Evaluation of the Characteristics of Virus-free Sweetpotato and Its Use in Hybridization

Application of virus-free sweetpotato is a breakthrough of sweetpotato production. Several popular varieties were adopted to study their yield increase potential and their use in breeding in this research. The results showed that after virus-elimination, all varieties had a yield increase ranging from 14.95% - 91. 61% and marketable quality improvement, despite the changes in location and season. The changes of dry matter content and disease resistance were not significant. Virus-free sweetpotato performed vigorous vine growth and strong dry matter assimilation ability. Virus-free parents had a slightly high seed setting percentage, but its flowering ability and performance of off-springs were similar to that of its check plants.

Detection of Ratoon Stunting Disease in Virus-free Seedcane via Real-time Fluorescence Quantitative PCR

This study was to develop the real-time fluorescence quantitative PCR technique for detecting the ratoon stunting disease （RSD） in virus-free seedcane seedlings. Healthy tissue culture seedlings were obtained from six plants of sugarcane ROC22, which had been confirmed RSD-positive by detecting the sugarcane juice, by employing the sugarcane seedlings production protocol. Real-time fluorescence quantitative PCR was used to detect RSD pathogens in tissue culture sam- pies. The results showed that target fragment of RSD pathogens was not found in all 10 samples in real-time fluorescence quantitative PCR, with the Ct values of 37 - 39. The healthy tissue culture sugarcane seedlings do not carry RSD pathogens, indicating that adopting healthy seedcane seedlings production technique could thoroughly get rid of RSD pathogens.

A Preliminary Study on Tissue Culture and Rapid Propagation of Virus-free Plantlets of Benihoppe Strawberry

[ Objective] This study aimed to investigate the tissue culture and rapid propagation techniques of Benihoppe strawberry. [ Method] Shoot tips of new stolons of Benihoppe strawberry were used as experimental materials to analyze the effects of media type, cytokinin type and concentration, carbon source type and concentration, and light intensity on tissue culture and propagation of Benihoppe strawberry. [ Result] MS was the optimal media for plantlet propagation. In the media containing 1.2 ing/L BA （with addition of 0.1 mg/L NAA）, fresh weight, dry weight and propagation coefficient of strawberry plantlets reached the maxi- mum, which were 2.259 g, 0. 221 g and 12.4, respectively. The optimal carbon source was 30 g/L sucrose, and the optimal light intensity was 1 600 lx. [ Conclu- sion] The best media for tissue culture and rapid propagation of Benihoppe strawberry was MS ＋ BA 1.2 mg/L ＋ NAA 0. 1 mg/L ＋ sucrose 30 g/L ＋ agar 8 g/L. This study provided scientific basis for large-scale production of Benihoppe strawberry.

Expression of Invertase Genes in Virus-free Sugarcane

Virus-free sugarcane seedlings have improved biomass and sucrose content compared with ordinary seedlings, and sucrose invertases are key enzymes regulating sugarcane growth and sucrose accumulation. In this study, the differences in the expression levels of 3 invertase genes, CWI, SAI and NI, between virus- free and ordinary sugarcane seedlings were analyzed. Compared with ordinary sugarcane plants, the expression of CWI was mainly up-regulated in immature leaves and stems at elongation stage and leaves and immature internodes at maturation stage, and especially, greatly up-regulated in immature interuedes at maturation stage of virus-free plants. The expression of SAI and NI were mainly up-regnlated in leaves and immature internedes of virus-free plants at maturation stage, which might be beneficial to sugar accumulation and rapid utilization of monosaccharide in the stalks of virus-free plants. It is further indicated that virus-free treatment could significantly improve the expression of sucrose invertases at late growth period, and might facilitate the increase of plant biomass.

Study on Virus-free Breeding Technology of Potato Microtuber

It is the simplest,fastest and effective way to improve the yield level of potato by selecting high quality virus-free seed potato for field production and maintaining the original characters of virus-free minituber. Microtuber is featured by small volume,no pathogen,convenient storage and transportation,which can be induced in summer with high temperature and humidity,and overcome a series of problems such as poor survival rate of transplanted test-tube plantlets,and easy pollution of cutting tips. Therefore,it can replace conventional test-tube plantlets directly for reproduction. Meantime,if minitubers are sown ahead of time using cold frame,the growth stage of potato minituber will avoid the occurrence period of aphids. The use of gauze cover for insect prevention has good effect on maintaining the excellent characters of microtuber. The yield and quality of virus-free potato are greatly improved by means of virus-free culture of shoot tip seedlings,subculture propagation of virus-free seedlings,induction of microtubers by dark culture,cultivation of breeder’s seeds in greenhouse and screenhouse to preserve the characters of potato.

Correlations between delayed fluorescence of chlorophyll, metabolism and yield of plants. III. Influence of viral infection on field plants and new technology of clone selection of virus-free planting potato

At the end of potato plants vegetation virus in-fection induced both decrease in maximum amplitude of delayed fluorescence maximal amplitude and increase half time of its decrease, as well as reduction in the amount of stems, plants’ height and assimilation area surface, yield, acceleration of plants development and their early die-off. The differences of DF pa-rameters and yields between strongly and weakly infected plants increase in case of a combined virus infection. In industrial test of the selection of virus-free planting potato by the use of DF parameter, a rise in the yield and de-crease degree of viral infection of crops was obtained.

Analysis of genetic diversity and population structure in sweetpotato using SSR markers

Sweetpotato, Ipomoea batatas(L.) Lam., is an important food crop worldwide. Large scale evaluation of sweetpotato germplasm for genetic diversity is necessary to determine the genetic relationships between them and effectively use them in the genetic improvement. In this study, the genetic diversity of 617 sweetpotato accessions, including 376landraces and 162 bred varieties from China and 79 introduced varieties from 11 other countries, was assessed using 30 simple sequence repeat(SSR) primer pairs with high polymorphism. Based on the population structure analysis,these sweetpotato accessions were divided into three groups, Group 1, Group 2 and Group 3, which included 228, 136and 253 accessions, respectively. Consistent results were obtained by phylogenic analysis and principal coordinate analysis(PCoA). Of the three groups, Group 2 showed the highest level of genetic diversity and its accessions were mainly distributed in low-latitude regions. The accessions from South China exhibited the highest level of genetic diversity, which supports the hypothesis that Fujian and Guangdong were the first regions where sweetpotato was introduced to China. Analysis of molecular variance(AMOVA) indicated significant genetic differentiations between the different groups, but low levels of genetic differentiation existed between the different origins and accession types.These results provide valuable information for the better utilization of these accessions in sweetpotato breeding.

Construction of a high-density SSR genetic linkage map and identification of QTL for storage-root yield and dry-matter content in sweetpotato

Sweetpotato(Ipomoea batatas(L.)Lam.)is a widely grown food crop especially in developing countries.Increasing storage-root yield and dry-matter content has been the main breeding objective of the crop,and DNA marker-assisted breeding is needed for this purpose.In this study,using a mapping population of 500 F1 individuals from a cross between Xushu 18(female)and Xu 781(male),we constructed a highdensity genetic linkage map of sweetpotato using 601 simple-sequence repeat(SSR)primer pairs.The Xushu 18 map contained 90 linkage groups with 5547 SSR markers and spanned 18,263.5 cM,and the Xu 781 map contained 90 linkage groups with 4599 SSR markers and spanned 18,043.7 cM,representing the highest genome coverage yet reported for sweetpotato.We identified 33 QTL for storage-root yield and 16 QTL for dry-matter content,explaining respectively 6.5%–47.5%and 3.2%–18.9%of variation.These results provide a foundation for fine-mapping and cloning of QTL and for marker-assisted breeding in sweetpotato.

Evaluation of Four Varieties of Sweetpotato (Ipomeoa Batatas (L.) Lam) under Different Sources of Planting Material for Field Performance and Viral Load

Sweetpotato is an important crop for food security in many developing countries which is cultivated using vine cuttings. Studies have revealed that there are at least fifteen well characterized viruses known to infect sweetpotato of which 10 are economically important that contribute to yield reduction. Planting materials use by farmers are often infected by one or more of these viruses. The aim of this study was to evaluate three different sources of planting materials of different health status for their field performance and virus presence. The sources of planting materials were in vitro generated platelets, symptomless Field materials and Farmer’s materials. Four sweetpotato varieties Apomuden, Bohye, Ligri and Dadanyuie were selected from each source of planting material. The trial was laid in a split plot design with the sources of planting material allocated to main plots and the varieties to sub-plots. The plantlets of the four varieties were planted at Botanga Irrigation Scheme in Northern region of Ghana. Viral symptom scores were taken twice, score 1 being the average from 4 - 7 weeks after planting (WAP) and score 2 being the average from 8 - 11 WAP. Nitrocellulose Membranes Enzyme Linked Immunosorbent Assay (NCM-ELISA) kits were employed for the detection of sweetpotato viruses on the field. The source of planting materials significantly influenced (P In vitro generated material showed the least symptoms of virus followed by Field materials. Apomuden and Bohye varieties recorded the highest virus score in the first and second virus symptom observational score respectively. NCM-ELISA revealed that the viruses SPFMV, SPMMV, SPMSV, SPCFV, SPCSV, and CMV were significantly present among the different sources of planting materials. In vitro, Field and Farmer materials recorded NCM-ELISA score of 0.225, 1.075 and 1.500 respectively. Apomuden variety recorded the highest virus score in the assay. Vine and root yield was higher among the in vitro generated material. Farmers should use laboratory cleaned material however, in the absence of such material they should select field material showing no symptom of virus.

Steps To ward HIV Cure Two more HIV-infected patients appear to be virus-free after bone-marrow transplants

THIS year＇s International AIDS Society Conference on HIV Pathogenesis, Treatment and Preven-／tion, held in Kuala Lumpur, Malaysia, made major headlines when Timothy Hendch, an American doctor, announced that two more cancer patients may have been cured of HIV after receiving bone-marrow transplants to treat lymphoma. Both patients had been taking retroviral medication, and continued to do so after the transplants as their viral levels sank until doctors were unable to find any traces of HIV in the patients＇ blood.

优质高淀粉甘薯新品种齐宁26选育及特性鉴定

优质高淀粉甘薯新品种齐宁26是以济薯21为母本通过集团杂交选育而成.筛选试验及品质分析结果显示:该品种薯块平均干物率在平原地区和丘陵地区分别为32.28%和40.39%;薯块呈纺锤形,薯皮红色,薯肉淡黄色,结薯整齐集中,商品性好,食味优,抗根腐病、蔓割病及Ⅰ型薯瘟病,中抗Ⅱ型薯瘟病.齐宁26于2023年获得国家非主要农作物品种登记,证书编号为GPD甘薯(2023)370015,2024年获得植物新品种权,品种权号为CNA20221002661.

不同基因型甘薯品种胚性愈伤诱导和植株再生试验及福薯604胚性悬浮体系的建立

以福薯604、福菜薯18号、福薯7-6等16个甘薯品种为材料,通过茎尖诱导胚性愈伤,进行愈伤分化再生试验,比较不同基因型品种的愈伤诱导率、愈伤生长状态和植株再生率等的差异,结果表明,胚性细胞的诱导率和再生率因品种的不同而呈现明显差异.试验筛选出诱导率高、胚性愈伤状态好、分化再生率高的品种福薯604,并建立其胚性悬浮体系,测量胚性悬浮细胞的生长量,为甘薯优良品种福薯604遗传转化提供技术支持.

烯效唑处理对甘薯产量、土壤残留和后茬小麦生长的影响

在甘薯膨大初期设置叶面喷施和随水根部滴灌烯效唑的施用方式,研究烯效唑对甘薯块根产量、土壤残留和后茬小麦生长的影响.结果表明,适当的烯效唑处理能抑制甘薯地上部的生长,促进块根膨大,提高块根产量,其中叶面喷施的增产效果优于随水根部滴灌.高效液相色谱检测表明,各处理组土壤中烯效唑残留浓度均低于0.1 mg/kg,但是后茬土壤的生物效应试验显示,烯效唑有效成分施用量≥10 g/666.7 m^(2)时,土壤中的残留有可能对后茬作物产生影响.后茬小麦田间试验结果发现,随着甘薯生产中烯效唑施用期延后和剂量的增加,后茬小麦的株高和产量显著下降.因此,北方薯区春薯栽后67 d左右,进行<10 g/666.7 m^(2)烯效唑叶面喷施可以提高甘薯产量,同时对后茬小麦没有不良影响.

4种杀菌剂对甘薯茎腐病的防治效果研究

为筛选出防治甘薯茎腐病的有效药剂,研究了4种杀菌剂对甘薯茎腐病的防治效果,结果表明,薯苗生长前期用90%(质量分数,下同)氯溴异氰尿酸稀释液滴灌根部,防治效果可达94.64%;用70%甲基硫菌灵稀释液在栽插前浸苗20 min配合栽后每10 d滴灌1次,防治效果为68.53%;用可杀得3000(46%氢氧化铜)稀释液或6%春雷霉素水剂稀释液浸苗配合叶面喷施,防治效果均低于40%.因此,90%氯溴异氰尿酸稀释液可作为甘薯茎腐病防控的有效药剂.

15个淀粉甘薯主要农艺性状的综合评价

以15个淀粉甘薯品种为试材,采用灰色关联法、DTOPSIS法对淀粉甘薯在郑州栽培的8个农艺性状进行综合评价及分析,结果表明,15个淀粉甘薯品种的8个农艺性状均存在差异显著,变异系数在13.36%~92.01%,产量排名前三的品种为哈密、商薯19和徐薯37;相关分析表明,产量与商品率呈极显著正相关,单株分枝数与商品率呈显著正相关,7个农艺性状对淀粉甘薯产量影响大小依次为商品率>茎直径>单株分枝数>干物质>叶面积>最长蔓长>单株结薯数。DTOPSIS分析结果表明,综合排序前3名与产量前3名排序一致,仅有4个甘薯品种排序有所变化,其余均与鲜薯产量排序一致。综上分析,DOTPSIS法可作为淀粉甘薯品种综合评价的一种方法,筛选出哈密、商薯19和徐薯37可以作为新品种在郑州进行示范推广。

食用型甘薯新品种川薯233的选育

川薯233是以川薯224为母本,徐薯18为父本,通过杂交,经系统选育而成的食用型甘薯新品种.川薯233植株匍匐,结薯较集中,薯块纺锤形,薯皮浅红色,薯肉浅黄色,单株结薯5~6个.生产试验结果表明,平均鲜薯产量2509.37 kg/667 m^(2),平均薯干产量577.93 kg/667 m^(2).品质分析及抗病性检测结果显示,干物率为23.50%,抗根腐病,中抗茎线虫病和蔓割病,适宜在西南地区薯区种植.

甘薯储藏期低温胁迫的转录组分析和关键基因挖掘

甘薯在储藏过程中受到低温冷害会大大降低甘薯的商品价值,因此研究甘薯耐低温储藏的分子机制,减少低温在甘薯储藏过程中的影响具有重要意义。本研究选取了较耐低温储藏、不耐低温储藏以及表现居中的3个甘薯品种商薯19(S19)、烟薯25(Y25)和苏薯16(S16),分别在9℃和6℃储藏35 d。提取上述处理的薯块总RNA进行转录组测序和比较分析,发现与对照相比,S19在低温储藏后的差异表达基因较少,而Y25则相反,S16居中。差异表达基因KEGG和GO分析发现,甘薯块根在低温胁迫下蛋白酶体相关基因的表达水平较高。最终,通过比较不同品种不同温度下的转录组数据,得到响应储藏期低温胁迫的候选基因Ibat.Brg.02F_G010830,该基因注释为冷胁迫响应类受体蛋白激酶。qRT-PCR验证该基因的表达与转录组数据相一致。进一步分析了该基因及其等位基因和同源基因的进化关系,并分析了该基因在不同品种中的变异。本研究将为甘薯低温储藏响应机制解析以及耐低温储藏品种的选育提供支撑。

叶面喷施丹参碳点缓解甘薯低磷胁迫的转录组与代谢组学分析

为探究叶面喷施碳点(CDs)对低磷胁迫下甘薯幼苗生长发育的影响,发掘CDs调控甘薯根系响应低磷胁迫的关键基因,解析根系代谢产物与关键基因的协同变化,探讨CDs缓解甘薯低磷胁迫的机制,本研究以商薯19和徐薯32为研究对象,设置低磷水平下(0.01 mmol L-1KH2PO4)叶面喷施超纯水(CK1)、喷施丹参碳点(CDs)和正常磷水平下(1 mmol L-1KH2PO4)喷施超纯水(CK2) 3个处理,对不同处理甘薯根系进行转录组和代谢组学分析,同时考查不同处理中甘薯叶、茎和根系生物量和磷含量的变化。结果表明,叶面喷施丹参CDs显著增加了低磷胁迫下甘薯幼苗叶、茎和根系的生物量,提高了根系磷含量,增强了甘薯幼苗的耐低磷性。转录组分析结果显示,磷酸盐吸收和转运基因(PHO1、PHT1-4)、根系构型调控基因(ZAT6、ZFP5、PLT5)和肌醇磷酸盐生物合成基因(VIP2)在缓解甘薯低磷胁迫中发挥着关键作用。代谢组分析结果显示,CDs处理较CK1处理甘薯根系磷酸肌醇的表达量均显著降低。这表明,低磷胁迫下,叶面喷施CDs通过诱导甘薯根系高亲和磷吸收转运系统、优化根系构型等以提高甘薯对磷素的吸收能力,同时通过调整植株体内的磷代谢过程来维持磷稳态。但CDs介导下不同甘薯品种的低磷胁迫反应也存在差异。与CK1处理相比,CDs处理中还观察到商薯19根系磷酸乙醇胺和4-磷酸肌醇等磷酸酯的表达量显著降低;而徐薯32根系分泌的柠檬酸和草酸的表达量显著增加,它们能够活化土壤中的难溶性磷,促进植物磷吸收。这可能与不同甘薯品种本身的耐低磷性存在差异有关。研究结果可为建立甘薯磷养分高效的调控理论与调控新途径提供科学支撑和理论依据,也为后续针对纳米CDs缓解甘薯低磷胁迫的相关研究提供了候选分子资源。

甘薯抗性淀粉研究进展

甘薯是重要的淀粉作物,其块根中抗性淀粉(RS)含量较高,具备良好的产品开发潜力。要进一步促进甘薯RS的应用和推广,不仅需要筛选或培育出RS含量更高的甘薯品种,还需要加大开发甘薯深加工淀粉产品。除调控淀粉合成相关基因的表达外,生产实际中还可通过调整栽培措施等方式提高甘薯RS的含量。通过化学修饰法、物理法和酶解法等方法可制备甘薯RS产品,也能提高产品中RS的含量。本文系统综述了近年来甘薯淀粉的保健效果、RS含量的测定方法、影响甘薯淀粉中RS含量的因素、RS的制备方法及其特性等方面的进展,为未来甘薯中RS的制备、产量提高、产品开发和推广提供参考。

基施硫肥与遮荫对甘薯生长及同化产物积累的影响

为探究基施硫肥与遮荫对甘薯生长、光合及同化产物积累的影响,采用裂区设计,研究大田试验不同硫酸钾施用量(S含量为0、36、60、84 kg·hm^(-2))和不同遮荫处理(0、30%、60%遮光)对不同品种甘薯生长和地上部形态指标、光合效率及块根同化产物积累的影响。结果表明,基施硫肥促进了甘薯的地上部生长,增强了甘薯叶片的光合作用,提高了甘薯品质和产量,以36 kg·hm^(-2)硫肥用量下块根蔗糖含量较高,60 kg·hm^(-2)硫肥用量下块根有机酸和蛋白质含量较高。遮荫降低了甘薯的产量和地上部生物量,但30%遮荫有利于甘薯块根蔗糖和有机酸的积累,而60%遮荫下的甘薯块根蛋白质含量较高。综上,可施用36~60 kg·hm^(-2)硫肥以平衡产量与品质同步提升的矛盾,在小幅度牺牲产量的同时可通过不高于30%的遮荫提高甘薯块根蔗糖、有机酸与蛋白质的积累,以促进甘薯品质提升,提高甘薯生产的经济效益。本研究结果为甘薯优质栽培和营养元素富集提供了理论与技术指导。