The RAPD technique has been successfully used in a variety of taxonomic and genetic diversity studies. The genetic diversity of 19 accessions of Salvadora oleoides collected from different regions of North-West India has been reported in this paper using 16 RAPD primers. 164 bands were scored corresponding to an average of 10.25 bands per primer with 146 bands showing polymorphism (90.09%). Jaccard similarity coefficient ranged from 0.21 to 0.94. A dendrogram constructed based on the UPGMA clustering method revealed two major clusters CL1 and CL2. The dendrogram has put all the genotypes in two clusters CL2 comprises of two accessions (Jalore & Jhunjhunu) while CL1 is further divided into two groups (1 & 2). The group 1 comprises 4 accessions (Rohtak, Hisar, Rewari, M. Garh) while group 2 is further divided in two sub groups (SG1 & SG2) out of which SG1 comprises 6 accessions while SG2 comprises 7 accessions. The study revealed rich genetic diversity among S. oleoides of North-West India.
Background: Rainfed lowland rice genotypes are often defined ambiguously for its historic lack of attention from the rice researchers. With little scope for expansion of the irrigated rice lands, it is necessary to exploit the diversity of the rainfed lowland and deep water rice genotypes to improve the productivity and to develop new cultivars showing tolerance to submergence and other abiotic stresses.
Results: Genetic variation of 21 lowland rice cultivars and 3 shallow water rice cultivars were investigated at the DNA level using SSR marker method using PCR. 45 SSR markers were used to amplify DNA fragments and 146 PCR products were obtained. The result of PAGE electrophoretic analysis confirmed 131 bands (89.72%) to be polymorphic. All the 45 primers amplified generating two to eight major bands. Polymorphism information content ranged from 0.041 to 0.728. Two primers showed monomorphism. Cluster analysis grouped the rice genotypes into 5 classes. In general, higher polymorphism was found between rainfed lowland and deepwater varieties. A dendrogram that shows the genetic distance of 24 rice cultivars was constructed based on their DNA polymorphisms.
Conclusion: This diversity analysis of lowland rice analysis was found to be better and more accurate than the previous classification made by RAPD and other SSRs. This micro satellite information can be efficiently used to assess the diversity of various rice genotypes that are potentially useful in further breeding programs and can act as a landmark for variety registration authority.
Genetic variability of the Vitex negundo L. using molecular markers was studied using RAPD as a backend tool. The map is defined by 10 randomly amplified polymorphic DNA (RAPD) markers of which 5 molecular markers represent the amplification of the genes. The plant V. negundo L. is known for its antibacterial, antitumor, astringent, expectorant, febrifuge, sedative, tonic and vermifuge values. The dendrogram was constructed from the RAPD bands were interpreted using the POPGENE software system. Our results showed that RAPD markers could be used to gain rapid and precise information about genetic similarities or dissimilarities in wild systems that might not be so easily evident from other commonly used techniques.