<b>Genetic dissimilarity among sweet potato genotypes using morphological and molecular descriptors

BackgroundSweet potato is an important root crop cultivated in different countries of the world. Its production and productivity are limited by factors such as the use of unimproved local varieties, pests, disease, and drought. To overcome these constraints, diversity in sweet potato genotypes could be a prerequisite for breeding programs. The present study aimed to determine the genetic diversity and nutritional composition of sweet potato accessions. One hundred accessions of sweet potato were collected from Nigeria and Niger for agro-morphological characterization and 50 of them were used for nutritional and molecular analysis. Eleven quantitative traits, six nutritional traits, and ten SSR markers were used for diversity analysis.ResultsAnalysis of variance (ANOVA) revealed significant differences (p < 0.01) among the sweet potato varieties for all the agro-morphological and nutritional traits studied. Accessions with orange flesh color had higher beta-carotene content compared to those with white, cream, and yellow flesh color. From the molecular diversity analysis, a total of 20 alleles were detected in 50 sweet potato accessions using 10 SSR markers. The average values for Na, Ne, I, Ho, He, and PIC were 2, 1.62, 0.55, 0.40, 0.37, and 0.30 respectively. Cluster analysis based on dissimilarity matrix grouped the accessions into two major clusters. Analysis of molecular variance (AMOVA) revealed 11% variation among the populations and 89% variation within the population, indicating low genetic variation among the populations and high genetic variation within population at p < 0.001.ConclusionOverall, variability was observed among the studied sweet potato accessions based on agro-morphological, nutritional traits and the SSR markers used. This will help breeding in using these genotypes for further improvement of the studied traits.

Sweet potato is an important staple crop and many varieties have been released into farmers’ fields in Nigeria, but no reliable means in tracking their identity, thus causing multiple naming of these varieties among farmers. The objective of the study is to establish objectively and reliable means of identifying released, local and elite sweet potato genotypes available in farmers’ fields. Thirty genotypes of sweet potato (Ipomoea batatas) species comprised IITA elites, local landraces and adaptable farmers’ varieties were planted at a space of 1m x 1m in a randomized complete block design in two replications. High genetic diversity was observed among the sweet potato genotypes examined. The morphological data revealed three distinctive clusters. In cluster I, purple vine, green petiole and light pink storage root colour were the dominant traits. While cluster II had dark green leaf at emergence and later changed to light green when fully expanded and the root cortex and pulp were white and cream colour, respectively. Cluster III exhibited different morphological characters. Two of the four isozyme markers examined, Aspartate amino transferase (AAT) and 6-phosphogluconate dehydrogenase (6 PGD) were more effective to discriminate sweet potato genotypes. AAT had 9 loci while 6-PGD had 10 loci and polymorphism ranged from 10.0% - 90.0% for AAT and 10.0% - 96.7% for 6-PGD. Isozyme data analysis revealed four clusters and insignificant correlations were observed between the isozyme and morphological analyses. The results could assist breeders in genetic diversity study of this crop and for its improvement.Keywords: Electrophoresis, isozyme markers, sweet potatos, morphology and polymorphisms

Sweet potato is an important staple crop and many varieties have been released into farmers’ fields in Nigeria, but no reliable means in tracking their identity, thus causing multiple naming of these varieties among farmers. The objective of the study is to establish objectively and reliable means of identifying released, local and elite sweet potato genotypes available in farmers’ fields. Thirty genotypes of sweet potato ( Ipomoea batatas ) species comprised IITA elites, local landraces and adaptable farmers’ varieties were planted at a space of 1m x 1m in a randomized complete block design in two replications. High genetic diversity was observed among the sweet potato genotypes examined. The morphological data revealed three distinctive clusters. In cluster I, purple vine, green petiole and light pink storage root colour were the dominant traits. While cluster II had dark green leaf at emergence and later changed to light green when fully expanded and the root cortex and pulp were white and cream colour, respectively. Cluster III exhibited different morphological characters. Two of the four isozyme markers examined, Aspartate amino transferase (AAT) and 6-phosphogluconate dehydrogenase (6 PGD) were more effective to discriminate sweet potato genotypes. AAT had 9 loci while 6-PGD had 10 loci and polymorphism ranged from 10.0% - 90.0% for AAT and 10.0% - 96.7% for 6-PGD. Isozyme data analysis revealed four clusters and insignificant correlations were observed between the isozyme and morphological analyses. The results could assist breeders in genetic diversity study of this crop and for its improvement. Keywords: Electrophoresis, isozyme markers, sweet potatos, morphology and polymorphisms

Information of the variation for important morphological and physiological traits of okra is still limited. Molecular analysis is an important additional tool in germplasm characterization studies. The study aimed to evaluate the performance of the growth and yield of 20 pre-commercial okra accessions to identify molecular markers’ association with morphological traits. Nineteen morphological traits were measured with five qualitative and 14 quantitative descriptors. For analysis of genetic patterns Random Amplified Polymorphic DNA (RAPD) markers were used with nine primers and 24 usable bands. The genetic dissimilarity was evaluated based in morphological and genetic matrices. Also, graphical representation of genetic distances was obtained by UPGMA and Tocher’s optimization method. The morphological characterization of the accessions detected polymorphism for all evaluated traits. RAPD markers were efficient in detecting genetic variability among okra accessions. For the primers used in the experiment, only OPE10 did not amplify the DNA strand. The other eight primers produced a total of 35 bands, in which 25 were polymorphic and ten were monomorphic. The morphological traits and molecular markers identified wide genetic variability among the 20 okra accessions, indicating successful crosses in breeding programs and isolating some interesting materials. Morphological and molecular cluster analyses were complementary and helped in the genotype selection. Molecular analysis indicated some divergent accessions that were not found in morphological analysis, which could highlight some materials that have a desirable trait, that is difficult and highly costly to access in field experiments.

Analysis of the physiological characteristics of several sweet potato genotypes at various watering levels in rainfed paddy field indicated that the adaptability of sweet potato genotypes was resistant to drought stress. This research aims to determine the physiological character and yield quality of several sweet potato genotypes (Beta 1 Variety, Perbaungan Accession, and Cengkeh Turi Accession) at various levels of watering (P1 (1 month watering), P2 (2 months watering), and P3 (4 months watering)) in rainfed paddy fields. The research was carried out in the paddy field of Tandem Hilir I Village Deli Serdang and the analysis was carried out in the Tissue Culture Laboratory of the Faculty of Agriculture, the University of Sumatera Utara from March-July 2019. The results of this research indicated that some sweet potato genotypes had no significant effect on the physiological character but had a significant effect on fresh tuber grading. Cengkeh Turi accessions with orange colour tuber had the highest production in the A-class fresh tuber grading category while the Perbaungan accession with orange colour tuber had the lowest production in C-class fresh tuber grading. The watering levels treatment also did not have a significant effect on the physiological character and tuber yield quality.

Morpho-agronomic and chemical analysis as well as RAPD markers were used to determine the genetic diversity among three Egyptian genotypes of sweet potato; Abees, Mabrouka and Gendawy. The results revealed that there is a wide variation among the three genotypes in most morphological and agronomic characters in addition to the nutritional values. Gendawy genotype had the highest values for most agronomic and chemical traits compared to the other two genotypes; therefore it is considered a good source of agronomic and nutritional traits for breeding. Regarding molecular characterization, a total of nine RAPD primers were used to assess the genetic variability and relationships among the three sweet potato genotypes. A total of 146 amplified bands were generated from the nine primers with 52.74% polymorphism indicating high genetic variability. Cluster analysis revealed a close genetic relationship between Abees and Gendawy genotypes (similarity value of 0.718), while Mabrouka was the most distinct genotype. Results concluded that RAPD analysis could not be effective in separating genotypes according to their morphological, agronomic or chemical characters. In addition, characterization based on these conventional characters should be complemented with DNA-based molecular characterization to reveal genetic diversity in the three Egyptian sweet potato genotypes.

In Bangladesh, sweet potato holds the fourth position as a crucial carbohydrate source, trailing rice, wheat, and potato. However, locally grown sweet potato varieties often display limited stability and yield. To tackle this challenge, diverse selection methods and statistical models were utilized to pinpoint sweet potato genotypes showcasing both stability and superior yield and quality traits. In the initial two years, multiple selection methods were employed to narrow down the collections based on preferences for yield and its contributing traits. Subsequently, a multi-environment trial (MET) was conducted in the following year to pinpoint superior and stable genotypes with desirable yield and quality characteristics. An integrated approach involving the Multi-Trait Genotype Ideotype Distance Index (MGIDI), Factor Analysis and Ideotype-Design (FAI-BLUP), and Smith-Hazel Index (SH) led to the identification of 71 superior sweet potato genotypes out of a total of 351 in the initial growing season. In the subsequent season, the MGIDI selection index was applied to the 71 genotypes, resulting in the selection of 11 top-performing genotypes. This selection process was complemented by a detailed analysis of the strengths and weaknesses of the selected genotypes. In the MET, the mixed effect model, specifically the linear mixed model (LMM), identified significant genotypic and genotype-environment interaction (GEI) variances. This points to elevated heritability and selection accuracy, ultimately boosting the model's reliability. By combining the strengths of LMM and additive main effects and multiplicative interaction (AMMI), the best linear unbiased prediction (BLUP) index identified H20 as the top-performing genotype for marketable root yield (MRY), H37 for dry weight of root (DW), H8 for beta carotene (BC) and H41 for vitamin c (VC). These genotypes surpassed the overall average in the WAAS index. For simultaneous stability and high performance, the WAASBY index selected H37 for MRY, H6 for DW, H61 for BC, and H3 for VC. Finally, genotypes H3 and H20 were selected using multi-trait stability index (MTSI), as they possessed high performance and stability. Based on the selection sense, the objective has been achieved with regards to the trait MRW, which serves as a major criterion for a superior variety of sweet potato.

Muluken Demelie 1 and Abiyot Aragaw 2 Ethiopian Institute of Agricultural Research (Werer Center), P.O. Box: 2003, Addis Ababa Ethiopia 1 International Potato Center – Ethiopia (CIP), .PO Box 10059 Addis Ababa, Ethiopia 2 ABSTRACT Sweet potato [ Ipomoea batatas (L.) Lam.] is important food security root crop in tropical and subtropical regions. It can tolerant of a wide range of edaphic and climatic conditions and grown with limited inputs. Genetic analysis reveals the genetic nature of the inheritance of tuber yield and yield components which is required to design efficient sweet potato improvement breeding strategy. Therefore, the objectives to determine genetic variability and to estimate the association of agro-morphological trait in sweet potato genotypes. Filed experiment was conducted at Were Agricultural Research Center using three varieties and eight accessions in Randomize Complete Block Design (RCBD) with three replications. Data were collected from twelve agro-morphological traits. This analysis of variance revealed significant (p<0.05) among sweet potato genotypes for all traits except stand count at sprout which showed non significant among sweet potato genotypes. Genotypes showed total tuber yield ranged from 123.67 to 370.04 with mean of 231.04 qt/ha while root weight 100 to 263 with mean of 168.04 gm. Newly released variety Ma’e gave highest yield. Genotypic coefficients of variation lower in magnitude than phenotypic coefficient of variation all agro-morphological traits. Genotypic coefficient of variation ranged from 0.77 (stand count at sprout) to 33.93 (unmarketable tuber yield) while phenotypic coefficient variation ranged between 3.47 (stand count at sprout) to 39.36 (unmarketable tuber yield). Heritability in broad sense was recorded for twelve traits ranged between 4.99% (stand count at sprout) to 86.45% (vine internode length). Genetic advance as percent mean ranged from 7.42% (stand count at harvest) to 60.27 (unmarketable tuber yield). Genotypic correlation higher in magnitude than corresponding phenotypic correlation for most of the traits. Genotypic correlation ranged from -0.56 (unmarketable and vine inter node length) to 0.98 (marketable and total tuber yield) while phenotypic correlation ranged from -0.56 (unmarketable and vine inter node length) to 0.97 (marketable and total tuber yield). This result suggested the importance of further collection to exploit the genetic variability between varieties and accessions for variety development of sweet potato in the country. Key words: phenotypic and genotypic coefficient of variation, heritability, genetic advance

The objective of this study was to evaluate the genetic diversity among traditional common bean accessions through morphological descriptors and molecular markers. Sixty-seven common bean accessions from the Germplasm bank of the Instituto Federal of Espírito Santo—Campus de Alegre were evaluated. For this, 25 specific morphological descriptors were used, namely 12 quantitative and 13 qualitative ones. A diversity analysis based on morphological descriptors was carried out using the Gower algorithm. For molecular characterization, 23 ISSR primers were used to estimate dissimilarity using the Jaccard Index. Based on the dendrograms obtained by the UPGMA method, for morphological and molecular characterization, high genetic variability was observed between the common bean genotypes studied, evidenced by cophenetic correlation values in the order of 0.99, indicating an accurate representation of the dissimilarity matrix by the UPGMA clustering. In the morphological characterization, high phenotypic diversity was observed between the accessions, with grains of different shapes, colors, and sizes, and the accessions were grouped into nine distinct groups. Molecular characterization was efficient in separating the genotypes in the Andean and Mesoamerican groups, with the 23 ISSR primers studied generating an average of 6.35 polymorphic bands. The work identified divergent accessions that can serve different market niches, which can be indicated as parents to form breeding programs in order to obtain progenies with high genetic variability.

The continuous rise in the atmospheric CO2 due to anthropogenic activities is likely to benefit crop species with C3photosynthetic pathway by enhancing photosynthetic efficiency and crop productivity. This is particularly importantin the context of climate change and food security of ever increasing population amidst scarcity of natural resources.In the search of photosynthetically efficient climate smart genotypes. In the present study, the net photosynthetic rate(Pn), stomatal conductance (gs) and intercellular CO2 (Ci) was studied in twelve contrasting sweet potato genotypes,viz. Sree Arun, Sree Badhra, Sree Kanaka, Kanhangad, Pusa Safed, Pusa Red, Kisan, Gouri, Sankar and ST-13, S-1464and S-1466 under ambient (400 ppm) and eCO2 (eCO2) (600, 800 and 1000 ppm) and the Pn at photosynthetic photonflux densities (PPFDs), viz. 200, 400, 600, 800, 1000, 1200 and 1500 μmol/m2/h at 30oC and 400 ppm CO2 usingportable photosynthesis system. The maximum Pn of ten sweet potato genotypes was recorded at PPFD of 1500μmol/m2/s and the increase in Pn at PPFDs above 1000 μmol/m2/s were insignificant. The Pn steadily increased dueto short-term (ten minutes) exposure at eCO2 concentrations between 400 ppm and 1000 ppm in twelve sweet potatogenotypes. The sweet potato genotypes had the average Pn of 26.30, 33.41, 38.02 and 40.32 μmol/m2/s at 400, 600,800 and 1000 ppm CO2 respectively. However, the per cent of increment in Pn at eCO2 significantly declined (average5.98%) at CO2 concentrations above 800 ppm. The genotypes Gouri, Sankar, Sree Arun, and S1466 had 61.00 – 74.3%hike in Pn at eCO2 (1000 ppm) as compared to ambient CO2 (400 ppm). The per cent increment in Pn significantlydecreased at CO2 concentrations above 600 ppm. The differences in Pn were statistically significant across sweetpotato genotypes and CO2 concentrations (P&gt;0.001), whereas the Pn had a quadratic relation with the increase inCO2 concentration (R2=0.603). The gs steadily decreased at eCO2 concentrations. The sweet potato genotypes hadthe average gs of 0.606, 0.508, 0.431, 0.376 mol H2O/m2/s at 400, 600, 800 and 1000 ppm CO2 respectively. Theper cent of decrease in gs at eCO2 significantly increased (average 38.33%) at 1000 ppm CO2. The differences ings were statistically significant across sweet potato genotypes and CO2 concentrations (P&gt;0.001). The sweet potatogenotypes had the average Ci of 271.50, 405.20, 543.00, and 684.00 μmol CO2/mol air at 400, 600, 800 and 1000ppm CO2 respectively. However, the per cent of increment in Ci at eCO2 significantly declined (average 25.70%) atCO2 concentrations above 600 ppm. The differences in Ci were statistically significant across sweet potato genotypesand CO2 concentrations (P&gt;0.001), whereas the Pn had a quadratic relation with the increase in Ci (R2=0.504). Theinteraction effect of genotypes and CO2 concentration on Ci, Pn and gs was insignificant. The differences in the totalchlorophyll and protein content in the leaves of sweet potato genotypes were statistically significant. Nevertheless,the gas exchange parameters were not influenced by the total chlorophyll and protein content.

The present work considered collecting and characterizing the genetic diversity of sweet potato [Ipomoea batata (L.) Lam.] in Ecuador through morphological and molecular descriptors (SSRs). Germplasm collections were made to assemble a national sweet potato collection for Ecuador. Characterization of the genetic diversity of this species was done through 34 morphological descriptors (24 qualitative and 10 quantitative), plus 12 exclusive descriptors for flowering and 8 microsatellites (SSRs). Three hundred and sixty-eight sweet potato accessions were collected in 18 provinces of Ecuador. Morphological characterization showed seven morphological groups and the variables with the greatest discriminating power for the description of the germplasm (p < .001) were the color, shape and defects of the reservoir root, in addition to the shape of the profile and lobes of the leaves. Principal component analysis determined the association of the main quantitative morphological features to the components. Eight microsatellite markers detected 89 alleles, with an average of 11.12 allele/locus and average polymorphism (PIC) of 0.848. STRUCTURE software revealed the formation of 4 different genetic groups. Morphological and molecular data did not show the formation of any group defined according to the province of origin. Factors such as the sweet potato reproductive system (cross-pollination), random sweet potato mutations and farmer exchange, contributed to the greater genetic diversity present. High genetic diversity and low number of duplicates were identified. This collection could provide outstanding genotypes to be used in breeding programs. Local landraces still in the hands of local farmers suggest that in situ conservation projects must be put in place.

Multivariate analysis of yield and quality traits in sweet potato genotypes (Ipomoea batatas L.)

Sweet potato (Ipomoea batatas L.) cultivation in Turkey is concentrated in one province situated in Mediterranean region only, which would not fulfill the domestic needs of the country soon. Therefore, cultivation of the crop in other provinces/climatic regions should be initiated to fulfill the domestic needs. The cultivation in other provinces requires thorough assessment of yield and quality traits of target crop. Therefore, yield and quality characteristics of four sweet potato genotypes (i.e., ‘Hatay Kırmızısı’, ‘Hatay Yerlisi’, ‘Havuc’ and ‘Kalem’) were assessed in the current study in Kazova and Niksar counties of Tokat province of the country having middle Black Sea climate in field experiments during 2018 and 2019. The cuttings of the genotypes were planted in Niksar during the second fortnight of April and first week of May in Kazova. The planting density was kept 90 × 45 cm. Data relating to number of storage roots, storage root weight, storage root yield per hill and storage root yield per hectare were recorded. Furthermore, quality traits, including dry matter ratio (%), protein ratio (%) and antioxidant ratio (%) of storage roots were also determined. The highest total storage root yield was recorded for ‘Havuc’ genotype during both years and locations, followed by ‘Hatay Yerlisi’ and ‘Hatay Kırmızısı’ genotypes. Overall, storage root yield (60.06 and 62.40 tons ha-1 during first and second year) recorded for the experiment at Niksar was higher than the storage root yield recorded for Kazova experiment (53.50 and 52.84 tons ha-1 during first and second year, respectively). The highest dry matter was produced by ‘Kalem’ and ‘Hatay Yerlisi’ genotypes during both years and at both locations, followed by ‘Hatay Kırmızısı’ and ‘Havuc’ genotypes. The storage roots of the tested genotypes accumulated higher dry matter at Kazova during both years. The highest protein content was obtained from the ‘Kalem’ genotype, and the protein contents of the ‘Hatay Yerlisi’ and ‘Hatay Kırmızısı’ genotypes were close to the ‘Kalem’ genotype. The results indicated that tested genotypes can successfully be cultivated in middle Black Sea climate. Therefore, production of sweet potato can be initiated in the future to meet the domestic needs for sweet potato in the country.

Sweet potato is an important food crop in Eastern Ethiopia, including the West Hararghe Zone. However, the area is still far behind in attaining the required optimum productivity of Sweet potato, this is due to biotic and abiotic factors, inappropriate Agronomic practices and lack of improved variety, to tackle these problems; variety improvement research is the major one. Therefore, the objectives of the study were to estimate the magnitudes of genotype, environment, and genotype by environment interaction effects on Sweet potato genotypes and to identify the high yielder and stable genotypes for wide adaptability in West Hararghe Zone, Eastern Ethiopia. The experiment was carried out at two locations (Mechara on station and Habro district) in three consecutive years (2018–2020) on 20 Sweet potato genotypes using a randomized complete block design (RCBD) with three replications. Additive main effects and multiplicative interactions analysis (AMMI) indicated that the yield performances of genotypes were under the major environmental effects of genotype by environmental interactions. The first two principal component axes (PCA 1 and 2) were significant (p≤0.01) and cumulatively contributed to 73% of the total genotype by environment interaction. In GGE bi-plot analysis using genotypic and environmental scores of the first PCA 1 and lower PCA 2 scores gave high yields (stable genotypes), and genotypes with lower PCA 1 and larger PCA 2 scores had low yields (unstable genotypes), as in the sites tested. Besides, genotypes G3 and G5 were stable across tested locations and gave higher total root yields (43.94t ha-1 and 49.34 t ha-1), respectively). However, G5 was recommended for possible release for wide adaptability in West Hararghe Zone and similar agro-ecology in the country. Res. Agric. Livest. Fish. 10(1): 43-52

Higher storage root yield with nutrient-rich sweet potato genotypes is essential to identify for the growers. Therefore, seven colour–fleshed sweet potato genotypes were investigated based on their growth, yield and nutri- tional qualities. This study explored the improved yield and nutritional quality of sweet potatoes. Sweet potato genotypes viz., G1 (BAU Sweet potato– 2), G2, G3 (BAU Sweet potato–4), G4 (BAU Sweet potato–3), G5 (BARI Sweet potato–2), G6 (BAU Sweet potato–1) and G7 were tested following randomized complete block design with three replications. Results showed that sweet potato genotypes exhibited wide variations in growth, storage root yield and quality traits. At harvest, vine length and leaf area were most significant in G6 and G3, while the highest fresh weight and gross yield were obtained from G5, which was statistically identical to G4. Except for twigs, anthocyanin, starch and sugar, the maximum storage contents were found in the roots. G1 contained the maximum anthocyanin and starch, while G2 contained the highest sugar. ?–carotene content was the highest in twigs, followed by leaves, leaf petioles and storage roots. The maximum ?–carotene was obtained from G3, followed by G2 and G1. Except for Ca, twigs retained maximum K, P, Fe and Zn, while Ca was the highest in leaves. G2 contained the maximum Ca and K, while G1, rich in P and G7, retained the maximum Fe and Zn. It can be concluded that G5, G4, G1 and G6 are the yield potential genotypes, while G2, G3 and G7 are anthocyanins, ?–carotene, Fe and Zn rich.