Sweet Potato Cultivars Research Articles

Adaptation of recently released improved orange flesh sweet potato (Ipomoea batatas L.) varieties in Southwestern Ethiopia

Most sweet potato varieties currently grown by farmers are poorly adapted, have low root yields, less nutritive and white fleshed which have no beta carotene, a precursor to vitamin “A”. However, among the cheapest and richest sources of vitamin A; orange fleshed sweet potato varieties were rich in beta carotene are well accepted by young children. Hence the aim of this research project was conducted to evaluate the adaptability and performance of improved orange-fleshed sweet potato varieties on yield and other yield related traits during the 2020 main cropping season in southwest Ethiopia. The varieties used were Tulla, Kulfo, Guntutie, Vita, Kabode, Alamura and Dilla. The experiment was carried out using a randomized block design with three replications. The analysis of variance over locations depicted significant differences (p ≤0.05) among varieties for most of the studied traits. In this study, Alamura (31.42 t ha-1) and Dilla (27.8 t ha-1) varieties give a high yield among seven evaluated orange-fleshed sweet potato varieties. Based on farmer test preference, the first and second rank of test preference was recorded from Alamura and Dilla variety. Therefore, by considering both farmer’s test preference and the yield potential of the variety, Alamura and Dilla were selected as high yields and have the best test preference. Therefore, to fill the gap vitamin “A” deficiency at the community level Alamura and Dilla were selected as the best orange fleshed variety that has the best test preference with the highest yield in the humid tropics of Southwestern Ethiopia and these two varieties were recommended for production. Finally, since the result of this finding was based on data gathered from two locations and only one cropping season to test adaptability. So, one more additional season evaluation is necessary and also further studies are required to generate more reliable information on performance, nutrition and resistance to disease. Int. J. Agril. Res. Innov. Tech. 12(2): 111-116, December 2022

Supplemental lighting spectrum impact on sweet potato cutting production and rooting

AbstractLight is an important factor in plant growth and morphology of sweet potato (Ipomoea batatas L. Lam). This study explored the impact of supplemental lighting provided by three commercially available units on a stock plant cutting production and cutting rooting of two sweet potato cultivars ‘Covington’ and ‘Beauregard’. In experiment one, stock plants were grown under one of four lighting conditions, no supplemental light, high blue light emitting diode (LED), low blue LED, or halogen. Cuttings were collected twice a week for 5 wk and the total weekly cutting number and cutting caliper per plant were recorded. During this experiment plants grown under supplemental lighting exhibited significantly greater weekly total cutting numbers after 2 wk of growth when compared with those that were not exposed to supplemental lighting. In experiment two, cuttings were rooted under the same four light treatments and sampled on Days 7, 14, and 21 in which the cutting height, root weight, and shoot weight were recorded. On Day 21 Covington plants grown under low blue and halogen supplemental lighting exhibited significantly greater root dry weight when compared with those that did not receive supplemental lighting. However, no differences in rooting were observed for Beauregard. These results demonstrate that supplemental light increases stock plant growth regardless of the three commercially available light spectrums examined when compared with no supplemental light. This suggests that increasing the daily light integral (DLI) has a larger impact on plant growth than the spectrum of the commercially available lights that were examined.

Recent Progress in Breeding for Beta-Carotene, Dry Matter Content and Sugar in Sweet potato [Ipomoea Batatas (L.) Lam]-A Review

In several developing countries, root and tuber crops play a crucial role in food security as well as in agriculture. Based on production and consumption, sweet potato [Ipomoea batatas (L.) Lam] plays a significant role after potato among the root and tuber crops. Today, sweet potato breeding program focus on multiple purposes. There are four sweet potato breeding platforms (three in Africa) and in SSA there are four breeding centers (three in West Africa). High levels of β‐carotene, phenolics, anthocyanins, vitamins, fiber, dietary, minerals, and other bioactive compounds content depends on the flesh color of sweet potatoes. The orange‐fleshed sweet potato types contain high β‐carotene levels and low dry matter content. White‐cream fleshed color varieties have high dry matter (>30%). The purple‐fleshed sweet potato varieties with attractive color and high anthocyanin content are the most preferred in Asia. Sweet potato with low in sweetness and higher dry matter (28–30%) are the specially of most parts of sub-Saharan Africa. Consuming β‐carotene leads as a viable long‐term food‐based strategy for combating the deficiency vitamin A in the world. The sweet potato dry matter content up of 80-90% carbohydrates and exists in the form of starch and sugars non-starch polysaccharides. The primary contributors to the taste of the sweet potato are sugars and organic acids. The strong flavor and high levels of sweetness may have affected the popularity of sweet potato as a staple food. Due of the negative correlation between traits, breeding for high B-carotene and dry matter with low sugar in one variety has remained a challenge, although it was reported that recurrent mass selection should be possible to accumulate favorable alleles so that progress can be made over.

Comprehensive Evaluation of Raw Eating Quality in 81 Sweet Potato (Ipomoea batatas (L.) Lam) Varieties.

The raw eating quality of sweet potato is complex. As consumers start paying more attention to the raw eating quality of tuberous roots in sweet potato, the evaluation of the raw eating quality of sweet potato is becoming an important issue. Therefore, we measured 16 quality indicators in 81 varieties of sweet potato. It was found that these 16 quality traits had different coefficients of variation (C.V.). Among them, the C.V. of fructose, glucose, and adhesiveness were the largest: 87.95%, 87.43% and 55.09%, respectively. The cluster analysis method was used to define six categories of the different tuberous roots of sweet potato. Group I, III, and IV had a stronger hardness and higher starch and cellulose content. Groups II, V, and VI were softer, with a high moisture and soluble sugar content. The principal component analysis method was used to comprehensively evaluate 16 quality indicators of 81 sweet potato varieties. It was found that Futian1, Taishu14, and Nanshu022 are good varieties in terms of raw eating quality. These varieties have low hardness, high adhesiveness in texture, high soluble sugar content, and low starch and cellulose. Future research should focus on improving the raw eating quality of sweet potato by reducing hardness, starch, and cellulose, while increasing adhesiveness, soluble sugar, and moisture content.

Sweetpotato cultivars responses to interactive effects of warming, drought, and elevated carbon dioxide.

Plants are sensitive to changes projected in climates, such as elevated carbon dioxide (eCO2), high temperature (T), and drought stress (DS), which affect crop growth, development, and yield. These stresses, either alone or in combination, affect all aspects of sweetpotato plant growth and development, including storage root development and yield. We tested three sweetpotato cultivars (Beauregard, Hatteras, and LA1188) responses to eight treatments (Control, DS, T, eCO2, DS + T, T + eCO2, DS + eCO2, DS + T + eCO2). All treatments were imposed 36days after transplanting (DAP) and continued for 47days. Treatments substantially affected gas exchange, photosynthetic pigments, growth, and storage root components. Cultivars differed considerably for many of the measured parameters. The most significant negative impact of DS was recorded for the shoot and root weights. The combination of DS + T had a significant negative effect on storage root parameters. eCO2 alleviated some of the damaging effects of DS and high T in sweetpotato. For instance, eCO2 alone or combined with DS increased the storage root weights by 22% or 42% across all three cultivars, respectively. Based on the stress response index, cultivar "Hatteras" was most tolerant to individual and interactive stresses, and "LA 1188" was sensitive. Our findings suggest that eCO2 negates the negative impact of T or DS on the growth and yield of sweetpotato. We identified a set of individual and interactive stress-tolerant traits that can help select stress cultivars or breed new lines for future environments.

Histological studies on the relationship between the low seed set and abnormal embryo sacs in sweet potato, Ipomoea batatas (L.) Lam.

This study aimed to investigate the relationship between low seed set and abnormal embryo sacs lacking normal female organs, such as one egg cell, two assistant cells, and two polar nuclei, in Ipomoea trifida, which is closely related to sweet potato, and sweet potato cultivars and lines, through histological analysis of their ovaries on flowering day. Ovaries of diploid, tetraploid, and hexaploid lines of I. trifida each had four ovules, except for some hexaploid lines with five or six ovules. Almost all sweet potato cultivars and lines had four ovules per ovary, although some sib-cross lines had two or three ovules. The number of ovules per ovary did not have direct effects on low seed set. The frequency of abnormal embryo sac increased with polyploidy in I. trifida. However, it varied among different sweet potato cultivars and lines. Moreover, the variation in abnormal embryo sacs occurred at an earlier stage of gametogenesis (type A) in the tetraploid and hexaploid plants of I. trifida and sweet potato cultivars and lines. These findings suggest that the high frequency of abnormal embryo sacs is a primary cause of low seed set in sweet potato and that it is closely related to the decline in seed propagation that occurs in the evolution process of sweet potato.

Sabor e cor: ‘IAC 134 AL01’, primeira cultivar de batata-doce de polpa alaranjada do Instituto Agronômico de Campinas

ABSTRACT The sweet potato cultivar ‘IAC 134 AL01’ has tuberous roots with high β-carotene content, with the fresh pulp having an intermediate orange colour (based on international descriptors for the crop), which turns bright orange after cooking, and a mildly sweet taste. These roots have a long-irregular shape, red skin and are of medium size, weighing, on average, 300 g and measuring 14 x 6 cm. The first biofortified sweet potato cultivar of the Campinas Agronomic Institute reaches an average yield of 43.9 t/ha and is recommended for planting in the state of São Paulo to supply the domestic market and for export.

Development of a multicriteria decision-making model for evaluating hybrid offspring in the sweetpotato (Ipomoea batatas L.) breeding process.

Sweetpotato variety breeding is always a long process. Screening of hybrid offspring is dominated by empirical judgment in this process. Data analysis and decision fatigue have been troubling breeders. In recent years, the low-efficiency screening mode has been unable to meet the requirements of sweetpotato germplasm innovation. Therefore, it is necessary to construct a high-efficiency method that can screen germplasms for different usages, for mining elite genotypes, and to create dedicated sweetpotato varieties. In this article, the multicriteria decision-making (MCDM) model was constructed based on six agronomic traits, including fresh root yield, vine length, vine diameter, branch number, root number and the spatial distribution of storage roots, and five quality traits, including dry matter content, marketable root yield, uniformity of roots, starch content and the edible quality score. Among these, the edible quality score was calculated by using fuzzy comprehensive evaluation to integrate the sensory scores of color, odor, sweetness, stickiness and fibrous taste. The MCDM model was compared with the traditional screening method via an evaluation in 25 sweetpotato materials. The interference of subjective factors on the evaluation results was significantly reduced. The MCDM model is more overall, more accurate and faster than the traditional screening method in the selection of elite sweetpotato materials. It could be programmed to serve the breeders in combination with the traditional screening method.

Chromatographic printed array strip (C-PAS) method for cultivar-specific identification of sweetpotato cultivars 'Beniharuka' and 'Fukumurasaki'.

Sweetpotato (Ipomoea batatas) cultivars grown in Japan are highly valued for their excellent sweetness, high quality, and good texture. The export volume of sweetpotato from Japan has been rising rapidly, with a 10-fold increase on a weight basis over the last 10 years. However, since sweetpotato is propagated vegetatively from storage roots, it is easy to cultivate and propagate this crop, prompting concerns that Japanese sweetpotato cultivars/lines are being exported overseas, cultivated without permission, or reimported. Therefore, a rapid and accurate cultivar identification methodology is needed. In this study, we comprehensively analyzed the insertion sites of Cl8 retrotransposon to develop a cultivar identification technique for the Japanese cultivars 'Beniharuka' and 'Fukumurasaki'. These two cultivars were successfully distinguished from other cultivars using a minimum of two marker sets. Using the chromatographic printed array strip (C-PAS) method for DNA signal detection, 'Beniharuka' and 'Fukumurasaki' can be precisely identified using a single strip of chromatographic paper based on multiplex DNA signals derived from the amplicons of the Cl8 insertion sites. Since this method can detect DNA signals in only ~15 minutes, we expect that our method will facilitate rapid, reliable, and convenient cultivar discrimination for on-site inspection of sweetpotato.

Susceptibility of Sweet Potato Varieties to Meloidogyne incognita and Use of Effective Microorganisms and Compost Manure for the Disease Management

Susceptibility of Sweet Potato Varieties to Meloidogyne incognita and Use of Effective Microorganisms and Compost Manure for the Disease Management

Study on effect of various levels of nitrogen on growth, yield and quality of sweet potato varieties [<em>Ipomoea batatas </em>(L) Lam.

Study on effect of various levels of nitrogen on growth, yield and quality of sweet potato varieties [<em>Ipomoea batatas </em>(L) Lam.

Farmers’ selection criteria for sweet potato varieties in Benin: An application of Best-Worst Scaling

Summary Integrating farmers’ preferences into the breeding and dissemination of new genotypes is a effective approach to enhance their successful adoption by farmers. In the case of sweet potato, a staple crop in many parts of West Africa, there is a need for more research on the selection criteria used by farmers when choosing which varieties to grow. This study aims to highlight farmers’ selection criteria for sweet potato varieties in the main production areas in Benin. A total of 480 farmers from the top three sweet potato production areas were surveyed. The relative importance of various traits for sweet potato farmers was evaluated using best-worst scaling methods. Latent class analysis was applied to find groups of farmers with similar preferences. Best-Worst Scaling analysis revealed that high root yield, root size, marketability, and early maturing were the most important variety selection criteria. Latent class analysis revealed three farmers’ groups referred to as ‘Yield potential’, ‘Market value’, and ‘Plant resilience’ classes. ‘Yield potential’ farmers were more likely to be from Atlantique and Alibori departments; they significantly committed more acreage to sweet potato production. The ‘Market value’ farmers highlighted the variety of root size and commercial value as the main selection criteria and consisted of farmers with primary education levels from the Ouémé department. ‘Plant resilience’ refers to a group of Alibori farmers who prioritize environmental issues and primarily grow sweet potatoes for self-consumption. Our findings shed light on farmers’ preferences and suggested that heterogeneity in sweet potato selection criteria was highly influenced by various socio-economic factors and location.

Popularization of Medium Maturing Orange Fleshed Sweet Potato (OFSP) Variety (Alamura) and on Farm Evaluation of Its Root Yield Performance at Halaba Zone, Weira District, SNNPR, Ethiopia

Orange-fleshed sweet potatoes are one of the most important root crops for their high -carotene content, which protects against vitamin A deficiency. But in the most rural areas of the country, there is a serious health problem related to vitamin A deficiency. The associated causes of inadequate intake and production of this crop are lower adoption, weak extension support, and inaccessibility of improved varieties. For that, demonstration of a recent variety of sweet potato is a necessary action. Hence, it improves the adoption rate, creates awareness, and contributes to food and nutritional security. Accordingly, two farmer training centers and ten farmers were purposely selected to conduct the demonstration. The variety "Kulfo" was used for the experiment by using a 10m x 20m plot size for each variety. Evaluations were conducted during the mid-maturity stage, through the field day, and field visits with concerned stakeholders, beneficiaries, and surrounding farmers. Based on the result, the yield of the new variety and the standard check are 22.5 tons/ha and 10.5 tons/ha, respectively. The result shows that the yield of the improved variety has a 114.3 percent yield advantage compared to the standard check. In addition, the result of cost-benefit analysis reveals that the new variety has 65250.1 Ethiopian Birr more return than the standard check and is ranked by farmers by its disease resistance, taste, and productivity. Therefore, the new variety is recommended for further scale up in the Halaba zone and other similar agro-ecologies, and agricultural extension personnel will be encouraged to facilitate communication among farmers-researchers and vein multiple cooperatives.

PENGARUH INTERAKSI ANTARA PEMBERIAN BIOFOSFAT DENGAN PENGGUNAAN KULTIVATOR LOKAL UBI JALAR TERHADAP PERTUMBUHAN HASIL DAN KANDUNGAN GULA TANAMAN UBI JALAR

This study aims to examine the effect of the interaction between the administration of biophosphate and the use of local Jakar potato cultivars on the growth, yield and sugar content of sweet potato plants. The research method uses (RAK) 4 times. The 1st factor was Biophosphate (B), consisting of two levels: b1 (100 kg/ha biophosphate) and b2 (200 kg/ha biophosphate). The second factor was Sweet Potato Cultivar (K), consisting of three levels: k1 (cilembu), k2 (maja) and k3 (brass and white). Differences in treatment means were tested using Duncan's multiple range test at the 5% level. The results showed that bophosphate and sweet potato cultivars had no interaction effect. Phosphate administration did not have a different effect on all growth and yield variables of sweet potato plants. The use of cultivars had no different effect on growth, yield and sugar content.

Influence of Mineral Treatment, Plant Growth Regulators and Artificial Light on the Growth of Jewel Sweet Potato (Ipomoea batatas Lam. cv. Jewel) In Vitro

Sweet potato (Ipomoea batatas (L.) Lam), a member of the bindweed family (Convolvulaceae Juss.), is well known for its food, medicinal, and industrial values. It is estimated that more than 7000 sweet potato cultivars have been bred to date. Jewel sweet potato (I. batatas Lam cv. Jewel) is one of the most popular cultivars of sweet potato grown today because of its high nutritional value, delicious taste, and is suitable for all processing methods. However, little is known about the micropropagation of jewel sweet potato. The purpose of this paper was to study the effect of three important factors, including culture medium, plant growth regulators (PGRs), and artificial light sources, on the induction, proliferation, and growth of in vitro I. batatas 'Jewel' shoots obtained from the axillary bud and shoot tip explants. The different Murashige and Skoog (MS) salt levels (33%, 50%, 100%, and 150%) were used to study the influence of mineral treatment. To assess the influence of PGRs, we used 0.5 mg/L indole-3-acetic acid (IAA) combined with various cytokinins, including 0.5-2.0 mg/L 6-benzylaminopurine (BAP), 0.5-2.0 mg/L kinetin (Kn), and 0.1-1.0 mg/L thidiazuron (TDZ). On the other hand, the in vitro shoots were cultivated in a light room with different lighting conditions. Three lighting treatments (differences in the ratio between the red (R) and blue (B) spectra) were used. Research results have shown that the medium containing 50% MS salt concentration supplemented with 0.5 mg/L BAP or 0.5 mg/L Kn combined with 0.5 mg/L IAA was the most suitable for induction, proliferation, and growth of in vitro jewel sweet potato shoots. On the other hand, stem pieces bearing the axillary buds' explants were determined to be suitable for the shoot induction. Using artificial light with different blue/red ratios also had a significant effect on the growth of explants and stimulates shoot or root formation.

Growth, yield and quality of selected sweet potato (Ipomoea batatas [l.] Lam.), lines under varying soil moisture conditions

Sweet Potato (Ipomoea batatas [L.] has increasing potential as a food security crop in Kenya. However, its’ production is relatively low compared to its potential production which is attributed to drought conditions alongside use of local landrace cultivars that are quite low yielding. A study was conducted at Meru University of Science and Technology in Kenya in 2020-2021 to assess the performance of selected improved sweet potato lines under varied watering regimes. Two selected sweet potato varieties were used; CIP 106988.1 (Naspot13) and CIP 112286.1(Margarette), and a farmer-preferred variety Kemb-10. The varieties were subjected to three watering regimes (i) Severe stress (SS), 4 WAE (ii) Moderate Stress (MS), 9 WAE and (iii) well watered to maturity. A randomized complete block design in a split plot, with water treatment as the main plot and varieties as subplot with 3 replicates was used. There was no significant interaction between moisture treatments and varieties. Water treatments significantly (p≤0.05) affected vine length, number of leaves and tuber yield. Plants under severe stress had significantly lower vine length, branches and leaves. Under Moderate stress 9 WAE, plants experienced significant reduction in vine length, leaves and branches compared to the well watered. However, this reduction was less compared to severe stress. The reduced vine length and tuber yield is attributed to reduced cell division, elongation and assimilates partitioning. Tuber numbers correlated with leaves (r = 0.63*, 0.74*), and vine length (r = 0.62*, 0.76*). This positive correlation implies that if drought significantly reduces number of leaves and vine length, it reduces tuber yield indicating effect of drought on tuber yield can be estimated by measuring tuber length and number of leaves. Based on findings, ensuring the crop obtains enough moisture during the first nine weeks after planting is recommendable whereas Naspot13 is suitable for the area considering its higher productivity.

Comparative Metabolomic and Transcriptomic Analyses of Phytochemicals in Two Elite Sweet Potato Cultivars for Table Use.

To elucidate nutritional components in sweet potato cultivars for table use and to compare the phytochemicals of cultivars from different countries, 'Kokei No. 14' and 'Xinxiang' were selected. The physiological parameters and metabolites were determined using the colorimetric method and widely targeted metabolomics, respectively. Transcriptomic analysis was performed to explain the mechanism that resulted in phytochemical differences. 'Xinxiang' showed higher flavonoid and carotenoid contents. Metabolomics showed five upregulated flavonoids. Two essential amino acids (EAAs) and one conditionally essential amino acid (CEAA) were upregulated, whereas four EAAs and two CEAAs were downregulated. Unlike lipids, in which only one of thirty-nine was upregulated, nine of twenty-seven differentially accumulated phenolic acids were upregulated. Three of the eleven different alkaloids were upregulated. Similarly, eight organic acids were downregulated, with two upregulated. In addition, three of the seventeen different saccharides and alcohols were upregulated. In 'other metabolites,' unlike vitamin C, 6'-O-Glucosylaucubin and pantetheine were downregulated. The differentially accumulated metabolites were enriched to pathways of the biosynthesis of secondary metabolites, ABC transporters, and tyrosine metabolism, whereas the differentially expressed genes were mainly concentrated in the metabolic pathway, secondary metabolite biosynthesis, and transmembrane transport functions. These results will optimize the sweet potato market structure and enable a healthier diet for East Asian residents.

Orange Fleshed Sweet Potato Response to Filter Cake and Macadamia Husk Compost in Two Agroecologies of KwaZulu-Natal Province, South Africa

Field experiments were carried out during the summer/autumn (first trial) and winter/spring (second trial) seasons of 2019 and 2021 in the Dlangubo, Ngwelezane, and Mtubatuba areas of KwaZulu-Natal Province of South Africa to study the drought amelioration effects and impact of two locally available organic wastes (filter cake—a residue derived from sugar cane filtration (FC) and macadamia husk compost (MHC)) on the productivity and physiological responses of four orange-fleshed sweet potato cultivars (Beauregard cv., Impilo, W-119 and 199062.1). The effects of FC and MHC were compared with that of inorganic fertilizer (IF) [2:3:2 (30)], FC + IF, MHC + IF, and the control. The soil amendments were applied in the first trials only. Climatic data such as humidity, temperature, and rainfall were taken via remote sensing. The results of the first trial indicated that filter cake and IF significantly performed better than MHC. The strength of filter cake may be attributable to its rich array of mineral nutrients such as calcium, magnesium, potassium, sodium, zinc, copper, manganese, iron, and phosphorus. The limited performance of MHC may be attributable to its ability to hold water. Furthermore, a positive correction occurred between the yield of the test orange-fleshed sweet potato (OFSP) cultivars, rainfall, and vegetation indices (normalized difference vegetation index, enhanced vegetation index, and normalized difference water index) investigated in the study. In season two, IF treatment did not have any significant effect on the growth and productivity of any of the tested sweet potato cultivars, but, FC, FC + IF, and MHC treatments largely maintained their performances. In conclusion, the use of FC is highly recommended in the production of the test OFSP cultivars. Furthermore, the study indicates that both FC and MHC may not only supply the needed plant nutrients but has the capacity to reduce the impact of drought on the growth of the test cultivars. These findings are of great value to farmers, especially the resource-poor ones.

Genetic Diversity Assessment of Sweetpotato Germplasm in China Using InDel Markers

Sweetpotato (Ipomoea batatas (L.) Lam.), whose roots are rich in starch, is widely grown around the world and plays a prominent role in ensuring food security. At present, there are no reports on the genetic diversity of sweetpotato germplasm revealed by InDel markers. In this study, we developed a set of 30 InDel markers to evaluate the genetic diversity and relationships of 240 accessions, comprising 77 landraces, 80 introduced accessions, 82 improved varieties released in China, and a diploid wild relative Ipomoea trifida. A total of 94 reliable loci were obtained, with a mean of 3.13 loci per primer, and the PIC value ranged from 0.143 to 0.821. The whole population could be divided into three sub-populations according to a structure analysis based on the Bayesian model, which was consistent with the results of principal component analysis (PCA). A neighbor-joining tree was constructed based on Nei’s genetic distance ranging from 0 to 0.556 and discriminated the panel of the population into three main groups (Ⅰ, Ⅱ, Ⅲ). Group Ⅲ was further split into seven subgroups (ⅢA–ⅢG). The clustering pattern of the 240 accessions was unrelated to their geographic origins. Most of the accessions, whether landraces, improved varieties released in China or introduced germplasm, were mixed, which revealed the high level of genetic similarity among accessions from different regions. There was little difference in the level of genetic diversity between landraces and improved varieties, which was probably due to the exchange and utilization of accessions from different regions. More efforts should be made to collect and utilize sweetpotato germplasm resources and further broaden the genetic basis of sweetpotato cultivars.

Influence of lightculture on obtaining planting material of Ipomoea batatas (L.) in vitro

The current article presents the results of the influence of lighting conditions on the morphogenetic potential of Ipomoea batatas (L.) microcuttings in vitro. The studied objects were 4 sweet potato cultivars - Jewel, Purple, Porto Rico, Vinnitsa pink. Microcuttings of I. batatas were cultivated in vitro. We used nutrient medium with mineral salts (according to the prescription of Murashige and Skoog (MS)) and medium only with distilled water (without mineral salts). All nutrient media contained sucrose 2% and agar 0.7%. Hormones were not added to the nutrient media. We studied the influence of the different red (R) and far red (FR) ratios, as well as the red and blue light spectrum on the formation of microshoots and the root system. It was shown that the lighting regimes (R and FR ratio) had a stimulating effect on the roots and shoots growth regardless of the medium composition. Moreover, significant results were obtained under conditions of complete nutrition (mineral salts according to MS) in contrast to the control treatment (fluorescent lamps) and the treatment without salts. The best results were obtained at the R=FR treatment. This light treatment can be recommended for inclusion in the technology of clonal micropropagation of sweet potato. When red and blue spectra were added to normal illumination in different proportions, it did not lead to an increase in the morphogenetic potential of cultivated explants. The growth rate (μ) of the main shoot from axillary buds was about 2 times less than in the control treatment.