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(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。

Cloning and Functional Analysis of Lycopene ε-Cyclase (IbLCYe) Gene from Sweetpotato, Ipomoea batatas (L.) Lam.

This paper reported firstly successful cloning of lycopene ε-cyclase （lbLCYe） gene from sweetpotato, lpomoea batatas （L.） Lam. Using rapid amplification of cDNA ends （RACE）, lbLCYe gene was cloned from sweetpotato cv. Nongdafu 14 with high carotenoid content. The 1 805 bp cDNA sequence oflbLCYe gene contained a 1236 bp open reading frame （ORF） encoding a 411 amino acids polypeptide with a molecular weight of 47 kDa and an isoelectric point （pI） of 6.95. IbLCYe protein contained one potential lycopene ε-cyclase domain and one potential FAD （flavinadenine dinucleotide）/NAD（P） （nicotinamide adenine dinucleotide phosphate）-binding domain, indicating that this protein shares the typical characteristics of LCYe proteins. The gDNA oflbLCYe gene was 4 029 bp and deduced to contain 5 introns and 6 exons. Real-time quantitative PCR analysis revealed that the expression level of IbLCYe gene was significantly higher in the storage roots of Nongdafu 14 than those in the leaves and stems. Transgenic tobacco （cv. Wisconsin 38） expressing [bLCYe gene accumulated significantly more ^-carotene compared to the untransformed control plants. These results showed that lbLCYe gene has an important function for the accumulation of carotenoids of sweetpotato.

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.

Identification of QTLs for Starch Content in Sweetpotato(Ipomoea batatas(L.) Lam.)

Sweetpotato （Ipomoea batatas （L.） Lam.） breeding is challenging due to its genetic complexity. In the present study, interval mapping （IM） and multiple quantitative trait locus （QTL） model （MQM） analysis were used to identify QTLs for starch content with a mapping population consisting of 202 F1 individuals of a cross between Xushu 18, a cultivar susceptible to stem nematodes, with high yield and moderate starch, and Xu 781, which is resistant to stem nematodes, has low yield and high starch content. Six QTLs for starch content were mapped on six linkage groups of the Xu 781 map, explaining 9.1-38.8% of the variation. Especially, one of them, DMFN 4, accounted for 38.8% of starch content variation, which is the QTL that explains the highest phenotypic variation detected to date in sweetpotato. All of the six QTLs had a positive effect on the variation of the starch content, which indicated the inheritance derived from the parent Xu 781. Two QTLs for starch content were detected on two linkage groups of the Xushu 18 map, explaining 14.3 and 16.1% of the variation, respectively. They had a negative effect on the variation, indicating the inheritance derived from Xu 781. Seven of eight QTLs were co-localized with a single marker. This is the first report on the development of QTLs co-localized with a single marker in sweetpotato. These QTLs and their co-localized markers may be used in marker-assisted breeding for the starch content of sweetpotato.

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.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．

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。

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%.

Alyssum maritimum(L.) Lam.的组织培养研究

将Alyssum maritimum(L.)Lam.的种子灭菌后,分别接入培养基MS+6-BA 1.0 mg/L+NAA0.2 mg/L、MS+6-BA 1.5 mg/L+NAA 0.2 mg/L、MS+6-BA 2.0 mg/L+NAA 0.2 mg/L、MS+6-BA2.5 mg/L+NAA 0.2 mg/L中,得到无菌苗.取20 d的无菌苗叶子切成3 mm×2 mm的小块,接入同样的培养基中诱导芽,在MS+6-BA 2.5 mg/L+NAA 0.2 mg/L培养基上分化得到芽,将芽转入不同NAA浓度MS培养基上生根.实验表明,A.maritimum(L.)Lam.芽诱导最适合的培养基是MS+6-BA 2.5 mg/L+NAA 0.2 mg/L.

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.

甘薯淀粉含量的QTL定位

本研究以高淀粉甘薯品种漯徐薯8号(母本)和低淀粉甘薯品种郑薯20(父本)杂交得到的F1分离群体,选择其中240个单株为材料,以该群体所构建的分子连锁图谱为基础,以2008年和2009年所测定的淀粉含量为指标,采用复合区间作图法并利用QTLMapper2.0软件分析了甘薯淀粉含量的QTL。实验结果表明,检测到了1个主效位点,位于父本郑薯20的Z31连锁群上a02b40.02ds**和a08b37.03fs*两个标记之间,QTL的加性效应为-0.73,解释表型变异的7.70%。定位甘薯淀粉含量相关的QTL,将为发掘与淀粉含量相关的基因奠定基础。

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。

HPLC法测定药用甘薯西蒙Ⅰ号中咖啡酸的含量

目的 建立测定西蒙 号叶中有效成分含量的方法 ,比较不同年份的西蒙 号叶中咖啡酸的含量差异。方法 采用 HPL C对西蒙 号叶中咖啡酸的含量进行测定。结果 咖啡酸在 10 .33～ 16 5 .2 8μg/ m L 具有良好的线性关系 ,平均回收率为 99.38% ,RSD=1.36 % (n=6 )。结论 该方法灵敏、准确、专属性强 ,适用于西蒙 号药材中咖啡酸的测定。

甘薯叶绿体rbcL基因的克隆与序列分析

根据烟草、水稻和菠菜叶绿体的全基因组序列设计引物,以甘薯的叶绿体基因组DNA为模板,PCR扩增包含甘薯叶绿体rbcL完整基因(GenBank登录号为AY942199)在内的一段序列。序列分析表明:此片段的全长为1627bp,包括1443bp的编码区序列在内,推测编码480个氨基酸,同时构建了此片段的限制性酶切图谱。相似性比较显示,此基因编码区序列与烟草、菠菜、小麦、水稻、玉米、矮牵牛、紫花苜蓿、拟南芥、莨菪、葡萄以及甜菜的rbcL基因核苷酸的同源性为85%～98%,氨基酸的同源性为92%～95%。

不同熟化方式下甘薯果胶含量与质构相关性分析

目的比较分析不同品种的甘薯在不同熟化方式下果胶含量的差异以及与质构指标的相关性。方法采用咔唑比色法对甘薯中的可溶性果胶含量和原果胶含量进行测定,并测定了生、熟薯块的质构指标。结果不同甘薯品种的生、烤和蒸薯中均含有可溶性果胶和原果胶,且各品种的果胶含量存在差异。在生薯的果胶含量中,原果胶含量最高;在烤薯和蒸薯的果胶含量中,可溶性果胶含量最高。参试品种的生薯、烤薯和蒸薯的质构指标间差异性较大。在生薯中,冀元2号的硬度最高,冀元1号的黏附性最大,冀元2号的胶黏性最大;烤薯中冀薯9号的硬度最大,慧谷2号的弹性最大,普薯32号的内聚性最高;蒸薯中慧谷2号的硬度最大,哈密的弹性最大,冀元1号的胶黏性最大。相关性分析结果表明,质构指标与可溶性果胶含量、原果胶含量之间存在着较好的相关性:生薯的原果胶含量与干物率呈极显著正相关,与黏附性呈极显著负相关;烤薯可溶性果胶含量与原果胶含量之间呈显著负相关;蒸薯的可溶性果胶含量与弹性呈显著正相关,原果胶含量与回复性呈显著负相关。结论该研究结果可为甘薯品种适宜加工方式的选择和评价,以及后续甘薯新品种的选育提供参考。

4QL―1型甘薯起垄收获多功能机的设计与试验

设计了一款可实现甘薯施肥、起垄、镇压和收获作业的起垄收获多功能机,并阐述了整机和关键部件结构设计、工作原理及技术参数。在粘重土壤区试验考核表明,该机性能稳定,作业顺畅,起垄主要指标为:土垄垄形一致性为97%,土壤容重变化率为27%,邻接垄垄距合格率为90%;收获主要指标为:明薯率为97%,漏挖率为0.3%,伤薯率为1%,破皮率为1.5%。

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。

甘薯黄酮对CCl_4所致肝细胞损伤的保护作用

目的研究甘薯黄酮对CCl4所致肝细胞损伤的保护作用及其初步作用机制。方法体外培养人正常肝细胞株HL7702,MTT法测定甘薯黄酮对HL7702细胞活性的影响;建立CCl4损伤肝细胞模型,测定甘薯黄酮对CCl4损伤肝细胞增殖活性、谷丙转氨酶(ALT)、谷草转氨酶(AST)、丙二醛(MDA)和超氧化物歧化酶(SOD)含量的变化;琼脂糖凝胶电泳法检测甘薯黄酮对CCl4损伤肝细胞凋亡的影响。结果甘薯黄酮在一定剂量范围(1～1 000μg/ml)内对肝细胞无毒性,超过一定剂量(3 000μg/ml)时,具有细胞毒性;甘薯黄酮可以抑制CCl4所致肝细胞活性降低,能明显抑制CCl4损伤后ALT、AST、MDA水平的升高和SOD活性的减弱;400μg/ml甘薯黄酮能减轻CCl4所致的肝细胞凋亡。结论甘薯黄酮对体外培养正常人肝细胞株的安全剂量范围是1～1 000μg/ml。甘薯黄酮在安全剂量范围内能保护CCl4诱导的HL7702细胞损伤,减轻CCl4所致细胞凋亡。