species Bambusa gibboides. 【Result】The karyotype parameters of these four bamboos were as follows： The karyotype formula of P. praecox cv. Prevernalis was 2n = 48 = 40 m ＋ 6sm ＋ 2st,and the range of relative chromosome length was from 2. 464% to6. 269%,the proportion of chromosomes whose arm ratio larger than 2 was 12. 5%,the ratio of chromosome length（ Longest /Shortest） and the karyotype asymmetry index were 2. 554 and 60. 107,respectively. The karyotype was 2B type. As for P. vivax f. aureocaulis,its karyotype formula was 2n = 48 = 24 m ＋ 16 sm ＋ 8st,the range of relative chromosome length was from 2. 185% to 9. 091%,the proportion of chromosomes whose arm ratio larger than 2 was29. 17%,the ratio of chromosome length（ Longest / Shortest） and asymmetry index were 4. 161 and 64. 49,respectively.Its karyotype belonged to 2C type. The karyotype formula of S. pygmea was 2n = 48 = 28 m ＋ 18 sm ＋ 2st,the range of relative chromosome length was from 2. 080% to 7. 881%,the proportion of chromosomes whose arm ratio larger than 2was 20. 83%, the ratio of chromosome length（ Longest / Shortest） and asymmetry index were 3. 789 and 61. 505,respectively. Its karyotype belonged to 2B type. However,the karyotype formula of B. gibboides was different from the above three bamboo species,its karyotype formula was 2n = 69 = 40 m ＋ 25 sm ＋ 4st,and the range of relative chromosome length was from 1. 790% to 4. 382%,the proportion of chromosomes whose arm ratio larger than 2 was 28. 57%,the ratio of chromosome length（ Longest / Shortest） and asymmetry index were 2. 448 and 64. 076,respectively. Its karyotype belonged to 2B type. The genome sizes of P. praecox cv. Prevernalis,P. vivax f. aureocaulis,S. pygmea,and B.gibboides were（ 3. 71 ± 0. 10） pg,（ 3. 93 ± 0. 85） pg,（ 4. 67 ± 0. 52） pg and（ 2. 92 ± 0. 38） pg,respectively.【Conclusion】The evolutionary order of these four bamboo species was probably P. praecox cv. Prevernalis,S. pygmea,B. gibboides,and P. vivax f. aureocaulis. The genome size of S. pygmea was the largest among these four different bamboo species. However,the genome size of B. gibboides was the smallest although its chromosome number was the largest among these bamboos. The genome size did not positively correlate with the chromosome number of these bamboos.
出处
《林业科学》
EI
CAS
CSCD
北大核心
2016年第9期57-66,共10页
Scientia Silvae Sinicae
基金
浙江省自然科学基金项目(LY13C160011)
浙江省教育厅高等学校访问学者专业发展项目(FX2013055)
浙江自然科学基金杰出青年项目(LR12C16001)
国家自然科学基金项目(30901155)
