RAPD Fingerprinting and Genetic Relationships of Some Wheat Genotypes
Issue:
Volume 7, Issue 1, March 2019
Pages:
1-11
Received:
14 December 2018
Accepted:
15 January 2019
Published:
4 February 2019
Abstract: The genetic variability and relationships among 5 Egyptian wheat genotypes representing Sakha8, Sakha69, Sakha93, Sids1 and Gemmiza7 were analyzed using 8 random amplified polymorphic DNA (RAPD). A total of 77 loci (73 % polymorphic) in all 5 wheat genotypes was amplified and discriminated all the wheat genotypes. PIC, RP, MI, DP values were evaluated and revealed degree of genetic divergence among the cultivars used. A cluster based on UPGMA (Un-weighted Pair-Group Method with Arithmetic Mean) analysis was used to determine genetic similarities. The five wheat genotypes were divided into two main clusters. Cluster 1 was divided into two groups. In subgroup 1 were included genotype 1 and genotype 2. They seemed very close which might depict sharing of the genetic background among the genotypes. In consequence, the close genetic relationships are entirely alarming and may hinder further plant improvement. Genotype 5 was in subgroup 2. The second cluster was included genotype 3 and genotype 4. The same genotypes were also assessed in field conditions for structural analyses, which were carried out based on six yield components. The dendrogram created was comparatively analyzed with the RAPD dendrogram. This study additionally indicates that RAPD markers are useful for distinguishing and characterizing wheat cultivars. The genetic relatedness among these genotypes could provide useful information for conservation and selection of cross parents in breeding.
Abstract: The genetic variability and relationships among 5 Egyptian wheat genotypes representing Sakha8, Sakha69, Sakha93, Sids1 and Gemmiza7 were analyzed using 8 random amplified polymorphic DNA (RAPD). A total of 77 loci (73 % polymorphic) in all 5 wheat genotypes was amplified and discriminated all the wheat genotypes. PIC, RP, MI, DP values were evalua...
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Genetic Diversity of Groundnut Rosette Disease Causal Agents Towards Its Management: A Review
Benard Mukoye,
Anthony Simiyu Mabele
Issue:
Volume 7, Issue 1, March 2019
Pages:
12-17
Received:
7 March 2019
Accepted:
16 April 2019
Published:
3 June 2019
Abstract: In this review, the genetic diversity of the three causal agents of Groundnut Rosette Disease (GRD) in Sub-Saharan Africa (SSA) are discussed. Epidemics of GRD viruses in SSA, often reduce groundnut productivity. The etiology of GRD is a complex, involving three agents; Groundnut rosette assistor luteovirus (GRAV), Groundnut rosette umbravirus (GRV) and a Satellite-RNA (Sat-RNA) of GRV. The complex etiology and lack of sensitive and specific diagnostic tools, are major limitations in understanding the epidemiology of GRD viruses, and developing appropriate management strategies for the disease. Nucleotide identity of 97 to 100% among GRAV isolates from different regions in Kenya have been reported. Sat-RNA sequences from Kenya shared nucleotide identity of 95% with Malawian isolate (M24S) and 89% with Nigerian isolate (NG3a). GRAV CP gene was highly conserved (97-99%) regardless of the geographical distance. However, for GRV and Sat-RNA diversity increased with increase in geographical distance. In addition, phylogenetic analysis showed that isolates of GRV (ORF3 and 4) and Sat-RNA clustered together depending on the country of origin. Recent study has unveiled a chlorotic variant of Sat-RNA in Kenya with 97% sequence identity to the Malawian chlorotic isolate (M24S). Pathogen derived resistance (PDR) suitable for each diverse regions where the disease occurs is a promising management strategy which mainly depends in studies to deeply understand the genetic diversity of the three GRD causal agents. Currently, GRAV-CP is the best candidate for PDR.
Abstract: In this review, the genetic diversity of the three causal agents of Groundnut Rosette Disease (GRD) in Sub-Saharan Africa (SSA) are discussed. Epidemics of GRD viruses in SSA, often reduce groundnut productivity. The etiology of GRD is a complex, involving three agents; Groundnut rosette assistor luteovirus (GRAV), Groundnut rosette umbravirus (GRV...
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