Anjali N, Ganga K M, Nadiya F, Shefeek S, Sabu K K
Biotechnology and Bioinformatics Division, Jawaharlal Nehru Tropical Botanic Garden and Research Institute (JNTBGRI), Palode, Thiruvananthapuram, 695562 India.
Springerplus. 2016 Sep 13;5(1):1560. doi: 10.1186/s40064-016-3226-x. eCollection 2016.
The main goal of the work was to analyse intraspecific variation in Elettaria cardamomum Maton (cardamom) using genome size, cytological studies and molecular marker data. Nuclear DNA content and molecular marker details furnish data on genome size and genetic diversity respectively among the studied accessions and both complement each other for evolutionary and taxonomic studies.
The relative 2C genome size and total number of base pairs of cardamom was determined through flow cytometric analysis using propidium iodide staining. The nuclear DNA content was estimated in various sections of the species representing individuals from wild and cultivar genotypes following Zea mays L. CE-777 (2C = 5.43 pg) as internal reference standard. Chromosome number from growing root tip was examined following standard protocols. Twenty-six ISSR primers that generated polymorphic bands were used for genetic diversity analysis of the thirty accessions of cardamom. Estimated nuclear 2C DNA content ranged from 2.57 to 3.22 pg demonstrating 1.25-fold variation. The mean amount of 2C nuclear DNA of the cardamom was calculated as 2.87 pg which is equivalent of 2806 Mbp as the diploid genome size. The chromosome number was found to be 2n = 48. Among the thirty accessions of cardamom studied using ISSR markers, C53 (feral from Bonacaud) showed a very prominent level of genetic diversity and was lowest for C96 (Avinash-I, a released variety from Indian Institute of Spices Research, Kozhikode).
These analyses revealed the existence of genetic variability within the studied cardamom accessions. The plant specimens also differed significantly in their genome size. However, the genetic variability parameters did not show any correlation with genome size.
本研究的主要目的是利用基因组大小、细胞学研究和分子标记数据，分析小豆蔻（Elettaria cardamomum Maton）的种内变异。核DNA含量和分子标记细节分别提供了所研究种质间的基因组大小和遗传多样性数据，两者在进化和分类学研究中相互补充。
通过碘化丙啶染色的流式细胞术分析，确定了小豆蔻的相对2C基因组大小和碱基对总数。以玉米（Zea mays L.）CE - 777（2C = 5.43 pg）作为内部参考标准，估计了该物种不同部分代表野生和栽培基因型个体的核DNA含量。按照标准方案检查生长根尖的染色体数目。使用26条产生多态性条带的ISSR引物，对30份小豆蔻种质进行遗传多样性分析。估计的核2C DNA含量范围为2.57至3.22 pg，显示出1.25倍的变异。小豆蔻的2C核DNA平均含量计算为2.87 pg，相当于二倍体基因组大小为2806 Mbp。发现染色体数目为2n = 48。在使用ISSR标记研究的30份小豆蔻种质中，C53（来自博纳考德的野生种）显示出非常显著的遗传多样性水平，而C96（阿维纳什 - I，印度香料研究所科泽科德发布的品种）的遗传多样性水平最低。
这些分析揭示了所研究的小豆蔻种质中存在遗传变异性。植物标本在基因组大小上也存在显著差异。然而，遗传变异性参数与基因组大小没有显示出任何相关性。
