Optimization of ISSR marker for African edible-seeded Cucurbitaceae species’ genetic diversity analysis

We applied a molecular approach using inter-simple sequence repeat (ISSR) markers on three African edible-seeded cucurbits (Citrullus lanatus L. Matsumura and Nakai, Cucumeropsis mannii L. Naudin and Cucumis melo var. agrestis L. Naudin). To obtain clear and reproducible bands on 1.5% agarose gels, we screened 21 ISSR primers and three parameters (annealing temperature, gel tray, and voltage and running time). The resolution of 11 ISSR markers was performed, with optimal annealing temperature (Ta) varying from 50 to 52°C. The best combination to obtain clear and well-distinguished band patterns was 1.5% agarose gel with a 20-lanes tray (6 mm width) at 80 V for 5 h. Applying the 11 ISSR primers on DNA extracted from an accession of C. lanatus, 66 bands with 4 to 11 bands per primer was observed.Keywords: ISSR, Cucurbits, genetic diversity, molecular markers, optimizatio

Macronutrient composition of three cucurbit species cultivated for seed consumption in Côte d’Ivoire

Dry seeds from three indigenous cucurbits [Citrullus lanatus var. citroides (Thumb.) Matsum. & Nakai.,Cucumeropsis mannii Naudin, and Cucumis melo var. agrestis L.] largely cultivated in Côte d’Ivoire andconsumed as sauce thickeners were analyzed for their proximate composition and compared to a locallandrace of peanut (Arachis hypogae L.). The protein contents were 29.23±1.74, 36±2.17, 29.55±2.09, and24.79±0.44% for C. lanatus, C. mannii, C. melo, and A. hypogaea, respectively. The highest estimates offat content was observed with C. lanatus (56.67±4.90%) followed in decreased order by the peanut(48.17±1.60%), C. mannii (45.89±4.73%), and C. melo (42.67±3.43%). The carbohydrate content for C.lanatus was 9.87±3.52% and C. mannii and C. melo had 13.86±3.64 and 23.18±4.80%, respectively. C.melo was then the highest in carbohydrate content whereas A. hypogaea has the lowest value(6.39±2.66%). The crude fibre contents for C. lanatus, C. mannii, and C. melo averaged 2.87±1.07,2.30±0.85, and 2.94±0.75%, respectively. The three cucurbit species were markedly low in fibre value,compared to the analyzed peanut (17.14±3.82%). As expected on the basis of several published data,ash content of seeds from indigenous cucurbits was generally low: 1.33±0.52% (C. lanatus), 2.50±1.38%(C. mannii), and 1.67±0.82% (C. melo)

Genetic Diversity of Andean Tuber Crop Species in the in situ Microcenter of Huanuco, Peru

peer reviewedAndean tuber crop species oca (Oxalis tuberosa Molina), ulluco (Ullucus tuberosus Caldas), and mashua (Tropaeolum tuberosum Ruiz & Pav.) play major roles in Andean communities. These species show high variability but are threatened with genetic erosion. To study the management of genetic resources of neglected vegetatively propagated crop species, we studied genetic diversity and structure of these species in an in situ diversity microcenter (Huanuco, Peru). A sample of 15 varieties of oca, 15 of ulluco, and 26 of mashua was analyzed with the inter simple sequence repeats (ISSR) molecular markers. Mean genetic distances and global genetic diversities were high for the three species, with higher values for mashua than for oca and ulluco. Assignment technique divided both oca and ulluco samples into two genetic clusters; the mashua sample probably belongs to a single genetic cluster. Inter simple sequence repeats (ISSR) technique showed intravarietal genetic variability for most varieties, suggesting an underestimation of the in situ genetic variability. These results are discussed considering how variation in breeding systems and farmers' practice influenced patterns of genetic diversity. Our findings confirm the hypothesis of a considerable amount of variability found in neglected Andean tubers and are essential to deserve adequate conservation strategies and to maintain genetic resources of neglected Andean tuber crop species under a threat of genetic erosion

Full Length Research Paper - Optimization of ISSR marker for African edible-seeded Cucurbitaceae species’ genetic diversity analysis

We applied a molecular approach using inter-simple sequence repeat (ISSR) markers on three African edible-seeded cucurbits (Citrullus lanatus L. Matsumura and Nakai, Cucumeropsis mannii L. Naudin and Cucumis melo var. agrestis L. Naudin). To obtain clear and reproducible bands on 1.5% agarose gels, we screened 21 ISSR primers and three parameters (annealing temperature, gel tray, and voltage and running time). The resolution of 11 ISSR markers was performed, with optimal annealing temperature (Ta) varying from 50 to 52°C. The best combination to obtain clear and well-distinguished band patterns was 1.5% agarose gel with a 20-lanes tray (6 mm width) at 80 V for 5 h. Applying the 11 ISSR primers on DNA extracted from an accession of C. lanatus, 66 bands with 4 to 11 bands per primer was observed

Morphological and allozyme variation in a collection of Lagenaria siceraria (Molina) Standl. from Côte d'Ivoire

This study describes the intraspecific variation of 30 edible-seed Lagenaria siceraria germplasm accessions from the University of Abobo-Adjamé. These accessions were collected from three (Centre, East and South) geographical zones of Côte d’Ivoire. Selection based on seed size by the farmers has resulted in subdividing the species into two cultivars: large-seeded and smallseeded. The morphological diversity study of the collection included 18 accessions and 24 traits. The multivariate analysis of variance (MANOVA) showed a significant difference between the two groups of cultivars. Principal component analysis on 13 traits pointed out variations among individuals, mainly on the basis of flower, fruit, and seed size. Dendrogram with UPGMA method allowed clustering of the cultivars. The genetic structure analysis among accessions using allozyme markers showed the following values: 18.95% for the proportion of polymorphic loci (P), 1.21 for the number of alleles (A) and 0.053 for observed heterozygosity (Ho). The level of the within accessions genetic diversity (HS = 0.188) was higher than the genetic variation among accessions (DST = 0.082). The estimates of F-statistics indicated a low level of genetic differentiation between accessions (FST = 0.298). Such a value suggested that L. siceraria maintains about 30% of its genetic variation among accessions. Nei genetic distances between the two cultivars were also low (0.002), indicating that cultivars were genetically similar enough to belong to the same genetic group