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(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.

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。

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。

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%。

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。

滨海刺芹愈伤组织提取物中4种多酚含量测定及抗氧化、抗炎活性研究

采用热水回流法制备滨海刺芹愈伤组织提取物,基于高效液相色谱法建立同时测定滨海刺芹愈伤组织提取物中迷迭香酸、隐绿原酸、金丝桃苷、槲皮素-3-O-(6’’-O-乙酰基)-β-D-吡喃葡萄糖苷四种多酚含量的方法,测定提取物对DPPH自由基、ABTS自由基清除能力。同时通过CCK-8法检测筛选样品给药浓度,建立痤疮丙酸杆菌诱导HaCaT细胞炎症模型,评价其抗炎功效。结果表明,提取物中隐绿原酸含量最高,为5.23 mg/g;迷迭香酸、槲皮素-3-O-(6’’-O-乙酰基)-β-D-吡喃葡萄糖苷、金丝桃苷的含量依次为1.30,0.50,0.08 mg/g。提取物具有较好的抗氧化、抗炎能力,对DPPH自由基、ABTS自由基清除能力的IC_(50)值分别为0.3239,0.2965 mg/mL,对痤疮丙酸杆菌诱导的HaCaT细胞分泌IL-1β,IL-8也具有显著抑制作用(P<0.05)。

优质甘薯品种湛薯16的选育及栽培技术

湛薯16是湛江市农业科学研究院采用五圃制法,从徐紫薯3号自然杂交后代中选育出来的优质甘薯[Ipomoea batatas(L.)Lam.]品种。在2019—2020年南方薯区甘薯新品系多点鉴定试验中,湛薯16鲜薯平均产量33280.05 kg/hm^(2),薯干平均产量9748.95 kg/hm^(2),淀粉平均产量6364.35 kg/hm^(2),平均干物率29.14%。该品种鲜薯产量高、熟食口感佳,中抗蔓割病,适宜按照栽培技术推广。

基于叶绿体基因trnL-trnF、trnH-psbA和trnT-trnL序列的甘薯种质遗传多样性分析

【目的】利用叶绿体基因组(cpDNA)的间隔区序列(trnL-trnF、trnH-psbA和trnT-trnL)对甘薯种质进行遗传多样性分析,为其种质保护及开发利用提供理论依据。【方法】以从我国12个省份收集的52份甘薯种质为材料,从10个cpDNA间隔区序列的引物中筛选出能扩增单一、清晰明亮且稳定的序列引物,利用其PCR扩增筛选出间隔区序列,并进行测序及序列拼接。利用DnaSP 5.0进行序列特征分析,采用MEGA X计算52份甘薯种质材料的遗传距离,并构建系统发育进化树。【结果】筛选获得7对扩增结果较理想的引物,其PCR扩增产物经测序分析,共获得3个有效标记(trnL-trnF、trnH-psbA和trnT-trnL)。三者的拼接序列长度为2239 bp,共有7个变异位点,2个单一突变位点,5个简约信息位点,11个插入/缺失位点。在52份甘薯种质材料中,trnL-trnF、trnH-psbA和trnT-trnL序列的变异位点数量(Vs)分别为1、1和5个,单倍型数目(H)分别为2、4和5个,拼接序列的单倍型数目为10个;核苷酸多样性(π)和单倍型多样性(Hd)最高的序列分别为trnT-trnL(π=0.00052)和trnH-psbA(Hd=0.535)。trnL-trnF、trnH-psbA和trnT-trnL序列的Tajima’s D、Fu and Li’s D*和Fu and Li’s F*均无显著差异(P>0.05),符合中性进化模式。基于拼接序列构建的系统发育进化树显示,52份甘薯种质材料的遗传距离为0~1.1848,平均遗传距离0.1018,其分为五大类,其中第Ⅰ类~Ⅳ类仅含有少量种质,其余41份种质归为第Ⅴ类。【结论】52份甘薯种质材料的遗传变异较为丰富,但种质材料间的遗传多样性低,与cpDNA特性和甘薯遗传背景狭窄有关。基于trnL-trnF、trnH-psbA和trnT-trnL的拼接序列更能准确分析甘薯种质的遗传多样性,且有效划分不同类群,为甘薯集团育种提供候选材料。

Cloning and Characterization of a Salt Tolerance-Associated Gene Encoding Trehalose-6-Phosphate Synthase in Sweetpotato

Trehalose plays an important role in metabolic regulation and abiotic stress tolerance in a variety of organisms. In plants, its biosynthesis is catalyzed by two key enzymes： trehalose-6-phosphate synthase（TPS） and trehalose-6-phosphate phosphatase（TPP）. In the present study, a TPS gene, named IbTPS, was first isolated from sweetpotato（Ipomoea batatas（L.） Lam.） cv. Lushu 3 by rapid amplification of cDNA ends（RACE）. The open reading frame（ORF） contained 2 580 nucleotides encoding 859 amino acids with a molecular weight of 97.433 kDa and an isoelectric point（pI） of 5.7. The deduced amino acid sequence showed high identities with TPS of other plants. Real-time quantitative PCR analysis revealed that the expression level of IbTPS gene was significantly higher in stems of Lushu 3 than in its leaves and roots. Subcellular localization analysis in onion epidermal cells indicated that IbTPS gene was located in the nucleus. Transgenic tobacco（cv. Wisconsin 38） plants over-expressing IbTPS gene exhibited significantly higher salt tolerance compared with the control plant. Trehalose and proline content was found to be significantly more accumulated in transgenic tobacco plants than in the wild-type and several stress tolerance related genes were up-regulated. These results suggest that IbTPS gene may enhance salt tolerance of plants by increasing the amount of treahalose and proline and regulating the expression of stress tolerance related genes.

Molecular Cloning and Functional Characterization of a Salt Tolerance-Associated Gene IbNFU1 from Sweetpotato

Iron-sulfur cluster biosynthesis involving the nitrogen fixation（Nif） proteins has been proposed as a general mechanism acting in various organisms.NifU-like protein may play an important role in protecting plants against abiotic and biotic stresses.Based on the EST sequence selected from salt-stressed suppression subtractive hybridization（SSH） cDNA library constructed with a salt-tolerant mutant LM79,a NFU gene,termed IbNFU1,was cloned from sweetpotato（Ipomoea batatas（L.） Lam.） via rapid amplification of cDNA ends（RACE）.The cDNA sequence of 1 117 bp contained an 846 bp open reading frame encoding a 281 amino acids polypeptide with a molecular weight of 30.5 kDa and an isoelectric point（pI） of 5.12.IbNFU1 gene contained a conserved Cys-X-X-Cys motif in C-terminal of the iron-sulfur cluster domain.The deduced amino acid sequence had 66.08 to 71.99% sequence identity to NFU genes reported in Arabidopsis thaliana,Eucalyptus grandis and Vitis vinifera.Real-time quantitative PCR analysis revealed that the expression level of IbNFU1 gene was significantly higher in the roots of the mutant LM79 compared to the wild-type Lizixiang.Transgenic tobacco（cv.Wisconsin 38） plants expressing IbNFU1 gene exhibited significantly higher salt tolerance compared to the untransformed control plants.It is proposed that IbNFU1 gene has an important function for salt tolerance of plants.

AFLP Fingerprinting and Genetic Diversity of Main Sweetpotato Varieties in China

AFLP fingerprinting of the 98 main sweetpotato varieties planted in China has been constructed. Using 17 AFLP primer combinations which were selected from 1 208 primer combinations and generated the most amounts of polymorphic bands, AFLP analysis of the 98 main sweetpotato varieties gave a total of 410 clear polymorphic bands with an average of 24.12 polymorphic bands per primer combination. Each one of the 98 sweetpotato varieties could be clearly distinguished by EcoR I-cta/Mse I-ggc primer combination which generated the most polymorphic bands. AFLP-based genetic distance ranged from 0.0546 to 0.5709 with an average of 0.3799. The dendrogram based on AFLP markers indicated that sweetpotato varieties coming from the same regions or having same parents were clustered in the same groups. Analysis of molecular variance （AMOVA） revealed greater variations within regions （94.08%） than among regions （5.92%）. Thus, the genetic variations mainly existed within regions, while the variations among regions were very low in the tested sweetpotato varieties. Significant genetic variations existed between ＂Northern＂ and ＂Southern＂ sweetpotato varieties when Yangtze River was used as the dividing line.

Transcriptome profiling reveals insights into the molecular mechanism of drought tolerance in sweetpotato

Sweetpotato,Ipomoea batatas(L.) Lam.,is a globally important food crop and usually grown on arid-and semi-arid lands.Therefore,investigating the molecular mechanism of drought tolerance will provide important information for the improvement of drought tolerance in this crop.In this study,transcriptome analysis of the drought-tolerant sweetpotato line Xushu 55-2 was conducted on Illumina HiSeq 2500 platform.A total of 86.69 Gb clean data were generated and assembled into 2 671 693 contigs,222 073 transcripts,and 73 636 unigenes.In total,11 359 differentially expressed genes(DEGs) were identified after PEG6000 treatment,in which 7 666 were up-regulated and 3 693 were down-regulated.Of the 11 359 DEGs,10 192 DEGs were annotated in at least one database,and the remaining 1 167 DEGs were unknown.Abscisic acid(ABA),ethylene(ETH),and jasmonic acid(JA) signalling pathways play a major role in drought tolerance of sweetpotato.Drought-inducible transcription factors were identified,some of which have been reported to be associated with drought tolerance and others are unknown in plants.In addition,7 643 SSRs were detected.This study not only reveals insights into the molecular mechanism of drought tolerance in sweetpotato but also provides the candidate genes involved in drought tolerance of this crop.

甘薯抗病相关基因TAO1-like的TRAP分析

NBS-LRR是植物中已分离抗病基因最大的一类,TargetofAvrBOperation(TAO1)属于NBS-LRR类基因。以甘薯[Ipomoea batatas(L.)Lam.]抗病相关的TAO1基因作为靶标基因,设计出1条固定引物,与11条随机引物组合成11对引物。利用这11对引物对甘薯品种鄂薯11、鄂紫薯13进行TRAP-PCR扩增,发现11个引物组合扩增出清晰条带,且表现出良好的多态性。该研究获得与TAO1-like基因相关联的TRAP标记,该标记可进行甘薯群体的遗传多样性分析,为甘薯的抗病育种奠定基础。