Claid Mujaju - Academia.edu (original) (raw)

Papers by Claid Mujaju

American Journal of Plant Sciences

Watermelon research in Southern Africa, has predominantly observed the clear existence of the swe... more Watermelon research in Southern Africa, has predominantly observed the clear existence of the sweet watermelon and cow melon forms of watermelon, cultivated on farm and even some occurring in the wild. Molecular characterization of 48 watermelon accessions collected from National Genebank of Zimbabwe using 9 SSR markers generated a total of 49 putative alleles. The average number of alleles detected by each primer was 5.4. Analysis of molecular variance within and among accessions of watermelons revealed that only 39% of the total variation resides between these two groups (cow-melons and sweet watermelons), 24% between accession within groups and 37% within accessions. Multivariate analyses employed provide evidence of the existence of introgression between sweet water melons and cow melons, as reflected by some accessions of cow melons, clustering into a hybridogenous group. Most of watermelon accessions within the hybridogenous group [A (II)] were collected from drier communal areas, while those accessions within the cow melon group [A (I)] are mostly from research centers. The separation of cow melons into distinct groups could be indicative of a possible formation of an isolated evolutionary unit.

Agriculture & Food Security

International Journal of Biodiversity, 2015

The aim of this study was to apply some of the vegetative and fruit traits which are easily recog... more The aim of this study was to apply some of the vegetative and fruit traits which are easily recognised to identify the variation and the diversity level of the most famous Sudanese date palm cultivars grown on farm in the northern region of Sudan. Sixteen phenotypic traits consisting of ten quantitative and six qualitative characteristics were used for describing the vegetative and fruit characteristics. The principal components analysis (PCA) and UPGMA clustering were used to analyse the data set. The results revealed high variability among the cultivars according to PCA. Fourteen out of the sixteen quantitative and qualitative traits investigated showed a strong discriminating factor suggesting their possible uses in the initiation of Sudanese date palm morphological descriptor list. UPGMA clustering exhibited strong relationship between some cultivars according to their fruit and vegetative characteristics similarity. Based on morphological traits, cultivars Wad-laggi (Lag) and W...

Australian Journal of Crop Science, 2012

Traditional farming systems have been associated with the occurrence of intervarietal and intersp... more Traditional farming systems have been associated with the occurrence of intervarietal and interspecific natural crosses in many crop plants, thus contributing to the genetic diversity of the crop through genetic exchange. In this study, a combination of farmerpreferred morphological traits and RAPD markers were used to evaluate the dynamics of genetic diversity in 43 watermelon accessions collected at a single village level with a traditional farming system. The molecular variability assessed with RAPD markers and analyzed with multidimensional scaling and cluster analysis, demonstrated a substantial differentiation among the accessions. Population structure analysis also demonstrated the existence of three major forms of watermelon, identified by a set of alleles predominant within each form. Dendrograms based on RAPD data and on farmer-preferred traits data were positively correlated according to a Mantel test. Although cultivated cow-melons were genetically most similar to wild-weedy plants at molecular level, they grouped more similar to sweet watermelons based on farmer-preferred traits. The present study revealed limited gene flow between three forms of watermelon and provides insight into how the genetic differentiation corresponds to farmers' classification of watermelons.

International Journal of Biodiversity and Conservation, Sep 30, 2011

Identification of potential areas and regions for collection of watermelon germplasm is pivotal f... more Identification of potential areas and regions for collection of watermelon germplasm is pivotal for better utilization of the available diversity. DIVA-GIS were used on all watermelon collections in the National Genebank of Zimbabwe to explore the pattern of distribution of two forms of watermelons; sweet watermelon (Citrullus lanatus var. lanatus) and cow-melon (Citrullus lanatus var. citroides). DIVA-GIS analysis revealed that most watermelon accessions have been collected at altitudes ranging from 160 to 1550 m above sea level, and that sandy loam and sand soils apparently are preferred. Distribution of the two forms of watermelons across soil types, altitudinal ranges and provinces is similar. In order to maintain watermelon diversity, promotion of in-situ or on-farm conservation of watermelon genetic resources using best practices in traditional farming system is recommended. Furthermore, this should be complemented by ex-situ conservation through gap collection missions in order to identify and document additional diversity hotspots.

The genus Citrullus, belongs to the Cucurbitaceae family. Among the four species in this genus, a... more The genus Citrullus, belongs to the Cucurbitaceae family. Among the four species in this genus, a single species Citrullus lanatus (Thunberg) Matsum. & Nakai, commonly known as watermelon, is grown throughout the drought-prone southern Africa as a staple food (edible seeds), a dessert food (edible flesh), and for animal feed. The fruit can be eaten fresh or cooked and the seeds can be roasted. Its uses are however, multifaceted and vary depending on the customs of the humans growing this crop. In addition, the fruit can serve as a source of water, especially in deserts or where drinking water is contaminated. Several morphotypes of watermelon are found in southern Africa. Citrullus lanatus exhibits expansive polymorphism in southern Africa and the species occurs in the following forms: wild populations distributed throughout the country in a wide range of habitat types; sweet watermelon, cooking melon and seed melon landraces of the traditional agrosystems; and possibly introgressed types which are regarded as agronomic weeds. Farmers" traditional onfarm practices contribute to the maintenance of watermelon landraces, and therefore play a role in nurturing local-level diversity. The wild watermelon is widely distributed in Africa and Asia, but originates from southern Africa occurring naturally in

Genetic Resources and Crop Evolution, 2015

AFRICAN JOURNAL OF AGRICULTURAL RESEEARCH, 2011

Watermelon landraces provide valuable food for human consumption as well as animal feed in the dr... more Watermelon landraces provide valuable food for human consumption as well as animal feed in the drought-prone parts of Zimbabwe, especially in the Masvingo area where subsistence agriculture is predominant. Using random amplified polymorphic DNA (RAPD), this study investigated intra-and inter-landrace genetic variation at the village level. Seedling offspring from 29 landraces, collected at four recently established farms in the same village, were assessed; 20 landraces of sweet watermelon and 9 landraces of cow-melon. Analysis of Molecular Variance (AMOVA) and ordination revealed much variation across the landraces, and strong differentiation between the two main forms of sweet watermelons and cow-melons. Within each of these two forms, landraces from the same farm formed well-separated sub-clusters. The farmers' perceptions with regards to culture, cropping systems, seed systems and utilization were also documented. Obtained information about, e.g., farmers' use of own seed or seed acquired from close family members, traditional myths and different cultivation practices, are concordant with the results from the RAPD analysis. This study is relevant for the development of in situ management strategies for conservation of watermelon landraces at the village level.

American Journal of Plant Sciences, 2013

Fifteen expressed sequence tag (EST)-derived simple sequence repeats (EST-SSRs) were used to inve... more Fifteen expressed sequence tag (EST)-derived simple sequence repeats (EST-SSRs) were used to investigate genetic diversity in 139 plants obtained from seeds of 35 watermelon accessions collected from all the geographical provinces of Zimbabwe. In addition, 15 plants representing three commercial varieties developed in the United States (USA) were analyzed for comparison. A total of 65 alleles were detected among all the watermelon accessions. For the 13 polymorphic EST-SSR loci, number of alleles per locus varied from 2 to 13, with an average of 5 alleles per locus. Values for the polymorphic information content increased as the number of alleles increased, and varied from 0.15 to 0.77 with an average of 0.54 suggesting sufficient discriminatory power. Both cluster analysis and principal coordinate analysis (PCA) produced two major clusters; one with the 22 cow-melon accessions and the other with the 16 sweet watermelon accessions. Within the sweet watermelon group, two distinct sub-clusters formed, one of which contained only two of the commercial varieties from USA. Partitioning of genetic variation in the Zimbabwean material using analysis of molecular variation (AMOVA) revealed that 64% of the total variation resides between the two major forms, i.e. sweet watermelons and cow-melons, 28% between accessions within forms and 8% within accessions. The EST-SSR markers revealed a somewhat higher diversity in sweet watermelon accessions compared to that of cow-melons. This finding is contrary to previous reports using other markers (genomic SSR loci or RAPD) and/or a plant material that is likely to have experienced more stringent selection procedures compared to the landraces analyzed in our study.

Scientia Horticulturae, 2013

ABSTRACT A set of 85 heirloom apple cultivars aimed for long-term preservation in two germplasm c... more ABSTRACT A set of 85 heirloom apple cultivars aimed for long-term preservation in two germplasm collections in Sweden and Finland was evaluated with 8 SSR primer pairs to evaluate genetic diversity and genetic relatedness. An additional set of 16 European cultivars was included for comparison. The eight SSR primer pairs amplified 9 loci and 105 alleles. Genetic analyses performed by MDS indicated some differentiation between Swedish and Finnish cultivars, with European cultivars intermixed with the Swedish. The existence of three groups was, however, indicated by a Bayesian model-based clustering. One of the groups was clearly dominated by Swedish cultivars and another by Finnish. The third group included almost equal proportions of representatives from all three areas. The obtained results confirmed the genetic distinctness of Finnish apple cultivars, which can be explained by climate adaptation and admixture with a Russian gene pool.

International Journal of Botany, 2008

Hereditas, 2010

Low polymorphism in cultivated watermelon has been reported in previous studies, based mainly on ... more Low polymorphism in cultivated watermelon has been reported in previous studies, based mainly on US Plant Introductions and watermelon cultivars, most of which were linked to breeding programmes associated with disease resistance. Since germplasm sampled in a putative centre of origin in southern Africa may harbour considerably higher variability, DNA marker-based diversity was estimated among 81 seedlings from eight accessions of watermelon collected in Zimbabwe; fi ve accessions of cow-melons (Citrullus lanatus var. citroides) and three of sweet watermelons (C. lanatus var. lanatus). Two molecular marker methods were used, random amplifi ed polymorphic DNA (RAPD) and simple sequence repeats (SSR) also known as microsatellite DNA. Ten RAPD primers produced 138 markers of which 122 were polymorphic. Nine SSR primer pairs detected a total of 43 alleles with an average of 4.8 alleles per locus. The polymorphic information content (PIC) ranged from 0.47 to 0.77 for the RAPD primers and from 0.39 to 0.97 for the SSR loci. Similarity matrices obtained with SSR and RAPD, respectively, were highly correlated but only RAPD was able to provide each sample with an individual-specifi c DNA profi le. Dendrograms and multidimensional scaling (MDS) produced two major clusters; one with the fi ve cow-melon accessions and the other with the three sweet watermelon accessions. One of the most variable cow-melon accessions took an intermediate position in the MDS analysis, indicating the occurrence of gene fl ow between the two subspecies. Analysis of molecular variation (AMOVA) attributed most of the variability to within-accessions, and contrary to previous reports, sweet watermelon accessions apparently contain diversity of the same magnitude as the cow-melons.