Correlation of phytochemical content with antioxidant potential of various sweet potato (Ipomoea batatas) in West Java, Indonesia

Objective: To determine antioxidant activity and phytochemical content from various tubers extracts of sweet potato(Ipomoea batatas) and to explore the correlation of phytochemical content with their antioxidant activities. Methods: Antioxidant activities were tested using DPPH and FRAP assays. Total phenolic was calculated by Folin-Ciocalteu reagent, flavonoid content by Chang's method and correlation with their antioxidant activities were analyzed by Pearson's method. Results: PO2 showed highest antioxidant activity, which had the lowest IC50 DPPH(10.54 μg/m L) and the lowest EC50 FRAP(11.14 μg/m L). PO2 showed the highest total phenolic(11.91 g GAE/100 g) and total flavonoid content(17.83 g QE/100 g). There were significantly negative correlation between total phenolic content and flavonoid content in sample PO with their IC50 DPPH and EC50 FRAP. IC50 DPPH of sample PP and PO showed significantly positive correlation with their EC50 FRAP. Conclusions: Result of DPPH method shows that all different ethyl acetate and ethanolic tubers extracts of four varieties of sweet potato are classified as strong and very strong antioxidant. Result of DPPH and FRAP methods indicates that phenolic and flavonoid compounds in sample PO contributes together to antioxidant activities. Antioxidant activities of sample PP and PO by DPPH method are linear to FRAP method.

Comparison of Physicochemical,Organoleptic and Nutritional Abilities of Eight Sweet Potato(Ipomoea batatas)Varieties

In Martinique (F.W.I.), biodiversity of vegetable varieties remain unexploited due to public unawareness or supply problems. To further enhance the sweet potato, physicochemical, sensory and nutritional characteristics of eight varieties of sweet potato were established. The eight sweet potatoes cultivars were noticeably diverse with phenotypic, sensory, physicochemical and nutritional characteristics which were very varied. The eight cultivars grown in Martinique were advantageously positioned in relation to the globally identified sweet potato, regarding fibre, starch, potassium, copper, vitamin B1, B3 and B9 contents. Compared to the ordinary potato, Martiniquan sweet potatoes have a much better nutritional potential. Energy value and vitamin C levels were twice as much as in normal potatoes. Martiniquan sweet potatoes cultivars were also richer in minerals and vitamins, with 2.7 times more vitamin B9 and 63 times more beta-carotene than the ordinary potato.

Identification and Quantification of Allelochemicals from Selected Sweet Potato (<i>Ipomoea batatas</i>(L.) Lam.) Cultivars

Allelopathic compounds have the potential to inhibit the growth and development of other organisms in a diverse manner ranging from shifting nutrients and enhancing their growth to inflicting diseases. In addition, these compounds influence seedling growth and seed germination of various crops. The goal of this study was to identify and quantify different allelochemicals in various sweet potato cultivars through high-performance liquid chromatography techniques. Selected sweet potato slips (weight: 2.0 - 2.5 grams/slip) were propagated in separate glass tubes filled with 10.0 mL distilled water. Water extract from each glass tube was collected after 2, 4, and 6 weeks after transplanting (WAP) to identify and quantify allelochemical compounds by comparing their peaks with the retention time of standards. Results show that the concentration of allelochemicals in water extract was increased from 2 to 4 WAP but remained constant in the sixth week. Quantitative analysis revealed that the amount of chlorogenic acid was higher in all sweet potato cultivars compared to other allelochemicals. Some sweet potato cultivars, A5 and A39, exhibited higher allelopathy (18.28 - 19.37 ppm/slip) and reduced the height and biomass of Palmer amaranth the most due to the presence of increased concentration of combined allelochemicals, while other cultivars produced lesser allelochemicals (10.90 ppm/slip) and did not reduce the growth of the weed species. Allelopathic sweet potato cultivars high in chlorogenic acid production can effectively suppress Palmer amaranth with minimal dependence on chemicals to manage weeds and harmful pests under sustainable agricultural system.

甘薯(Ipomoea batatas L.)遗传转化几个因素的研究

目的：提高甘薯的遗传转化率,为建立快速高效的甘薯遗传转化体系奠定基础。方法：以甘薯多个优良栽培品种无菌苗茎切段为受体,利用农杆菌LBA4404/pSP10Z做介导,研究了影响甘薯转化的几个因素。结果：接种侵染时间对转化效率影响很大,以2-15min为宜,最高转化率可达32.14%;不同基因型的转化受体之间转化率差别较大;在培养过程中最后30min加入终浓度为50μmol/L AS的接种菌侵染的外植体,转化率较对照提高了2.02倍;共培养培养基中加入终浓度为50μmol/L的AS,转化率较对照组提高了6.11倍;AS终浓度为50μmol/L同时pH为4.8的共培养培养基有利于转化的发生,转化率较对照组提高了1.73倍;共培养培养基中脯氨酸的添加并不能提高转化率。结论：该研究为快速高效甘薯遗传转化体系的建立提供了依据。

甘薯(Ipomoea batatas (L.) Lam.)及其近缘野生种原生质体的植株再生

对甘薯品种高系14号及其近缘野生种I.triloba L、和I.lacunosa L,进行原生质体植株再生研究。从离体培养植株的叶柄分离出原生质体,将其培养在含有0.05mg/L 2,4-D和0.5mg/L激动素(KT)的MS培养基中,从原生质体获得了高频率的愈伤组织。培养8-12周后,将直径达2—3mm的小愈伤组织转移到添加0.05mg/L 2,4-D的MS培养基上。转移3-6周后,将愈伤组织进一步转移到添加吲哚乙酸(IAA)和6-苄基嘌呤(BAP)的MS培养基上,一些愈伤组织再生出植株。未再生植株的愈伤组织进一步在MS基本培养基上培养,它们也再生出植株。本研究从I.triloba原生质体获得高频率的植株再生;首次从I.lacunosa原生质体再生出植株;从高系14号原生质体也再生出完整植株。

甘薯(Ipomoea batatas(L.)lam)不定根根尖细微结构的初步研究

顶端分生组织细胞有高的核质比，胞质中可见前质体和其它细胞器．分化的组织原细胞中，皮层原细胞较中柱原和根冠表皮原细胞内前质体增多明显．组织原细胞内的前质体均匀散布高电子密度基质，并以溢痕方式分裂．淀粉颗粒最先出现在分化早期的皮层细胞和根冠表皮细胞中．较大液泡形成先见于根冠表皮细胞原和中柱内的分化早期细胞．外皮层细胞弦向壁纤维化增厚，径向壁薄，具凯氏带结构．提示甘薯不定根尖早期的外皮层细胞可以分化为既具支持保护作用也适应代谢转运功能的单位．

甘薯(Ipomoea batatas)原生质体的分离、培养与根的分化

用甘薯品种农林17号(中紫)的叶柄分离原生质体,对其在添加各种浓度的萘乙酸和激动素的改良细胞薄层培养基中进行悬浮培养。培养1～2 d 后,原生质体再生细胞壁,培养2～3 d 后,再生细胞发生第一次分裂,持续的细胞分裂形成小愈伤组织。悬浮培养的结果表明萘乙酸和激动素的适宜浓度分别为2.0～5.0mg/L 和1.0～5.0mg/L。此后,将小愈伤组织转移到MS 固体培养基上培养,小愈伤组织迅速生长。本试验达到根的分化.

甘薯(Ipomoea batatas(L.) Lam.)试管苗种质保存技术研究进展

甘薯种质资源的大田种植保存面临着严重的病毒感染以及病虫害、自然灾害的影响。由茎尖分生组织培养成无病毒苗并进行试管保存,是当前既经济又实用的方法。

Development of SRAP Markers Linked to a Gene for Stem Nematode Resistance in Sweetpotato, Ipomoea batatas (L.) Lam.

Sequence-related amplification polymorphism （SRAP） markers closely linked to stem nematode resistance gene were developed in sweetpotato, lpomoea batatas （L.） Lam. Using bulked segregant analysis （BSA）, 200 SRAP primer combinations were screened with the resistant and susceptible bulked DNA from the 196 progenies of an F1 single-cross population of resistant parent Xu 781xsusceptible parent Xushu 18, 77 of them showed polymorphic bands between resistant and susceptible DNA. Primer combinations detecting polymorphism between the two bulks were used to screen both parents and 10 individuals from each of the bulks. The results showed that primer combination A9B4 produced 3 specific bands in the resistant plants but not in the susceptible plants, suggesting that the markers, named Nspl, Nsp2 and Nsp3, respectively, linked to a gene for stem nematode resistance. Primer combination A3B6 also produced a SRAP marker named Nsp4 linking to the resistance gene. Amplified analysis of the 196 F1 individuals indicated that the genetic distance between these markers and the resistance gene was 4.7, 4.7, 6.3, and 9.6 cM, respectively.

Analysis of drought tolerance and genetic and epigenetic variations in a somatic hybrid between Ipomoea batatas (L.) Lam. and I. triloba L.

The somatic hybrid KT1 was previously obtained from protoplast fusion between sweetpotato （Ipomoea batatas （L.） Lam.） cv. Kokei No. 14 and its wild relative I. triloba L. However, its genetic and epigenetic variations have not been investigated. This study showed that KT1 exhibited significantly higher drought tolerance compared to the cultivated parent Kokei No. 14. The content of proline and activities of superoxide dismutase （SOD） and photosynthesis were significantly increased, while malonaldehyde （MDA） content was significantly decreased compared to Kokei No. 14 under drought stress. KT1 also showed higher expression level of well-known drought stress-responsive genes compared to Kokei No. 14 under drought stress. Amplified fragment length polymorphism （AFLP） and methylation-sensitive amplified polymorphism （MSAP） analyses indicated that KT1 had AFLP and MSAP band patterns consisting of both parent specific bands and changed bands. Fur- ther analysis demonstrated that in KT1. the proportions of Kokei No. 14 specific genome components and methylation sites were much greater than those of I. triloba. KT1 had the same chloroplast and mitochondrial genomes as Kokei No. 14. These results will aid in developing the useful genes ofI. triloba and understanding the evolution and phylogeny of the cultivated sweetpotato.

Cloning and Characterization of Eukaryotic Translation Initiation Factor 4E (eIF4E) Gene Family in Ipomoea batatas L. (Lam) for Understanding Hexaploid Sweetpotato-Virus Interactions

Characterization of genes related to sweetpotato viral disease resistance is critical for understanding plant-pathogen interactions, especially with feathery mottle virus infection. For example, genes encoding eukaryotic translation initiation factor (eIF)4E, its isoforms, eIF(iso)4E, and the cap-binding protein (CBP) in plants, have been implicated in viral infections aside from their importance in protein synthesis. Full-length cDNA encoding these putative eIF targets from susceptible/resistant and unknown hexaploid sweetpotato (Ipomoea batatas L. Lam) were amplified based on primers designed from the diploid wild-type relative Ipomoea trifida consensus sequences, and designated IbeIF4E, IbeIF(iso)4E and IbCBP. Comparative analyses following direct-sequencing of PCR-amplified cDNAs versus the cloned cDNA sequences identified multiple homeoalleles: one to four IbeIF4E, two to three IbeIF(iso)4E, and two IbCBP within all cultivars tested. Open reading frames were in the length of 696 bp IbeIF4E, 606 bp IbeIF(iso)4E, and 675 bp IbCBP. The encoded single polypeptide lengths were 232, 202, and 225 amino acids for IbeIF4E, IbeIF(iso)4E, and IbCBP, with a calculated protein molecular mass of 26 kDa, 22.8 kDa, and 25.8 kDa, while their theoretical isoelectric points were 5.1, 5.57, and 6.6, respectively. Although the homeoalleles had similar sequence lengths, single nucleotide polymorphisms and multi-allelic variations were detected within the coding sequences. The multi-sequence alignment performed revealed a 66.9% - 96.7% sequence similarity between the predicted amino acid sequences obtained from the homeoalleles and closely related species. Furthermore, phylogenetic analysis revealed ancestral relationships between the eIF4E homeoalleles and other species. The outcome herein on the eIF4E superfamily and its correlation in sequence variations suggest opportunities to decipher the role of eIF4E in hexaploid sweetpotato feathery mottle virus infection.

甘薯(Ipomoea batatas L.Lam.)基因启动子在根癌农杆菌中的作用

作者曾用自行构建的启动子探针型载体ｐＳＵＰＶ４，从甘薯（ＩｐｏｍｏｅａｂａｔａｔａｓＬ．Ｌａｍ．）总ＤＮＡ中克隆到了６５个在大肠杆菌中具有启动基因表达功能的ＤＮＡ片段．现研究发现，甘薯基因启动子片段在根癌农杆菌中也具有启动基因转录的功能，其启动功能的大小与启动子片段在大肠杆菌中启动卡那霉素抗性基因表达活性呈正相关，即原来卡那霉素抗性越高的，ＧＵＳ基因的酶活性越高．利用重组子ｐＩＢ２中插入片段所做的Ｓｏｕｔｈｅｒｎ杂交实验证实，该ＤＮＡ片段来源于甘薯基因组．

Development of a Process for Formulating Infant Flours from the Almonds of <i>Treculia obovoidea, Terminalia catappa</i>Linne as well as <i>Ipomoea batatas</i>Lam Leaves

In response to the malnutrition problem affecting children in Congo Brazzaville, we made three cooking-type infant flours from Treculia obovoidea, Terminalia catappa L. almonds and Ipomoea batatas L. leaves. The nutritional quality of the three infant flours we developed indicates 11.07% - 12.47% protein content, 9.92% - 14.87% fat content, 58.85% - 68.06% carbohydrate content, 1.50% - 2.18% ash and an energy intake varying between 399.84 and 439.37 Kcal. Functionally, our prepared flours have a water absorption capacity between 219.05 and 317.86 mL/g, an oil absorption capacity of 0.19 mL/g, a water solubility index varying from 29.66 - 41.03 and a swelling capacity of 250% - 320%.

甘薯和Ipomoea lacunosa的种间体细胞杂种植株再生及鉴定

用PEG融合法融合甘薯品种高系14号和近缘野生种Ipomoea lacunosa的原生质体,将融合原生质体培养在含有0.05mg/L 2,4 D和0.5mg/L KT的改良MS培养基中,4～5天后融合原生质体发生第一次细胞分裂。培养12周后,形成直径达1～2mm的小愈伤组织。将这些小愈伤组织转移到添加0.05 mg/L 2,4-D和0.5mg/L KT的MS培养基上,愈伤组织迅速增殖。将其中的70个愈伤组织培养在添加3.0mg/L BAP的MS培养基上,并进一步培养在MS基本培养基上,获得9株再生植株。过氧化物酶同工酶、酯酶同工酶和RAPD分析表明,其中2株再生植株(KL1和KL3)为种间体细胞杂种植株。

2种农作物对外来入侵植物空心莲子草茎节克隆繁殖与生长的影响

旨在评估农作物红薯与香茅草对入侵植物空心莲子草茎节克隆繁殖及生长的影响,以期为生态管理提供科学依据。实验采用红薯和香茅草的地上部分粉碎物,对空心莲子草茎节实施了3种不同处理:表层覆盖、混土栽培和水提液浇灌。通过测定茎节的存活率、生物量及酶活性等指标,评估不同处理对空心莲子草影响的效果。实验结果表明,在100 g/kg的处理浓度下,经过红薯混土栽培和香茅草水提液浇灌处理后,空心莲子草茎节的存活率分别降至55.56%和43.75%。相比之下,高浓度(100 g/kg)的水提液浇灌处理显著抑制了空心莲子草的茎长(红薯:3.37 cm,香茅草:2.25 cm)、根长(红薯:3.34 cm,香茅草:2.62 cm)、叶面积(红薯:0.46 cm^(2),香茅草:0.37 cm^(2))及生物量(红薯:0.19 g,香茅草:0.13 g)。此外,随着处理浓度的增加,超氧化物歧化酶(SOD)和过氧化氢酶(CAT)的活性以及丙二醛(MDA)含量上升,而过氧化物酶(POD)活性降低,这些变化反映了植物应对氧化应激的生理反应。综上所述,本研究发现100 g/kg的高浓度红薯与香茅草处理能显著抑制空心莲子草的茎节克隆繁殖与幼苗生长,尤其是通过水提液浇灌的方式效果更为显著。这一发现对于开发新的植物生长调控策略具有重要的实践意义。

不同温度和风速愈伤处理对甘薯贮藏品质的影响

甘薯(Ipomoea batatas(L.)Lam.)皮薄易损,在收获时极易受到机械损伤,从而造成腐烂,严重影响其经济价值。为了探讨不同温度和风速梯度对采后甘薯愈伤的作用效果,在天津以烟薯25号为材料开展了采后甘薯愈伤贮藏试验研究。结果表明,与CK组(12℃)相比,33℃的愈伤处理可以更好地降低甘薯块根贮藏期间的失重率、呼吸强度、丙二醛含量、纤维素酶活力和过氧化物酶活力,促进木质素合成以及可溶性固形物和淀粉的积累。交互效应分析表明,温度相较于风速对甘薯块根愈伤的影响更大,对损伤的恢复和品质的形成都有着显著效果。其中,以23℃配合1 m/s风速和33℃配合2 m/s风速的愈伤处理效果最好,能够有效促进愈伤组织的形成,延缓甘薯块根的水分散失,维持营养品质,延长贮藏时间,为甘薯采后贮藏保鲜技术的完善推广提供参考。

氮素不同控释期对甘薯光合特性及干物质积累与分配的影响

以甘薯[Ipomoea batatas(L.)Lam.]品种济薯25为试材,在大田条件下,设置控释期为30 d(T30)、50 d(T50)、70 d(T70)、90 d(T90)4个氮素控释肥处理,以施用等量养分含量的普通复合肥作为对照(CK),研究不同氮素控释期对甘薯光合特性及干物质积累与分配的影响。结果表明,氮素适当控释(控释期30~70 d)提高了甘薯中后期(80~160 d)叶片光合性能,促进了干物质向地下部的快速积累和转运分配,甘薯中后期叶片光合指标、地下部干物质积累(积累量和积累速率)和分配(分配比例和根冠比)指标均明显高于对照,其中以T50、T70较好,收获期(160 d)2个处理净光合速率、叶绿素SPAD、地下部干物质积累量、根冠比分别比对照提高了14.01%、11.32%、21.75%、18.48%和15.62%、11.84%、20.65%、18.84%;当控释期达90 d时,后期(120~160 d)地下部干物质积累与分配指标均低于对照,说明氮素控释期过长不利于甘薯后期干物质向地下部的快速积累和转运分配。

基于SSR标记分析31份甘薯品种(系)的遗传多样性

为了解不同甘薯资源材料之间的亲缘关系,以收集保存的31份甘薯品种(系)为研究对象,采用SSR标记分析不同材料之间的遗传多样性。结果表明,基于筛选获得的多态性较好的21对SSR标记,共检测到405个多态性等位位点,平均每对引物等位位点数为19.3个。31份甘薯材料遗传相似性系数在0.2829~0.9758之间,平均值为0.430419,说明遗传多样性丰富。聚类分析表明,在遗传距离为0.638时,可将31份甘薯品种(系)分为四个类群。

基于光谱反射率的甘薯叶片钾素营养监测与诊断

以商薯19和心香2个甘薯(Ipomoea batatas)品种为试验材料,通过设置不同梯度钾素处理测定叶片的光谱反射率,分别构建基于比值植被指数(RVI)的甘薯叶片钾含量和钾营养指数预测模型。结果表明,RVI与叶片钾含量构建的线性模型表明,RVI(R_(1598 nm),R_(1771 nm))对甘薯叶片钾含量的预测精度较高,回归方程为y=58.6010x-58.446(R^(2)=0.7414,RMSE=0.83),采用验证数据对线性模型进行检验,模型对不同钾肥水平处理下的甘薯叶片钾含量具有较好的预测能力(R^(2)=0.7324,RMSE=0.85);RVI与钾营养指数构建的线性模型表明,RVI(R_(700 nm),R_(1385 nm))对甘薯叶片钾营养指数的预测精度较高,回归方程为y=6.0329x-0.833(R^(2)=0.7688,RMSE=0.15),采用验证数据对线性模型进行检验,模型对不同钾肥水平处理下的甘薯叶片钾营养指数具有较好的预测能力(R^(2)=0.6395,RMSE=0.20);利用RVI能够较好监测与诊断甘薯钾素营养。

红薯栽培管理技术

实践中部分红薯栽培中存在施肥和管理水平不高等问题,直接影响红薯产量和品质。本文从红薯催芽与育苗、施肥与整地、选种与栽培、田间管理和收获等方面进行总结分析,为红薯绿色优质高产栽培提供参考。