Variation Laws of Anthocyanin Content in Roots and Their Relationships with Major Economic Traits in Purple-Fleshed Sweetpotato Ipomoea batatas (L.) Lam

Variation laws of anthocyanin content in root during the development and among the varieties, and their relationships with major economic traits in purple-fleshed sweetpotato [Ipomoea batatas （L.） Lam] were studied in the present article. The dynamics of 20 economic traits in 13 purple-fleshed sweetpotato varieties at 20, 40, 60, 80, 100, 120, and 140 d after their transplanting were investigated, and these traits included anthocyanin content in root, length of the longest vine, number of base branches, root number, dry matter contents in stem, foliage and root, fresh/dry weight of root, fresh/dry weight of stem, flesh/dry weight of foliage, flesh/dry weight of stem and foliage, flesh/dry weight of whole plant, and rations of photosynthate to root, stem, and foliage. The correlations between the variations of anthocyanin content and the other 19 economic traits among varieties and during the whole developing stages, and the correlations of daily increase of anthocyanin content with other l0 kinds of yields were analyzed. The results showed that： （1） During the whole development, the anthocyanin content had three variation types, i.e. a slow-increase type, a fluctuating-change type, and a deviousrising type, and had different responses to the growth of length of the longest vine, number of base branches, flesh/dry yield of root, and photosynthate allotments. （2） The anthocyanin contents among 13 varieties began to have significant difference after 20 d, and showed completed differentiation during 40-100 d, which had significantly negative correlationships with the number of base branches, fresh/dry yield of root, photosynthate allotment ratio to root, and had significant positive correlationships with dry matter content of root, length of the longest vine, fresh/dry yield of stem, dry yield of whole plant and photosynthate allotment ratio to foliage. （3） Because of the significantly negative correlation between daily increase of anthocyanin content and dry matter weight of root, the anthocyanin accumulation competed with dry matter accumulation for photosynthate in root, and the competitive relation was resolved in different ways in different purple-fleshed sweetpotato （PFSP） varieties. So, there had three variation types of anthocyanin content among PFSP varieties during their development, and had different correlations between these variations of anthocyanin content and the major economic traits.

Breeding and Cultivation Techniques of a New Table Use Purple-fleshed Sweetpotato Cultivar,Xuzishu 2

Xuzishu 2 is a new high-quality table use purple-fleshed sweetpotato cultivar bred from hybrid progenies of AIS35-2 x Xushu 22-5 by Jiangsu Xuzhou Sweetpotato Research Center. In the sweetpotato variety regional trial of Jiangsu Province during 2007 - 2008, average fresh storage root yield was 30 185.3 kg/hm2 ; average dry matter content was 29.26% ; average dry storage root yield was 8 868.7 kg/hm2. In the sweetpotato variety production test of Jiangsu Province, average fresh storage root yield was 30 683.9 kg/hm2 ; average dry storage root yield was 9 399.0 kg/hm2. Multi-location sampling analysis in the regional trial indicated that the anthocyanin content in fresh storage roots was 104.6 μg. Xuzishu 2 was approved by Crop Variety Approval Committee of Jiangsu Province in March 2010, which exhibited high fresh storage root yield, sweet taste, high anthocyanin contem, good commodity, root rot resistance, and was tolerant to moisture and easy to store. Therefore, Xuzishu 2 is a high-quality purple-fleshed sweetpotato variety suitable for consumption and food processing, which should be cultivated in medium- and high-fertility fields with management procedures of suitable high density, early planting and early harvest.

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.

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.

甘薯U6启动子克隆及其转录活性分析

在CRISPR/Cas9基因编辑系统中,U6启动子可以通过驱动sgRNA的表达来编辑目的基因,因而其转录活性会影响基因编辑效率。尽管人们已经在拟南芥、玉米、大豆、棉花等植物中开展了U6启动子的克隆与应用研究,然而目前在甘薯中U6启动子的相关研究还未见报道。本研究利用拟南芥的AtU6 SnRNA的保守序列在三浅裂野牵牛(Ipomoea trifida)基因组数据库中搜索候选U6 RNA,然后在其上游搜索到2个不同的候选U6启动子,长度分别为526 bp(IbU6p-1)和532 bp(IbU6p-2);序列比对分析结果显示,甘薯的U6启动子具有上游序列元件(USE)以及TATA-box,其序列也与拟南芥高度相似。然后,利用获得的U6启动子核酸序列构建了能够驱动萤火虫荧光素酶基因(LUC)表达的重组框U6::LUC。最后,将含有上述重组载体的根癌农杆菌瞬时转化到本氏烟草叶片和甘薯愈伤组织中,并通过荧光成像技术分析荧光素酶活性。结果发现,在烟草及甘薯愈伤组织中2个甘薯U6启动子均能驱动LUC基因表达,具有转录活性。同时,IbU6p-2的转录活性无论是在烟草叶片中还是在甘薯愈伤组织中都显著高于拟南芥U6启动子。本研究结果为进一步发展甘薯基因编辑技术提供了参考。

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。

甘薯疮痂病菌的生物学特性和产孢方法研究

探究甘薯疮痂病菌(Elsinoe batatas)的生物学特性,筛选疮痂病菌在人工培养基上快速、大量地产生分生孢子的方法,为甘薯抗疮痂病育种提供依据。以疮痂病病原菌菌株CRI-CJ2为研究对象,采用菌丝生长速率法测定在不同培养基、pH和光照处理条件下的菌落生长直径,利用凹玻片悬滴法测定在不同温度、pH和光照处理条件下的分生孢子萌发率,比较Fries液体培养法、摇菌法和菌丝涂布法等3种方法的诱导产孢效果。结果表明,最适菌丝生长的培养基为PDA,pH 6~7,致死温度为48℃、10 min,光照对菌丝生长无显著影响,但连续光照使菌落呈鲜红色;分生孢子萌发最适pH 5,最适温度为25℃,致死温度为48℃、10 min,光照对分生孢子萌发影响不显著;采用菌丝涂布法可使疮痂病菌在培养第12天分生孢子产孢量达7.09×10^(7)个/mL,分生孢子萌发率为24%,产孢量和孢子活力均高于摇菌法,采用Fries液体培养法未观察到分生孢子及产孢结构。可见,选用适宜的培养基、pH能促进菌丝体生长,菌丝涂布法具有产孢快、产孢量大的优点,是一种适合甘薯疮痂病菌分生孢子诱生的方法。

施氮量和种植密度对甘薯封垄期干物质积累和分配及收获期产量的影响

为探讨氮肥用量和种植密度对甘薯封垄期干物质积累和分配及收获期产量的影响,提升海南地区甘薯栽培技术,于2019—2020年进行田间试验,以鲜食型甘薯品种高系14为试验材料,设置3个种植密度,即47600株/hm^(2)(D_(1))、71400株/hm^(2)(D_(2))、142900株/hm^(2)(D_(3));4个施氮量,即0 kg/hm^(2)(N_(0))、60 kg/hm^(2)(N_(1))、120 kg/hm^(2)(N_(2))、180 kg/hm^(2)(N_(3)),采用双因素裂区设计,以种植密度为主区,施氮量为副区,研究不同种植密度和施氮量组合对高系14封垄期的光合特性、叶绿素相对含量(SPAD)、茎叶生长、源库干物质积累与分配特性、封垄期结薯特性、收获期产量及其构成因素和商品性的影响。结果表明:在同一种植密度下,甘薯封垄期的叶片净光合速率(P_(n))、茎叶鲜重、分枝数、最长蔓长、单株结薯数及商品薯单薯重随施氮量的增加先增加后降低,在N_(1)处理时最大;甘薯产量随施氮量的增加先增加后降低,在N_(2)处理时最大,较N0提高了32.0%,但N_(2)与N_(1)处理间无显著差异;在同一施氮量下,甘薯块根干物质分配比随种植密度的增加先增加后降低,D_(2)处理达到最大但D_(2)与D_(3)处理间无显著差异;根冠比和产量随种植密度的增加显著增加,在D_(3)处理时最大,其中D_(3)产量较D_(1)、D_(2)分别提高了30.9%和24.1%。相关性分析结果表明,在对块根干物质积累和分配的影响效应中,施氮量和种植密度均有显著影响,而对甘薯收获期产量的影响效应中,种植密度与收获期产量呈极显著正相关,相关系数为0.704。综合本试验结果,当施氮量为60 kg/hm^(2)、种植密度为142900株/hm^(2)处理(D_(3)N_(1))时,高系14的产量最高,达到30.1 t/hm^(2),其对应薯块商品率为94.3%,均为所有处理中最佳。

甘薯突变体库构建的研究进展

甘薯具有重要的淀粉价值、鲜食价值、菜用价值、观赏价值和药用价值,市场前景广阔.创制甘薯突变体库是进行甘薯种质资源创新及品种改良的有效途径.综述了目前甘薯突变体库构建的主要方法,即理化诱变,以及CRISPR(clustered regularly interspaced short palindromic repeats)基因编辑的新方法,并结合甘薯突变体库资源现状,对今后的研究进行了展望,以期为甘薯种质资源创制和基因功能研究提供参考.

基于InDel标记分析305份中国甘薯登记品种遗传多样性

对甘薯育成品种进行亲缘关系评价,是了解其遗传背景并有效利用种质资源的重要前提。利用本课题组前期开发的23对InDel引物对305份中国甘薯登记品种进行基因型分析,共扩增出56个条带,其中53个条带具有多态性,多态率达94.6%。多态信息量(PIC)、Nei′s遗传多样性指数(H)、观测杂合度(Ho)和期望杂合度(He)的平均值分别为0.4098、0.4451、0.6003、0.4460。群体结构分析表明,群体数在K=2时ΔK达到最大值,K=4时有个小高峰;北方薯区和长江流域薯区在2个组群内均匀分布,南方薯区大部分(72.97%)汇聚在组群2。主坐标分析(PCoA)中南方薯区有部分汇聚,整体没有划分出明显的簇群。聚类结果将群体划分为4个主要类群,北方薯区和长江流域薯区的品种在类群Ⅰ、Ⅱ、Ⅲ和Ⅳ中均匀分布,南方薯区主要(77.03%)集中于类群IV,这一聚类结果与群体结构研究、主坐标分析基本一致。通过系谱分析筛选出登记品种的13个主要亲本材料,各育种单位存在重复利用亲本进行正反交培育的情况。本研究将分子标记结果与系谱信息相结合,初步表明中国甘薯登记品种的亲缘关系较近,遗传背景狭窄,为甘薯的种质创新、新品种选育提供参考。