Abstract

Morphological and molecular markers are useful in genetic diversity assessment and improvement of plants. In the present study, five morphological traits, random amplified polymorphic DNA (RAPD) and Start codon targeted (SCoT) markers were used for genetic diversity evaluation of Sewan grass (Lasiurus sindicus Henr.), a valuable endemic plant of Indian Thar desert.

Accessions collected from 14 different sites were used for measuring morphological traits, namely plant height (PH), number of tillers (NT), number of nodes (NN), leaf length (LL) and spike length (SL) which showed large variations among populations; particularly PH, NT and LL. Ward’s linkage hierarchical cluster analysis exhibited two major clusters and Cluster I contained two minor clusters.

The percentage polymorphic bands (PPB) produced were 89.64% and 64.51% for RAPD and SCoT respectively. RAPD markers based dendrogram revealed three clades while there was no clear clade formation with SCoT markers. Single primer amplification reaction (SPAR) analysis with combined data of RAPD + SCoT showed more similarity with SCoT than with RAPD clusters. AMOVA revealed higher variation within population (90%) than among populations (10%) of L. sindicus. The Principal coordinate analysis (PCoA) also supported this result.

There was no correlation between morphological and molecular data confirming environmental impact on morphological variation. SCoT and SPAR markers have clearly identified a novel genotype (LS JS 3) which has high values of PH, NN and LL. This study suggests that morphological data combined with molecular data can alone help in the identification of novel genotypes of L. sindicus among its populations.

摘要

形态和分子标记可用于植物的遗传多样性评估和改良。本研究利用随机扩增多态性DNA（RAPD）和起始密码子靶向（SCoT）标记5个形态性状对印度塔尔沙漠特有植物西旺草（Lasiurus sindicus Henr.）进行遗传多样性评价。

从 14 个不同地点收集的材料用于测量形态性状，即株高 (PH)、分蘖数 (NT)、节数 (NN)、叶长 (LL) 和穗长 (SL)人口；特别是 PH、NT 和 LL。Ward 的连锁层次聚类分析展示了两个主要聚类，聚类 I 包含两个次要聚类。

RAPD 和 SCoT 产生的多态带百分比 (PPB) 分别为 89.64% 和 64.51%。基于 RAPD 标记的树状图显示了三个进化枝，而 SCoT 标记没有明确的进化枝形成。结合 RAPD + SCoT 数据的单引物扩增反应 (SPAR) 分析显示，与 RAPD 簇相比，SCoT 与单引物扩增反应 (SPAR) 的相似性更高。AMOVA 揭示了L. sindicus种群内 (90%) 的变异性高于种群间 (10%) 。主坐标分析 (PCoA) 也支持这一结果。

形态和分子数据之间没有相关性，证实了环境对形态变异的影响。SCoT 和 SPAR 标记已清楚地识别出具有高 PH、NN 和 LL 值的新型基因型 (LS JS 3)。这项研究表明，形态学数据与分子数据相结合可以单独帮助在其种群中鉴定L. sindicus的新基因型。