基于RAPD-PCR标记的印度亚麻品种遗传多样性和指纹图谱分析(英文)

Genetic diversity and fingerprinting of flax cultivars of Indiausing RAPD-PCR markers

栽培的亚麻(L.usitatissimum)通常为亚麻籽,以其油分和纤维而被认为是具有较高经济价值的作物之一。开发亚麻遗传资源并进一步进行遗传改良,须了解其遗传变异的范围和结构。位于坎普尔的C.S.农业科技大学种质管理单位保存有广泛收集而来的2772份栽培和野生亚麻资源。从中选出23份不同基因型栽培亚麻品种包括5份两用品种、4份种用品种、14份具有不同形态和经济特性的引进种用品种以及1份野生品系(L.grandiflorum),采用RAPD标记进行遗传多样性分析。20条随机引物共产生242条带,每条引物扩增带数为1～20条,平均为10.95条。所有基因型和位点的RAPD多态性比例为90.49%。DICE系数相似矩阵分析揭示其遗传相似性为0.63～0.97,平均相似系数为82%,说明这些亚麻品种(系)的遗传背景较窄。采用UPGMA法以及NTSYS-pc软件的SAHN聚类分析模型对遗传相似矩阵进行聚类分析,发现属于L.uitatisimums的所有栽培品种在X轴上可聚为一类,而L.grandiflorum野生种单独在Y轴上聚为一类。主成分分析结果表明,除了Shekha(r优良种用品种)和野生种L.grandiflorum广泛分布外,其他所有种用品种、两用品种和外来品种聚类很近。由于亚麻栽培品种的遗传关系相近,须对亚麻种质的各种基因型进行鉴定,以拓宽今后育种计划中的遗传基础。

Cultivated flax （L. usitatissimum） commonly known as linseed, is one of the high economic value crops in terms of oil and fibre. Knowledge of the range and structure of the genetic variability is essential in exploitation of flax genetic resources for further genetic improvement. The germplasm management unit at C. S. University of Agriculture and Technology, Kanpur maintains a wide collection of cultivated and wild flax consisting of 2772 accessions. Out of these, twenty-three genotypes of cultivated flax cultivars including five dual purpose cultivars, four seed cultivars and fourteen exotic seed cuhivars having different morpho-economic traits and one wild species L. grandiflorum were chosen for genetic diversity analysis using RAPD markers. Two hundred and forty-two RAPD bands were generated by 20 random primers. Number of bands amplified for each primer ranged from 1 to 20 with an average of 10.95 bands per primer. The percent polymorphism of RAPD bands over all genotypes and loci was 90.49%. A similarity matrix generated through DICE coefficient revealed genetic similarity ranging from 0.63 to 0.97. Mean similarity coefficient of 82% among all the genotypes indicated the narrow genetic base within these linseed cultivars. The genetic similarity matrix was used to perform cluster analysis using the UPGMA （Unweighted Pair Group Method with Arithmetic Mean Clustering） method following the SAHN cluster analysis module of NTSYS-pc. All the cuhivars belonging to L usitatissimum were clustered in one group at X-axis, whereas L. granditlorum was separated at Y-axis. Results based on the principle component analysis revealed that all the seed purpose, dual purpose and exotic cultivars of flax were closely clustered except Shekhar （a superior seed cultivar） and L. granditlorum （a wild species） were widely scattered. The close genetic relatedness of cultivated flax cultivars necessitate identification of diverse genotypes from germplasm for broadening the genetic base for future breeding programs.