Search

Sweet potato is one of the most important crops being promoted for food security and nutrition in South Africa. This study investigated the nutritional and chemical compositions of four whitefleshed (Blesbok, Ndou, Monate, and Mvuvhelo) and three orange-fleshed (Bophelo, Impilo, and 199062.1) cultivars. The protein, ash, and crude fibre contents were analysed using standard AOAC procedures. The detection of fatty acids, sugar, and metabolites was carried out using Gas Chromatography–Mass Spectrometry (GC-MS). Carbohydrate and energy values were determined using standard methods. The results showed that Bophelo had the highest protein content (12.00%), with Blesbok having the lowest protein content (4.56%). The study also revealed that Impilo had the highest fibre (7.11%) and total sugar (22.21 %) contents. The highest ash content was found in 199062.1 (5.81 %) and the lowest was observed in Monate (4.50 %). Bophelo had the highest total fat content (0.650 %), with saturated, mono-saturated, and polysaturated fats of 0.270 %, 0.050 %, and 0.270 %, respectively, while the lowest fat content was observed in Impilo (0.380 %), with saturated, mono-saturated, and poly-saturated fats of 0.225 %, 0.020 % and 0.135 %, respectively. The highest total carbohydrate content was found in Blesbok (76.72 %). Different fatty acids, including palmitic acid (C16), stearic acid (C18), arachidic acid (C20), oleic acid (C18:1), and linoleic acid (C18:2) were also found in the sweet potato cultivars. This study demonstrated significant variations in the chemical composition of the cultivars, providing valuable insights for informed dietary decisions on consumption. [ABSTRACT FROM AUTHOR]

Sweet potato ((Ipomoea batatas L.) is a high-yielding nutritious specialty crop. There is a growing need for proactive information on sustainable production of sweet potatoes under short growing seasons. The objective of our study was to evaluate the effects of crop residue and synthetic mulches on the growth, yield, and quality parameters of three varieties of sweet potatoes. Three types of mulch, wheat straw (straw), white polyethylene film (white mulch), and black plastic film (black mulch), and a control (no mulch) were evaluated during the 2021 and 2022 growing seasons in the south-eastern region of Kazakhstan. The vine length, meristem number, tuber per plant, and tuber weight were significantly higher under white mulch and black mulch than under straw, and the results were significantly different from the control. The total yields of sweet potato tubers under white mulch and black mulch also varied significantly among the varieties, ranging from 20.5 t/ha for Rizi 0603 to 54.5 t/ha for Xushu 25. The results of the present study will be used to develop other technological sequences for the cultivation of sweet potatoes in the south-eastern region of Kazakhstan. More research is needed to ascertain the stability of the effects of varieties, mulch treatment, and their interactions on yields and to determine other treatments and varieties with better potential to improve sweet potato yields for cultivation in Kazakhstan.

Background: This study aimed to evaluate the sensory acceptability of four sweet potato cultivars (Beauregard, Morada‐INTA, Colorado‐INTA, and Arapey), considering two cooking methods: boiled and baked; and two cities, 9 de Julio (9DJ) and San Pedro (SP), of Buenos Aires province. 120 women were recruited in each city. A home use test was carried out. Each consumer received at home each sample in a bag containing three sweet potatoes and the evaluation form. The sensory acceptability of different characteristics of the samples was evaluated, before and after cooking. To inquire the reasons for consumption of each sample, the methodology check all that apply (CATA) was used. Results: Of the two factors evaluated (city and cooking method), city had a significant influence when evaluating the samples. Participants of SP gave higher acceptability to Beauregard cultivar than 9DJ in most attributes. Colorado INTA had greater acceptability in some descriptors by the consumers of 9DJ. While Arapey and Morada INTA had the greatest acceptability in 9DJ trial. In CATA results 9DJ consumers associated the Beauregard cultivar with negative phrases: It tastes weird and It has little flavor/tasteless and to a lesser extent to The internal color is artificial and It breaks when cooking. While SP consumers characterized with negative phrases the Arapey and Morada INTA samples as follows: It changes color (brown) quickly, Its shape is not regular and When cooked, it has threads or fibers. Conclusion: Consumer preferences provide opportunities for the development or improvement of new cultivars. It would be interesting to extend this study to other regions and/or countries. [ABSTRACT FROM AUTHOR]

Copyright of Lucrari Stiintifice, Universitatea de Stiinte Agricole Si Medicina Veterinara Ion Ionescu de la Brad Iasi, Seria Horticultura is the property of University of Agricultural Sciences and Veterinary Medicine (Editura Ion Ionescu de la Brad) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The nutritive value and potential use of two varieties of sweet potato (Ipomoea batatas) (LAM.) composite meal for growing rabbits was studied by comparing seven diets containing an increasing incorporation rate of Composite Sweet Potato Meal (CSPM) in replacement for maize. The composite sweet potato meal contained 65 % of whole root tubers and 35 % of the leaves and vines. The rabbits were randomly allocated into seven treatments. The two varieties of sweet potato i.e CIP440293 (Orange-Flesh) CSPM and TIS87/0087 (White-Flesh) CSPM replaced maize at graded levels 25, 50, 75 % respectively. The seven treatments are: T1 - 0 % Control, T2 - 25 % Orange Flesh, T3 - 50 % Orange Flesh, T4 - 75 % Orange Flesh, T5 - 25 % White Flesh Sweet potato, T6 - 50 % White Flesh Sweet potato and T7 - 75 % White Flesh Sweet potato. The treatments were performed in four replicates, each in a Completely Randomized Design (CRD) experiment. The diets contained 10.6 - 12.6 % of crude fibre, 16.4 - 17.6 % of crude protein and 10,9275 - 11,6728 MJ.kg-1 of metabolizable energy ad libitum. Eighty-four rabbit does, at twelve rabbits per treatments, were fed the seven diets from weaning (35 days, mean weight: 570.76 ± 42.09 g) to 98 d of age. The faecal digestibility of the diets was measured between 92 and 97 days of age in 6 rabbits per treatment. CSPM can be considered high-fibre roughage, as it contained 42.45 - 54.30 % of NDF (38.30 - 40.35 % of ADF and 13.30 - 20.40 % ADL) and 9.80 - 17.45 % of CP. The crude fibre digestibility was reduced with CSPM incorporation. Dietary incorporation of CSPM impaired the rabbit growth (18.08 vs. 14.66 g.day-1 during the period 77 - 98 days without CSPM). However, feed conversion was undermining with the high incorporation rate in feed. The dressing-out percentage of rabbits fed on diets containing the CSPM were comparable to the dressing-out percentage of rabbit fed the control diet. Health status or main slaughter traits were not affected by CSPM incorporation rate. Thus, CSPM had a comparable nutritive value for growing rabbits and it can successfully serve as a high-fibre feedstuff through its potential to supply low digested fibres (cellulose) and lignin. The two composite sweet potato meals could be considered as a high fibre source with a considerable high crude protein for the growing rabbits. The comparable dietary potential of the composites makes it an excellent replacement for maize, which is the conventional feed stuff, especially for hind gut fermenters like rabbits. [ABSTRACT FROM AUTHOR]

Sweetpotato (Ipomoea batatas, Convolvulaceae) is an important food crop in Sub-Saharan Africa (SSA). Lack of access to quality sweetpotato planting material after sweetpotato limits utilization of market oriented improved clones and new varieties. Obtaining clean planting material in the right quantity and quality is a challenge in the SSA region. Farmers often obtain planting materials from their own sources with multiple rooting, drawn from a previous crop or neighbors and face the risk of it being infected with sweetpotato viruses. The objective of this study was to examine the economic and physical yield performance of sandponics multiplication method by comparing with conventional soil method using optimal N-nutrient inputs. The performance of five sweetpotato cultivars (Irene, Delvia, Tanzania, Gweri, and Kabode) in the modified prototype sweetpotato nutrient media was evaluated. Vine production utilizing modified sandponics nutrient media with trellised plants was compared to the conventionally used soil media. Analysis of variance indicated that the main effects of cultivar and substrate were highly significant (p < 0.0001) for nodes produced, vine multiplication rate (VMR), number of cuttings produced, and vine length. In addition, cultivar by substrate interaction was highly significant at 0.01 probability level for nodes produced, VMR, and vine length. Vine multiplication rate was 33% higher in the sandponics system compared to the conventional soil method of multiplying sweetpotato vines. Among the cultivars studied, Irene was the most favorable cultivar with a VMR of 65.2 in sand and 45.5 in soil. The cost-effectiveness analysis indicates that the cost per cutting (i.e., 3–4 nodes) produced from sandponics method was 4.6 KSH (US$ 0.046) as compared to 3.1 KSH (US$ 0.031) per cutting produced from conventional method. Sandponics system is competitive due to its capability of increased VMRs. However, the optimal number of ratooning needs to be investigated to understand the economies of scale in future research. [ABSTRACT FROM AUTHOR]

The kinetic, modeling and optimised processing parameters for the extraction of phenolic antioxidant from an orange flesh sweet potato cultivar using an aqueous medium was studied. For the process to be effective; reaction time (t), temperature (T) and solid-to-solvent ratio (E) were optimised using the response surface methodology (RSM) and the artificial neural network (ANN) algorithms. Linear interaction between solid to solvent ratio was established to be most significant. Processing variables were established to make 30.44% (T), 38.75% (E) and 30.81% (t) roles to the efficiency of the system. Optimal parameters of 90 °C (T), 6.79% (E) and 60.5 min (t) were established as optimum processing variables using the RSM while ANN algorithm predicts optimal extraction conditions points of 98.64 °C (T), 11.68% (E) and 60.5 min (t). ANN algorithm was the best tool for optimum points prediction due to its low values of mean relative per cent deviation modulus and its absolute average deviation. Antioxidant properties of noodles improved with fortification with 1% peel extract. Optimization conditions and predictive models described in this studies offers an opportunity for the formulation of food products with functional properties by food processor. [ABSTRACT FROM AUTHOR]

Highlights • A mineral and centesimal evaluation of sweet potatoes was performed. • The results showed that organic samples showed high mineral content. • Conventional culture samples showed high sodium content. • Multivariate analysis proved to be a good tool to evaluate different forms of cultivation. Abstract Sweet potato is a food consumed in the world. In this work, the minerals and centesimal composition in sweet potatoes of organic and conventional cultivars was investigated. The accuracy was confirmed with a certified reference material of apple leaves (NIST 1515). The quantification of the samples was performed by inductively coupled plasma optical emission spectrometry and the digestion efficiency was evaluated by residual carbon content. The mean concentrations (in mg/100 g) of minerals were: 23.5 and 40.7 (Ca); 0.082 and 0.159 (Cu); 0.303 and 0.481 (Fe); 197 and 381 (K); 166 and 35.7 (Mg); 0.183 and 1.15 (Mn); 68.6 and 0.433 (Na); 54.1 and 62.2 (P) and 0.197 and 0.261 (Zn) for conventional and organic cultivars, respectively. Average centesimal concentrations in conventional and organic cultivars (in %), were: 72 and 72 (moisture); 0.87 and 0.90 (ashes); 1.5 and 1.4 (proteins); 0.63 and 0.54 (lipids) and 24.8 and 23.9 (carbohydrates). [ABSTRACT FROM AUTHOR]

Main conclusion: Transcriptome analysis was performed on the roots of susceptible and resistant sweetpotato cultivars infected with the major root-knot nematode species Meloidogyne incognita. In addition, we identified a transcription factor-mediated defense signaling pathway that might function in sweetpotato-nematode interactions.Root-knot nematodes (RKNs, Meloidogyne spp.) are important sedentary endoparasites of many agricultural crop plants that significantly reduce production in field-grown sweetpotato. To date, no studies involving gene expression profiling in sweetpotato during RKN infection have been reported. Therefore, in the present study, transcriptome analysis was performed on the roots of susceptible (cv. Yulmi) and resistant (cv. Juhwangmi) sweetpotato cultivars infected with the widespread, major RKN species Meloidogyne incognita. Using the Illumina HiSeq 2000 platform, we generated 455,295,628 pair-end reads from the fibrous roots of both cultivars, which were assembled into 74,733 transcripts. A number of common and unique genes were differentially expressed in susceptible vs. resistant cultivars as a result of RKN infection. We assigned the differentially expressed genes into gene ontology categories and used MapMan annotation to predict their functional roles and associated biological processes. The candidate genes including hormonal signaling-related transcription factors and pathogenesis-related genes that could contribute to protection against RKN infection in sweetpotato roots were identified and sweetpotato-nematode interactions involved in resistance are discussed. [ABSTRACT FROM AUTHOR]

Temperature is considered as a major environmental factor upon which the storage behavior of sweetpotatoes depends. To quantify shoot and root vigor responses during sweetpotato early transplant establishment, an experiment was conducted using sunlit environmental growth chambers at three day/night temperatures, 22/14 (low), 30/22 (optimum), 38/30 °C (high). Ten sweetpotato cultivars were transplanted in pots for 20 days and several shoot and root morphological and physiological traits were assessed. Sweetpotato cultivars varied significantly for many traits measured particularly root components. High and low temperatures significantly decreased the production of storage root number. Low temperature caused a marked decrease in vine length, node number, leaf area, total biomass, and net photosynthesis causing 95, 70, 78, 66, and 36% reduction compared to the optimum temperature. At high temperature, average leaf area was seven times more than optimum indicating strong temperature effects on leaf number, size, and leaf area development. Principal component analysis was used to classify sweetpotato cultivars to low and high-temperature tolerant, intermediate, and sensitive groups. The sweetpotato cultivars O’henry and Bonita were identified as tolerant, Evangeline, B14, Vardaman, and Covington as intermediate tolerant, and NC05198 and Travis as sensitive to both low and high temperatures. A poor correlation was observed between low and high temperature response indices indicating that cold and heat tolerance mechanisms are different and the selection has to be made independently in developing tolerance to low and high temperatures. The identified low and high temperature tolerant cultivars and their associated morpho-physiological characteristics may be useful for breeders to develop new cultivars that could withstand variable temperatures projected to occur in future climates aiming to increase storage root yield. [ABSTRACT FROM AUTHOR]

Background: Biofortified orange-fleshed sweetpotato (OFSP) varieties are being promoted to reduce vitamin A deficiencies due to their higher beta-carotene content. For OFSP varieties to have impact they need to be accepted and consumed at scale amongst populations suffering from vitamin A deficiencies. Objective: We investigated the sensory and cultural acceptability of OFSP varieties amongst households with children aged between 2–5 years old in two areas in Central and Southern Malawi using an integrated model of the Theory of Planned Behavior (TPB) and the Health Belief Model (HBM). Methods: Sensory acceptability was measured using a triangle, preference and acceptance test using three OFSP varieties and one control variety, among 270 adults and 60 children. Based on a food ethnographic study, a questionnaire on cultural acceptability was developed and administered to 302 caretakers. Data were analyzed by calculating Spearman’s correlations between constructs and multiple linear regression modeling. Results: The sensory evaluation indicates that all three OFSP varieties are accepted (scores >3 on 5-point scale), but there is a preference for the control variety over the three OFSP varieties. Almost all caretakers are intending to frequently prepare OFSP for their child in future (97%). Based on regression analysis, the constructs ‘subjective norms’ (β = 0.25, p = 0.00) reflecting social pressure, and ‘attitudes toward behavior’ (β = 0.14 p = 0.01), reflecting the feelings towards serving their child OFSP, were the best predictors for caretakers’ behavior to prepare OFSP for their child. Conclusions: Our study shows that both sensory and cultural attributes can influence acceptability of varieties and consumption amongst households with children. Considering these attributes can improve the impact of biofortified crops in future programming, by reducing Vitamin A deficiencies through the intake of these nutrient-rich crops. [ABSTRACT FROM AUTHOR]

Highlights • The optimum cultivated conditions of purple-flesh sweet potato Xz3 were determined by orthogonal experiments L 9 (34). • The main traits of Xz3 mostly increased at the early growing stage and maximized after 90 DAT. • Anthocyanin accumulation of Xz3 is fluctuating during the growth period and usually determined in the early stage. • Applying rich fertilizer and extending growth period reasonably can increase yield of Xz3 and its anthocyanin production. Abstract The cultivation technique and growth dynamics of purple-fleshed sweetpotato ( Ipomoea batatas [L.] Lam) have not been extensively addressed. The objectives of the present study were to explore the optimum cultivation conditions and growth characteristics of purple-fleshed sweetpotato Xuzishu 3, which is a new cultivar with high anthocyanin content, good germination and nice agronomic traits. Through the analysis of orthogonal experiments L 9 (34), the use of 300 kg/ha of K fertilizer, the planting 50,250 plants per hectare, and the growth for 120 DAT were regarded as optimum conditions for Xuzishu 3. The agronomic traits, qualitative characteristics and biomass accumulation of Xuzishu 3 during the six growth periods were measured to discuss the dynamic changes of its essential characteristics and yield accumulation. The main traits of Xuzishu 3 revealed sigmoidal or linear patterns during these growth periods. Most of the traits appeared as peak values after 90 DAT, except for anthocyanin, soluble sugar and protein content. Extremely significant positive correlations were found between dry matter rates of the up-ground parts (including leaf petioles, leaves and stems). Meanwhile, each of these had extremely significant positive correlations in terms of reducing sugar content and storage root weight per plant, respectively. Furthermore, the assimilated product distributed more in the stems and leaves than in storage roots before 90 DAT. Subsequently, the partition of assimilates to the storage roots rapidly increased and peaked at 135 DAT, even though the photosynthetic capacity and net assimilation rate decreased. The data and inferences in the present study not only improved the yield and quality of Xuzishu 3, but also provided a method to more precisely optimize the cultivation of purple-fleshed sweetpotato. [ABSTRACT FROM AUTHOR]

Overproduction of reactive oxygen species (ROS) will promote oxidative damage and can induce reproductive disorder. A therapeutic strategy to reduce effects of reproductive disorder is by maintaining the balance between ROS and antioxidants. Black soybean (BSB) contains phenolic compounds and has a greater antioxidant capacity than yellow soybean. Purple sweet potato (PSP) also has antioxidant capacity, due to the presence of anthocyanin, but is low in protein. The combination of BSB and PSP is expected to limit symptoms of reproductive disorder through decreasing ROS levels, enhancing testosterone production, and improve sperm quality. The results of this study indicate that the combination of PSP and BSB could restore blood glucose levels, improve seminiferous tubules diameter, decrease ROS production, and improve testosterone and sperm quality. A ratio of BSB to PSP of 2:2 and 3:1 were effective to improve symptoms of reproductive disorder in the type 2 diabetes mellitus (T2DM) rat model. [ABSTRACT FROM AUTHOR]

Abstract: Two orange‐fleshed sweet potato cultivars: Apomuden and “Nane” were grown on cow dung‐, chicken manure‐, compost‐amended soils, and untreated soil. Apomuden is a variety, while “Nane” is being evaluated to be released in Ghana. The storage roots (SRs) were harvested at 3 months, cured by heaping the SRs and covering with the sweet potato foliage for 7 days in the field. The cured SRs were kept in an evaporative cool chamber to study the effect of soil amendment treatments on weight loss, rot, some nutrient composition, and sensory attributes. Boiled SRs were assessed by 70 untrained panelists after 7 weeks of storage based on the following: general appearance, sweetness, finger‐feel firmness, and overall acceptability using a 5‐point hedonic scale (1 = dislike extremely to 5 = like extremely). Percent rot for “Nane” showed a linear trend, while that of Apomuden was nonlinear. Both cultivars showed similar trends in terms of cumulative weight loss with “Nane” recording lower weight loss compared with Apomuden. A significant (p < 0.001; r = 0.71) strong positive correlation was observed between weight loss and rots. “Nane” had higher dry matter (37.15% vs. 30.19%; p < 0.001, respectively) and starch content (59.16% vs. 51.86%; p < 0.001, respectively) than Apomuden. Stored SRs grown on chicken manure‐amended soil recorded the highest protein (6.41%; p < 0.001) and β‐carotene (16.64 mg/100 g; p < 0.001) content than the other treatments. There was a 35% decline in β‐carotene for Apomuden, while “Nane” increased by 24% at the end of the 7‐week storage. “Nane,” the cultivar with high dry matter content had good storage properties than Apomuden. Stored SRs cultivated on soils amended with chicken manure had higher β‐carotene and protein content. All sensory attributes ranged from 3.35 to 3.68 indicating a good consumer preference for both cultivars irrespective of the soil amendment treatment applied. [ABSTRACT FROM AUTHOR]

Sweet potato (Ipomoea batatas) cultivars 'Bosbok' and 'Mvuvhelo' were previously shown to be resistant to Meloidogyne incognita race 2, without information on the mechanism of resistance. Among the two mechanisms of nematode resistance, the latter is the only one that is useful in plant breeding programmes. The objective of this study was to determine the existing nematode resistance mechanism in cultivars 'Bosbok' and 'Mvuvhelo' to M. incognita race 2. Uniform rooted cuttings in 250 ml polystyrene beakers containing fine sand were inoculated with 100 second stage (J2) with four plants harvested every other day for 30 days. Roots were severed, cleaned, stained and then distained, assessed under the stereomicroscope for the existence of (1) necrotic spots, (2) poorly developed giant cells, (3) formation of rootlet interferences, (4) absence of root galls and (5) non-detectable J2 in roots. All plant variables over time exhibited quadratic relations with coefficients of determination ranging from 65 to 85% and from 72 to 94% in cultivars 'Bosbok' and 'Mvuvhelo', respectively. In conclusion, the two cultivars were shown to contain post-infectional nematode resistant attributes and could, therefore, be candidates to serve in introgression intended for breeding nematode-resistant sweet potato cultivars. [ABSTRACT FROM AUTHOR]

Copyright of Revista Caatinga is the property of Revista Caatinga and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In various parts of the world, drying technologies have been developed to convert tubers into flour which can be used as ingredients in numerous food products. Potato and sweet potato are known to contain certain bioactive constituents that are capable of scavenging free radicals and reducing the risk of degenerative diseases. The effects of two drying methods (sun and solar) on flour yield, antioxidant activity and phytochemical composition of Irish potato (IP) and two sweet potato varieties (orange and white-fleshed) were evaluated. The flour yield (15.20-19.0%) varied significantly (p<0.05) among the samples. The DPPH (1, 1-diphenyl-2-picrylhydrazyl) free radical scavenging activities of the flour samples varied with drying methods and the extracts' concentrations. The total antioxidant activities expressed in terms of the % inhibition (53.58-90.62%) and EC50 values (0.584-45.214 mg/ml) were observed to be significantly affected (p<0.05) by the drying methods. Drying processes generally increased the total phenolics (18.72-21.60 mg GAE/g) and total flavonoids (0.50-1.15 mg QE/g) contents of the tubers. The effect of sun-drying was observed to be less favorable on the white-fleshed sweet potato (WFSP) samples compared to solar-drying method. Although solar-dried orange-fleshed sweet potato (OFSP) flour had the highest total antioxidant activity, sun-drying method produced IP and OFSP flours with the highest total phenolics and total flavonoids contents respectively. Sun and solar dried OFSP had the highest beta-carotene content (BCC) and only the BCC of Irish potato significantly varied (p<0.05) with drying methods. This study also revealed that the effects of drying methods on the yield, phytochemical and antioxidant activities of the samples were mostly tuber (potato and sweet potato) dependent. [ABSTRACT FROM AUTHOR]

To characterize the differences in photosynthate distribution and transport between nitrogen(N)-tolerant and N-susceptible sweetpotato cultivars under different N conditions, three N levels, including 0 (N0), 120 (N120), and 240 kg ha−1 (N240), were used in field experiments with the Jishu26 (J26) and Xushu32 (X32) cultivars in 2015 and 2016. The results from both years revealed that high N application reduced the tuberous root yield, the tuber/vine rate of carbon-13 (13C), and top-to-base (three equal segments of stem divided from the fifth opened leaf of the shoot tip to the main stem, defined as the top, middle, and base parts, respectively) gradients such as sucrose, ammonia N and potassium along the stem. ‘J26’ showed a higher yield than ‘X32’ under N0 but lower yield than ‘X32’ under N120 and N240. It also exhibited a higher 13C distribution to tuberous roots compared with that of ‘X32’ under N0, and the opposite trend was observed under N120 and N240. Under N0, ‘J26’ showed a steep top-to-base amino acid gradient and a significantly lower top-to-base sucrose increase along the stem in the late growth stage. Under N120 and N240, ‘X32’ exhibited a greater top-to-base decrease in the ammonia N along the stem during the main growth stages, a steep top-to-base sucrose gradient along the stem in the early growth stage, and a lower top-to-base sucrose increase along the stem in the middle and late growth stages. The formation of a reasonable photosynthate distribution structure attributed to high yield was related to a desirable sucrose, ammonia N or K+ gradient downward along the stem. These results might help provide farmers with sweetpotato cultivars using less or no N fertilizer in soils of different fertility and enhance the knowledge of yield-related physiology. [ABSTRACT FROM AUTHOR]

Cilembu sweet potato is a unique commodity with high demand market due to its sweet taste. The objectives of this study were to investigate the production performance of Cilembu sweet potatoes in term of production classes and critical limit and to determine discriminating land characteristics classes of yield and total sugar content. This study was conducted in Cilembu sweet potatoes production centers in West Java. Sweet potatoes tuber and soil samples were collected by purposive random sampling during harvest. Cilembu sweet potatoes production classes were defined by decreasing yields criteria in land evaluation. Critical limit production was the lowest yield and total sugar content of raw tuber which harvested in Cilembu village. Discriminating land characteristics were decided by discriminant analysis. Results showed that there was a significant different yield between typical and nontypical areas. Critical limit of yield and total sugar content were 10.5 t ha-1 and 2.32 %, respectively. The discriminating land characteristics of yield classes were soil properties (pH, CEC, P, Ca, Mg, ΔT), and monthly rainfall, whereas for total sugar content classes were effective soil depth, clay, sand and monthly rainfall. These variables are proposed as diagnostic criteria in Cilembu sweet potato land suitability criteria. [ABSTRACT FROM AUTHOR]

[Objective] T1 lis research aimed to select suitable purple sweetpotato varieties of fresh food type and sweetpotato granules processing type in hilly regions of middle Sichuan. [Method] In Jintang County of Sichuan, 23 purple sweetpotato varieties (strains) have been introduced to analyze main quality characteristics changes with 4 Nansishu 008 ’ as control from 2009 to 2014. [Result] The good cooking and eating quality, moderate dry matter rate and starch content and high soluble sugar content could be used as main selecting indexes of purple sweetpotato varieties of fresh food type. The highest three taste valuation varieties were 4 Yuzi 263' , 4 Nanzishu 008 4 and 4 Nanzishu 014 ’ with the dry matter rate being 27. 52 % -31. 34 % , starch content being 17. 20 % -22. 17 % , soluble sugar content being 6. 75 % -10. 38 % and fresh tuber yield being 22 597 -25 312 kg/hm2 High anthoeyanidin content and dry matter rate, high and stable fresh tuber yield could be used as main selecting indexes of purple sweetpotato varieties of granules processing type. The highest three anthoeyanidin content varieties were 4 Mianzishu 9 4 , Nonglin 47 ’ and 4 Xuzishu 3' with the anthoeyanidin content being 40. 76 - 53. 93 mg/100 g FW, dry matter rate being 32. 43 % -38. 20 % , fresh tuber yield being 18 295 -31 850 kg/hm2 and coefficient of variation being 16. 68 % -21. 71 %. [Conclusion]The purple sweetpotato varieties were suitable to be recommended according to their uses in hilly regions of middle Sichuan. 4 Yuzi 263', 4 Nanzishu 008' and 4 Nanzishu 014 ’ could be used as suitable fresh food varieties while 4 Mianzishu 9 4 , 4 Nonglin 47' and 4 Xuzishu 3' could be used as suitable granules processing varieties. [ABSTRACT FROM AUTHOR]

Hydrothermal carbonization (HTC) of sweet potato waste was performed to investigate the effect of process parameters including reaction temperature (180–300 °C) and residence time (0–120 min) on the characteristics of hydrochars. The results showed that the increase of reaction temperature and residence time both decreased the yield of hydrochars. With the increase of reaction temperature and residence time, the carbon content of hydrochars increased, while the hydrogen and oxygen contents decreased. The lower H/C and O/C ratios indicated that dehydration and decarboxylation reactions occurred during HTC. The occurrence of aromatization reaction was found in FTIR spectra. Thus, the fixed carbon content, higher heating value, and energy density of hydrochars increased. SEM analysis indicated that HTC developed rough surface with crack on the hydrochars. The thermogravimetric experiments displayed the increase trend in combustion ignition temperature, burnout temperature and activation energy as reaction temperature and time increase, which showed better combustion characteristics. [ABSTRACT FROM AUTHOR]

Sweet potato weevils (Cylas spp.) are among the most important constraints to sweet potato (Ipomoea batatas [L.] Lam.) production in most agro-ecological zones of Tanzania. Integration of farmers’ perception on sweet potato weevil damage, production constraints, and variety preferences is crucial in developing sweet potato varieties with farmer-preferred traits and weevil resistance. The aim of this study was to identify farmers’ perceptions on sweet potato weevil damage, production constraints, postharvest storage options, and criteria used to select and grow the best sweet potato varieties in western Tanzania. Surveys were conducted in four selected districts of western Tanzania (Nzega, Sikonge, Kigoma rural, and Kasulu) known for sweet potato production. Data were collected using a structured questionnaire, focus group discussions (FGDs), and transect walk involving 122 sweet potato farmers. Weevil damage was reported by 84% of the respondents to be the overriding constraint to sweet potato production. Sweet potato diseases and drought were the next production constraints, reported by 57% and 54% of the respondents, respectively. Farmers’ preferred agronomic traits of sweet potato included high yield (25% of respondents), drought tolerance (24%), and disease and pest resistance (21%). Farmers’ preferred sweet potato culinary traits in the study areas were high dry matter content (reported by 21% of the respondents), followed by reduced cooking time, taste and fiber content (each reported by 19% of the respondents). The above-mentioned production constraints and farmers’ preferred traits are useful selection criteria for improving sweet potato with respect to weevil resistance and enhanced storage-root yield and quality. [ABSTRACT FROM AUTHOR]

Abstract: Sweetpotato French fries (SPFF) are growing in popularity, however limited information is available on SPFF textural properties in relation to chemical composition. This study investigated the relationship between chemical components of different sweetpotato varieties and textural characteristics of SPFF. Sixteen sweetpotato genotypes were evaluated for (1) chemical constituents; (2) instrumental and sensory textural properties of SPFF; and (3) the relationship between chemical components, instrumental measurements, and sensory attributes. Dry matter (DM), alcohol‐insoluble solids (AIS), starch, sugar, and oil content, and also α‐ and β‐amylase activities were quantified in raw sweetpotatoes and SPFF. Peak force and overall hardness describing instrumental textural properties of SPFF were measured using a texture analyzer. Descriptive sensory analysis was conducted and 10 attributes were evaluated by a trained panel. Results showed that DM, AIS, and starch content in raw sweetpotatoes were significantly correlated (P < 0.05) with instrumental peak force and overall hardness (r = 0.41 to 0.68), and with sensory surface roughness, hardness, fracturability, and crispness (r = 0.63 to 0.90). Total sugar content in raw sweetpotatoes was positively correlated with sensory smoothness and moistness (r = 0.77), and negatively correlated with instrumental peak force and overall hardness (r = –0.62 to –0.69). Instrumental measurements were positively correlated with sensory attributes of hardness, fracturability, and crispness (r = 0.68 to 0.96) and negatively correlated with oiliness, smoothness, moistness, and cohesiveness (r = –0.61 to –0.91). Therefore, DM, AIS, starch, and total sugar contents and instrumental measurements could be used as indicators to evaluate sweetpotato genotypes for SPFF processing. Practical Application: In recent years, sweetpotato French fries (SPFF) have grown in popularity, but limited information is available on SPFF textural properties in relation to the differences in chemical constituents among sweetpotato varieties. This study demonstrated that sensory texture attributes of SPFF varied widely and were significantly correlated with chemical components such as dry matter, starch, and total sugar contents of raw sweetpotatoes and instrumental texture measurements of SPFF. The knowledge generated from this study will benefit the food industry and breeding programs with the selection of sweetpotato varieties for improved SPFF quality. [ABSTRACT FROM AUTHOR]

This study estimated the amount of loss in storage roots caused by various levels of damage caused by sweetpotato weevils (Cylas spp). Seven varieties of sweetpotato (Ipomoea batatas L. (Lam)) were evaluated in three production sites in northern Ghana for two years (2014 and 2015). Yield data for each experimental plot were collected. A regression analysis was carried out using the generalized linear model approach. In the study, nonmarketable roots were classified as all undersized roots (<100g) and spoilt roots due to weevil, millipede, and soft rot. The results indicated weevil damage as the only significant predictor of nonmarketable yield at 5% level of significance. From the study, the average values for total root yield, marketable root yield, and nonmarketable root yield were 9.39, 6.71, and 2.67 ton/ha respectively. The minimum weevil damage (score 2) resulted in a yield loss of 2 ton/ha which represents 8.3% while severe damage at score 9 could cause a loss of 7.43 ton/ha of storage roots representing 31% of the attainable yield of sweetpotato. Weevil susceptibility needs to be treated as a serious trait when evaluating sweetpotato genotypes to be released as varieties. [ABSTRACT FROM AUTHOR]

There is little published information on sensory attributes and quality indices of organically grown sweetpotato (Ipomea batatas L.) even though there is a growing demand for this product. A study was conducted to identify the best cultivars based on sensory characteristics and organoleptic acceptability of sweetpotato grown under an organic management production system. Baked samples of 14 sweetpotato cultivars were evaluated by taste panelists on a 4-point hedonic scale for color, taste, texture, and overall acceptability. The cvs. All Purple (purple fleshed), Carolina Ruby (orange fleshed), and Ginseng (orange fleshed) had the highest taste, texture, and aroma scores; the white fleshed cv. Japanese Purple was least accepted overall. The most preferred sweetpotato cultivar was associated with the descriptors pasty, umami (monosodium glutamate like), sodium, and adhesive. The purple flesh color was well liked by all panelists and rated as the top color of all cultivars. Panelist preference was toward nontraditional cultivars. [ABSTRACT FROM AUTHOR]

The objectives of the present study were firstly to analyse the genetic relatedness among three Slovenian sweet potato varieties; and secondly to assess the effects of different growing media on selected agronomic and nutritional traits of these varieties. Tubers of three varieties (Lučka, Janja, Martina) with different skin/flesh colour were produced in planters under glasshouse conditions in five different growing media (perlite, peat, expanded clay, vermiculite, garden soil) from prior raised seedlings. Genetic analysis was performed using a set of eight single sequence repeats markers. According to Nei's genetic distance and pairwise population Fst analysis, the most related varieties are Janja and Martina; in contrast, Lučka and Martina show the weakest genetic relationships. The following agronomic traits were evaluated: vine length, thickness of vine-base, number of branches, weight of above ground part, number of leaves plant-1, number of tubers plant-1 and tubers weight plant-1. Between nutritional traits total phenolic content (TPC), antioxidant potential (AOP) and ascorbic acid content (AA) were determined in the range: 36.2 to 65.1 mg gallic acid equivalent 100 g-1 fresh weight, 0.18 to 0.56 mg Trolox equivalents g-1 FW and 13.7 to 23.5 mg 100 g-1 FW, respectively. Significant interactions of growing media (factor A) × variety (factor B) were observed for thickness of vine-base, weight of above ground part, AOP, TPC and AA. Overall, results showed variation in varieties response to growing media. Growing media provide a discriminant classification of the sweet potato varieties according to their agronomic and nutritional traits. [ABSTRACT FROM AUTHOR]

This study was conducted in El-Kanater El-Khyria Research Station. Kalubia Governorate during two seasons 2014 and 2015 to evaluate three varieties of sweet potatoes, one was recorded at the Institute of Horticulture Research compared to two local varieties (V.B and V.C) cultivated in Egypt and the aim items for use in the work of sweet potato soup rich in nutrients. The results showed that the significant differences were found among three varieties in most traits. Significant differences for plant growth characters (number of branches and leaves on main stem, length of stem main and neck leaf and weight of vin), yield and its component (total yield per plant of tuber roots /Kg), average weight of one storage root (gm), number of tuber roots per plant and average of tuber root (length and diameter). Data showed that ether extract, protein and fiber were significantly higher in local V.B (orange sweet potato) than that found in local V.C (white sweet potato) and new V Min.6 (yellow sweet potato). The data showed that significant differences in total carotenoid and β-carotene were found among all the sweet potato cultivated. Mixing whole wheat, skimmed milk and lentil with sweet potato varieties improved the amino acid profile, nutritional quality, protein digestibility and bioavailability of β-carotene. The values of calculated protein efficiency ratio (PER) of the soup samples were 2.72 to 3.35. The findings show that acceptable soup could be produced from the tuber root of different varieties of sweet potato compared to the control soup (without sweet potato). In conclusion, soup sweet potato is recommended for the elderly and small children since it contains more protein and vitamin A which enhances eyesight. The new V Min 6. showed that the highest values in most traits under study could be recommended for using in commercial production and industrial soup. [ABSTRACT FROM AUTHOR]

The genetic diversity available in sweetpotato has not been explored to develop dual-purpose sweetpotato varieties (DPSVs). The objectives of this study were to assess the level of phenotypic diversity present among sweetpotato varieties grown in Rwanda, and to select suitable parents for breeding DPSVs. Fifty-one diverse sweetpotato genotypes were evaluated in field trials conducted at the Rubona and Karama experimental stations of the Rwanda Agriculture Board using a 6 × 9 unbalanced alpha lattice design with three replications. Genotypes and sites showed significant interaction (P < .05), indicating differential response of genotypes in fresh root yield (FRY), root dry matter content, dry root yield (DRY), marketable root number, marketable root weight, flowering frequency and harvest index. The top two genotypes selected for their high FRY were RW11-4923 (20.9 t ha−1) and RW11-2419 (20.18 t ha−1). RW11-4923 and Wagabolige were the best performers for vine yield, producing 23.67 and 23.45 t ha−1of vines, respectively. Ukerewe performed well for its DRY (7.09 t ha−1), while RW11-4923 had the highest mean dry vine yield (5.17 t ha−1). RW11-2910 and 8-1038 had root-to-vine ratios of 2.0 and 1.5, respectively, suggesting their suitability as breeding parents, to breed DPSVs. Two main phenotypic groups with 10 sub-groups were detected through cluster analysis. Principal component analysis showed that the first four components accounted for 76.33% of the phenotypic variation present among the 51 genotypes. The selected sweetpotato genotypes that had a combination of high storage root yields and heavy vine production should be used as parents in developing DPSVs, concurrently incorporating farmer-preferred traits. [ABSTRACT FROM AUTHOR]

【Objective】 The aim of this study was to explore the identification methods and resistance of different sweet potato varieties to weevil for breeding of weevil-resistant sweet potato varieties provide theoretical basis. 【Method】 By setting different resistance indexes, under the condition of single factor variable, network room and laboratory tests were carried out respectively, investigated and analyzed the damage of weevils to five different sweet potato varieties (Rongshu819, Quanshu17 , Guangshu214 , Fushu604 and PushuNo. 32) and tested the resistance of different sweet potato varieties. 【Result】 Stems and leaves damage loss rate and storage roots damage loss rate had been clearly about resistance indexes, five resistance levels (more sensitive, sensitive, resistance, medium resistance, greater resistance) were established. Damage indexes of vines and leaves were lighter than storage roots, the differences were not significant. Except Quanshu17 and Guangshu214 , damage indexes were significantly different between varieties. The average damage loss rate were 21. 17 (PushuNo. 32) , 38. 78 (Quanshu17) , 48. 00 (Guangshu214) and 70. 91 (Fushu604), damage loss rate of each variety weren't significant different between the two years. 【Conulusion】 By comparing with Rongshu819, Fushu604 was more sensitive, PushuNo. 32 was medium resistance, Quanshu17 and Guangshu214 were sensitive. The method adopted in research which could effectively detect the resistance of different sweet potato varieties. [ABSTRACT FROM AUTHOR]

Aims: The root cadmium (Cd) concentrations of sweet potato ( Ipomoea batatas [L.] Lam.) cultivars vary greatly. In this study, we explored the role of shoots and roots in Cd accumulation as well as the related underlying physiological mechanisms using the previously identified high-Cd cultivar X16 and low-Cd cultivar N88. Methods: We used the split-root technique and reciprocal grafting to determine the role of shoots and feeder roots in edible root Cd concentration. Two hydroponic experiments-one time-dependent and one dose-dependent-were also carried out to investigate the differences in the root-to-shoot Cd translocation between the two cultivars. Furthermore, we determined the influence of transpiration rate on Cd accumulation in the shoots and roots of the two cultivars using a hydroponic system. Results: The Cd accumulation in the shoots and edible roots of split-root sweet potatoes increased with the soil Cd concentration on either side; however, the feeder root Cd concentration was only related to the soil Cd level on the growth side, but not to that on the other side. The Cd concentrations in all the tissues of the grafts with X16 scion and N88 rootstock were higher than those of the non-grafted N88. Yet, the Cd concentrations in all the tissues of the grafts with N88 scion and X16 rootstock were lower than those in the non-grafted X16. Furthermore, X16 had a higher root-to-shoot Cd translocation and transpiration rate, which affected Cd translocation but not Cd uptake by the root. Conclusions: Cd was accumulated in the edible roots of sweet potato from both shoots and feeder roots. X16 had a higher ability of Cd translocation from the roots to the shoots via the xylem than N88. Therefore, the inter-cultivar variations in edible root Cd accumulation in sweet potato are related not only to Cd translocation from feeder to edible roots, but also to translocation from feeder roots to shoots. [ABSTRACT FROM AUTHOR]

It is shown for the first time how participatory variety demonstration (PVD) trials can establish modern varieties in informal seed systems in a developing country by targeting nodal multipliers occupying hub locations. A series of relatively few, small (each 36 m2) PVD trials was conducted over a period of 3 years in sweetpotato multipliers’ fields at three locations in Uganda; multipliers and farmers were encouraged to visit during crop growth and on field days; yields at final harvest and other traits considered important to multipliers and farmers were recorded. In the following dry season, the areas of the introduced varieties established in the lowland crops used by multipliers to conserve planting material were recorded. The two most popular varieties had a recorded area of about 1 ha each and were calculated to have increased sixfold annually from the trials; the next two occupied 0.5 ha each, confirming that the method is effective, cheap, and efficient. [ABSTRACT FROM PUBLISHER]

The root knot nematode, Meloidogyne is one of the most economically damaging plant parasitic nematode groups, and are widely distributed in Kenyan agro-ecosystems. The aim of this study was to determine the diversity of Meloidogyne species in Kenyan sweet potato fields and identify sweet potato varieties that exhibit resistance to M . incognita . Meloidogyne species were collected from Nyanza, Western, Eastern and Central Provinces of Kenya. Mitochondrial DNA was used to differentiate Meloidogyne species. The most common species in all sampled regions was M . incognita . Meloidogyne hapla was recorded for the first time in Kenyan sweet potato growing areas (Mosocho, Matayos, Teso South, Manyatta, and Nzaui sub-counties), while M . enterolobii was observed in Kiharu, Matayos and Mosocho sub-counties and a novel Meloidogyne sp. was identified in Kiharu sub-county. Seventy-two sweet potato varieties collected from both agricultural fields and research stations in Kenya were evaluated for resistance to M . incognita under greenhouse conditions in two separate trials. Known susceptible (Beauregard) and resistant (Tanzania) sweet potato varieties were included as controls. Responses of sweet potato varieties to M . incognita infection was assessed by the number of eggs present and level of galling on a scale of 1–5, where 0 = 0 galls and 5 ≥ 100 galls. The reproduction index (RI) was used to classify the varieties as resistant or susceptible. There was a significant difference (P < 0.001) in the number of eggs, GI and RI among the varieties tested. Forty nine sweet potato varieties were considered very resistant and may be used in breeding programs to incorporate resistance against M . incognita into commercial cultivars of sweet potato or to use them in crop rotation programmes for management of RKN. The results on Meloidogyne species diversity in Kenyan sweet potato fields will also be useful in nematode management programs. [ABSTRACT FROM AUTHOR]

BACKGROUND Increasing demand for sweet potato in regions with temperate climates has triggered interest in the development of new cultivars. Breeding of this crop should consider sensory characteristics in order to meet consumers' expectations. This requires the application of simple and cost-effective methodologies that allow quality evaluation from a sensory perspective. RESULTS With the objective of identifying the key sensory characteristics of different sweet potato genotypes, two commercial cultivars and seven clones were evaluated during three consecutive years using projective mapping by an untrained consumer panel. This methodology allowed the discrimination of the genotypes, identifying similarities and differences among groups based on sensory terms selected by the assessors. Genotypes were differentiated in terms of texture and flavor characteristics (firmness, moisture, smoothness, creaminess, flavor intensity, sweetness and bitterness). Materials for future crossings were identified. CONCLUSIONS The evaluation of the sensory characteristics of sweet potato clones and cultivars using projective mapping is a quick, cost-effective and reliable tool for the selection of new advanced sweet potato clones with superior sensory characteristics compared to the reference cultivars INIA Arapey and Cuarí. © 2016 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Sweetpotato is an important tuberous root crop rich in nutrients such as vitamins and carbohydrates, and can grow well in arid regions with less water consuming crop. The aim of this research was to evaluate the storage root yields, physiological, biochemical and morphological traits in sweetpotato cv. 'Japanese Yellow' subjected to polyethylene glycol (PEG)-induced water deficit. At harvest (4 months after planting) the number of storage roots per plant and storage root fresh weight in sweetpotato treated with 5% PEG (-0.54 MPa) in nutrient solution of hydroponic culture declined by 20.0% and 47.4% compared to the control without PEG, respectively. Leaf area and leaf dry weight significantly decreased by 85.6% and 95.3%, respectively when exposed to water deficit stress. Sucrose content (114.7 mg g-1 dry weight; DW) in storage roots of sweetpotato grown under PEG-induced water deficit conditions was enriched by 2.2 fold of control (52.5 mg g-1 DW) and was greater than in storage roots derived from soil culture (70.3 mg g-1 DW). Total soluble sugar in the root and storage root tissues was enriched and may play a key role as osmotic adjustment (OA) in PEG-induced water stressed plants. Free proline and sucrose contents were also dominated in the leaf tissues to maintain the leaf osmotic potential in water stressed plants. In addition, chlorophyll degradation, chlorophyll fluorescence diminution and stomatal closure were found in plants grown under PEG-induced water deficit conditions, leading to reduction in net photosynthetic rate (Pn) and subsequently lesser amounts of glucose and fructose contents in the leaf tissues. Sucrose and free proline in the roots of sweetpotato play a key role as major osmotic adjustment when subjected to PEG-induced water deficit condition. Basic knowledge gained from this research will further be investigated the drought defense mechanism in sweetpotato via osmoregulation system. [ABSTRACT FROM AUTHOR]

Near-infrared spectroscopy (NIRS) is an alternative analytical method that can be used to quantify protein content in sweetpotato. It is relatively cheaper and efficient than other methods. This study was conducted to develop NIRS-based models for quantifying protein content of sweetpotato for selection or wide-area production of recommended varieties. A pool of 104 sweetpotato varieties were sampled and roots scanned using NIR spectrometer. Calibration models were developed by subjecting spectral and reference datasets to partial least squares regression. Several pre-processing methods were investigated. Models that yielded the highest coefficient of determination (R 2 ), residual predictive deviation (RPD) and lowest root mean square error of calibration (RMSEC) and prediction (RMSEP) were selected. Optimal model performances were obtained using second derivative pre-processing, showing the highest values of R 2 v , RMSEP and RPD v of 0.98, 0.29, and 4.0, respectively. The regression analysis indicated that informative NIR bands for quantifying protein content of sweetpotatoes ranged between 1600 and 2200 nm. The results demonstrated that NIRS is capable of predicting protein content on sweetpotatoes, rapidly and accurately. Therefore, the NIRS model developed in this study may help to quantify protein composition of sweetpotato for rapid screening of germplasm in breeding programs with high throughput and accuracy. [ABSTRACT FROM AUTHOR]

Electrophysiological and behavioural studies coupled with field experiments were conducted to analyse the olfactory responses of sweetpotato weevil (SPW), Cylas formicarius Fab. to six varieties of sweetpotato, in order to understand how the olfactory system of the weevil distinguishes between volatiles from the susceptible and resistant varieties. Female SPW recorded significantly highest attraction (P < 0.01) towards 'Kishan' volatiles and lowest towards 'Gouri'. SPW infestation was highest in 'Kishan' (82.33%), whereas it was lowest in 'Gouri' (33.73%) at field level. A greater electrophysiological response was recorded by male and female SPW antenna to leaf and flower volatiles respectively. Males showed higher depolarization amplitude) and lesser recovery time compared to females, particularly to leaf volatiles. The comparative study of electroantennographic analysis, olfactometry and infestation data indicated that 'Kishan' is the most susceptible variety, attracting a large number of weevils; while 'Gouri', is the resistant variety. [ABSTRACT FROM AUTHOR]

The amount of genotypic and phenotypic variability that exists in a species is important for selection and initiating breeding programs. Yam bean is grown locally in tropical countries of the Americas and Asia for their tasty storage roots, which usually have low drymatter content. The crop was recently introduced in Uganda and other East and Central African countries to supplement iron (Fe) and protein content in diets. This study aimed to estimate genetic variability for root yield and quality traits among 26 yam bean accessions in Uganda. A randomized complete block design was used with two replications across two ecogeographical locations and two seasons during 2012 and 2013. Near-infrared reflectance spectroscopy (NIRS) was used to determine quality of storage root samples. Significant differences among genotypes were observed for all traits except root protein, zinc (Zn), and phosphorus contents. Genotypic variance components (σG²) were significant for storage root fresh yield (SRFY), storage root dry matter (SRDM), storage root dry yield (SRDY), vine yield (VNY), fresh biomass yield (FBY), and storage root starch (STA) and Fe contents. For traits with significant σG²; the broad sense heritability estimates ranged from 58.4% for SRDY to 83.6% for FBY; and phenotypic coefficients of variation were high for SRFY (66%), SRDY (53.3%), VNY (60.5%), and FBY (59%), but low to medium for SRDM (22.6%), STA (15.1%), and Fe (21.3%). Similarly, the genotypic coefficients of variation were high for SRFY (56.7%), SRDY (53.3%), VNY (55%), and FBY (53.9%); and low for SRDM(20%), STA (12.4%), and Fe (17.8%). There were strong positive correlations between SRFY and both SRDY (r = 0.926) and FBY (r = 0.962), but low-to-moderate correlations among quality traits. It should be possible to breed for high dry matter yam beans by using low dry matter accessions due to the observed genetic variation (σG² = 9.3%2), which is important if the high dry matter Pachyrhizus tuberosus accessions (known as chuin) from Peru cannot be accessed. This study indicated substantial genetic variation for yield and quality traits in yam bean, demonstrating potential for adaptability to growing conditions and consumer needs in East and Central Africa and for genetic improvement through selection. [ABSTRACT FROM AUTHOR]

A 14.4 × 86.0 × 70.0 cm mud evaporative cooler was designed and constructed for the storage of sweet potato roots to evaluate its performance in storing orange fleshed sweet potato variety (Apomuden) roots. The investigation lasted for 14 weeks, from November 2014 to February, 2015. The dry bulb (Tdb) and wet bulb temperatures (Twb) for the ambient storage ranged between 27.600C to 26.900C and 22.500C to 20.100C respectively with their corresponding RH of 64.00%, 77.00% respectively, while Tdb and Twb within the cooler ranged between 25.940C to 24.860C and 21.940C to 20.610C with corresponding R.H of 89.00% to 92.00% respectively. The efficiency of the constructed evaporative cooler was 87.17%. From an initial weight of 2000 g, roots weight decreased to 1298.3 g during the storage period, while the weight loss within the cooler was from 2000 g to 1570.65 g over the same period. Also, the moisture content of the roots stored under ambient conditions declined from 68.9% to 48.35%. Roots stored in the evaporative cooler declined from 68.9% to 60.80%. As mc decreased from 68.9% to 48.35%, energy content increased from an initial of 501 to 858.677 kJ/100g under ambient storage while in the evaporative cooler, as mc declined, from 68.9% to 60.8%, energy content increased from an initial of 501.518 to 642.296 kJ/100g. The evaporative cooler maintained the quality of the sweet potato roots by fourteen weeks while those stored in the ambient storage lasted for eight weeks. [ABSTRACT FROM AUTHOR]

In southern Africa, sweetpotato improvement through genetic engineering has been hampered by the lack of regeneration protocols of the most famous cultivars. The aim of this study was to develop an efficient and reproducible regeneration protocol of the sweetpotato cv. Brondal that is widely grown in Zimbabwe. In the regeneration study, the parameters for optimisation were petiole orientation (horizontal, vertical or inverted), Cytokinin type (Zeatin, Kinetin or Thidiazuron) and Cytokinin concentration (0.1 mg L − 1 , 0.2 mg L − 1 , or 0.4 mg L − 1 ), making a total of 27 treatments. In the first experiment, petioles were subjected to all 27 treatments to assess capacity to initiate root formation within three weeks. In the second experiment, only the effects of Cytokinin type and concentration were investigated to determine influence on root number, root length and shoot production. There was a significant (p = 0.031) interaction between orientation type and Cytokinin type, with the inverted orientation type producing the most number of roots (five roots/petiole) than the horizontal (three roots/petiole) or vertical (three roots/petiole) orientation types, regardless of the Cytokinin used. There was a significant (p = 0.01) interaction between Cytokinin type and Cytokinin concentration, with the Zeatin hormone consistently producing the most number of roots (five roots/petiole) than either Kinetin or Thidiazuron (average of three roots/petiole) regardless of the Cytokinin concentration used. Where root length was concerned, there was generally no significant difference between treatments (all treatments producing roots with lengths ranging from 0.1 to 7.0 mm) except for Kinetin 0.4 mg L − 1 which consistently produced roots ranging 17–25 mm in length. For shoot production, all Zeatin had relatively higher (10.6%) shoot regeneration frequencies that either the Kinetin (3.3%) or Thidiazuron (0%). The greater the number of roots produced by a petiole, the greater the likelihood of shoot development on that petiole. In conclusion, the best treatments for root and shoot regeneration proved to be Murashige and Skoog media supplemented with Zeatin at 0.2 mg L − 1 with petioles oriented in the inverted position. [ABSTRACT FROM AUTHOR]

The article focuses on a research related to cultivars of sweet potatoes adapted to local farmer and consumer needs in Africa. It mentions breeding objectives like high storage root and vine yield, high beta-carotene levels and drought adaptation. It also mentions that several sweet potato bred germplasm are kept in the CIP breeding nursery.

Vitamin A deficiency (VAD) is of public health significance in the developing world. In spite of extensive promotion of orange-fleshed sweetpotato(Ipomoea batatas)varieties (OFSPs), they are poorly utilized in Ghana because of their low dry matter and high sugar content. The objective of this study was to develop farmer- and consumer-preferred beta-carotene-rich varieties to increase OFSP utilization in Ghana and beyond. One released variety in Ghana (Apomuden) and four other varieties which are introductions (Beauregard, Resisto, CIP 442850, and CIP 443035) were used as parents. They were crossed using the full diallel mating design. There was significant genetic variation for the traits and among the F1hybrids. Significant positive and negative heterosis was found, but the levels were not adequate for the development of non-sweet, high dry matter, and high beta-carotene-rich varieties. Twenty-one F1hybrids that had comparable beta-carotene content and storage root yield but lower sugar content than the only released high-beta-carotene variety in Ghana were identified for further testing for potential release. [ABSTRACT FROM PUBLISHER]

Proximate composition (moisture, protein, starch, amylose, total dietary fibre, Brix degree, fat, ash, ascorbic acid, phenolic compounds, acidity and pH), minerals (Na, K, Ca, Mg) and trace elements (Fe, Cu, Mn, Zn) were determined in 30 cultivars of sweet potato from the Canary Islands (Spain). There were significant differences between the sweet potato cultivars for all the parameters studied; in addition, both the island of production and the cultivation cycle showed a noteworthy influence on the mineral and trace element composition of the tubers. It is worth mentioning that the consumption of sweet potatoes contributes relatively high intake levels of vitamin C, phenolic compounds and mineral and trace elements (K, Mg, Ca, Mn, Fe and Cu). Application of multidimensional scaling (MDS) correctly classified the sweet potato cultivars according to the island of production and maturation cycle. [ABSTRACT FROM AUTHOR]

Purple sweet potato ( Ipomoea batatas L.) is rich in anthocyanin pigments, which are valuable constituents of the human diet. Techniques to identify and quantify anthocyanins and their antioxidant potential are desirable for cultivar selection and breeding. In this study, we performed a quantitative and qualitative chemical analysis of 30 purple sweet potato (PSP) cultivars, using various assays to measure reducing power radical-scavenging activities, and linoleic acid autoxidation inhibition activity. Grey relational analysis (GRA) was applied to establish relationships between the antioxidant activities and the chemical fingerprints, in order to identify key bioactive compounds. The results indicated that four peonidin-based anthocyanins and three cyanidin-based anthocyanins make significant contributions to antioxidant activity. We conclude that the analytical pipeline described here represents an effective method to evaluate the antioxidant potential of, and the contributing compounds present in, PSP cultivars. This approach may be used to guide future breeding strategies. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Plant Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The sweet potato (Ipomoea batatas L.) belongs to very important crops from aspect of its world production. It is grown in large areas in Asia, on the contrary, sweet potato production in Europe presents minimal part of its total world rate. The sweet potato is less-known crop, grown only on small area in home gardens in Slovak Republic. Tubers of sweet potato are characterized by anti-diabetic, anti-oxidant and anti-proliferative properties due to the presence of valuable healthpromoting components, such as carotenoids or vitamin C. The main objective of study was testing of sweet potato growing in conditions of southern Slovak Republic with focus on quantity and quality of its yield. The field trial was realised on land of the Slovak University of Agriculture in Nitra in 2015. Within trial, effect of cultivar and mulching on the selected quantitative (average tuber weight; yield per plant; yield in t.ha-1) and qualitative (total carotenoids; vitamin C) parameters were tested. One certified cultivar of sweet potato 'Beauregard' was used as a comparative cultivar. Other two cultivars were marked according to the market place at which were purchased and sequentially used for seedling preparation. Tubers of first un-known cultivar were purchased in the Serbian market (marked as 'Serbian'). Tubers of next sweet potato cultivar were purchased on the market in Zagreb (marked as 'Zagrebian'). Outplating of sweet potato seedlings were realised on the 19th May 2015. The sweet potato was grown by hillock system. Each cultivar was planted in two variants (rows): nonmulching (bare soil) and mulching by black non-woven textile. All variants were divided to three replications with 6 plants. Difference between rows was 1.20 m and seedlings were planted in distance of 0.30 m in row. The harvested tubers were classified in two size classes: >150 g (marketable yield) and <150 g (non-marketable yield). Total carotenoid content was determined spectrophotometrically. The vitamin C content was measured chromatographically (HPLC). The highest values of average tuber weight, yield per plant and total yield (t.ha-1) were found in cultivar 'Serbian'. Statistical analysis showed statistically significant difference in all yield quantitative parameters of cultivar 'Serbian' against cultivars 'Beauregard' and 'Zagrebian'. The highest content of total carotenoids was determined in cultivar 'Serbian' (99.52 mg.kg-1 fresh weight) with orange-creme flesh color, followed by cultivar 'Beauregard' (94.78 mg.kg-1) with orange flesh color and cultivar 'Zagrebian' (28.79 mg.kg-1) with yellow-creme flesh color. Differences among all cultivars were showed as statistically significant. The highest vitamin C content was detected in tubers of cultivar 'Serbian' (155.70 mg.kg-1), followed by cultivar 'Beauregard' (154.37 mg.kg-1) and cultivar 'Zagrebian' (146.33 mg.kg-1). Statistical analysis confirmed differences among cultivars as statistically non-significant. The mulching of sweet potato plants had statistically significant impact to all quantitative and qualitative characteristics of sweet potato. The application of black non-woven textile resulted in increase of average tuber weight, tuber yield and vitamin C content in sweet potato tubers. On the contrary, higher total carotenoid content was found in non-mulching variant compared to the variant with mulching. [ABSTRACT FROM AUTHOR]

Sweet potato, Ipomoea batatas (L.) Lam., is an important food crop worldwide. The orange-fleshed sweet potato is considered to be an important source of beta-carotene. In this study, the transcriptome profiles of an orange-fleshed sweet potato cultivar “Weiduoli” and its mutant “HVB-3” with high carotenoid content were determined by using the high-throughput sequencing technology. A total of 13,767,387 and 9,837,090 high-quality reads were produced from Weiduoli and HVB-3, respectively. These reads were de novo assembled into 58,277 transcripts and 35,909 unigenes with an average length of 596 bp and 533 bp, respectively. In all, 874 differentially expressed genes (DEGs) were obtained between Weiduoli and HVB-3, 401 of which were upregulated and 473 were downregulated in HVB-3 compared to Weiduoli. Of the 697 DEGs annotated, 316 DEGs had GO terms and 62 DEGs were mapped onto 50 pathways. The 22 DEGs and 31 transcription factors involved in carotenoid biosynthesis were identified between Weiduoli and HVB-3. In addition, 1,725 SSR markers were detected. This study provides the genomic resources for discovering the genes involved in carotenoid biosynthesis of sweet potato and other plants. [ABSTRACT FROM AUTHOR]