藕莲(地下膨大茎)贮藏及其生理生化研究进展

综述了影响莲藕 (地下膨大茎 )贮藏的主要因素、莲藕的贮藏方法、莲藕采收后生理生化特性的研究 ,以及莲藕的褐变机理。     

不同预冷方式对采后莲藕贮藏品质的影响

以青浦莲藕为主要对象,研究冷水预冷和冷库预冷两种方式对于莲藕贮藏保鲜的影响,考察其在保鲜柜（4±0.5）℃、15天的贮藏期间的失重率、色泽、硬度、可溶性固形物、相对电导率等的变化。结果表明：与未经预冷的莲藕样品相比,冷水和冷库预冷能够显著降低莲藕失重率、延缓莲藕表皮色泽变化、维持莲藕的可溶性固形物含量,然而冷库预冷对莲藕在贮藏后期的细胞膜造成损伤,从而降低莲藕品质,而冷水预冷能够保持莲藕硬度,由此表明冷水预冷对莲藕具有更好的保鲜效果。     

东洞庭湖莲藕种植区土壤重金属污染及其对莲藕重金属含量的影响

通过对东洞庭湖莲藕种植区的野外调查, 揭示了土壤重金属污染的潜在生态风险及其对莲藕重金属含量的影响。土壤重金属镉(Cd)、铅(Pb)、铜(Cu)、锌(Zn)含量均高于洞庭湖背景值, 以Cd 污染最为严重, 潜在生态风险指数高, 属极重度生态风险级。莲藕干物质中重金属含量较高, 其中Cd、Pb 含量分别达到3.43 mg·kg^-1 和6.84 mg·kg^-1。不同种植区域之间, 莲藕重金属含量差异显著, 以君山区挂口镇的莲藕重金属含量最高。莲藕重金属含量的高低与土壤重金属含量呈显著正相关关系(P<0.01)。可见, 东洞庭湖莲藕种植区土壤重金属污染是导致莲藕重金属含量过高的直接原因, 建议在污染较重的区域, 减少莲藕种植, 开展土壤重金属污染治理, 引导莲藕产业健康发展。     

莲藕多酚氧化酶同工酶的比较分析

采用垂直板聚丙烯酰胺凝胶电泳技术,对同一植株莲藕的不同部位、不同湖区野生莲藕以及不同品种的特定部位的多酚氧化酶(PPO)同工酶进行了分析。结果表明,同一植株莲藕不同部位PPO同工酶带有一定的特异性, 其主要表现在区带数目、迁移位置和区带染色深浅三方面;而不同湖区野生莲藕以及不同品种莲藕,处于同一生长周期、同一部位中的PPO同工酶遗传多样性则较低。     

莲藕对金属污染物的吸收与富集

莲藕(Nelumbo nucifera Gaertn)有“出污泥而不染”的美誉。莲藕给人们突出的印象:生命力强,长势旺盛,能抵抗一般自然灾害,对土壤无过高要求,pH值在5.6—7.4之间,莲藕长势无差异。在低或高浓度SO2的污染环境中,莲藕生长发育均无影响1。       

莲藕的化学成分与生物活性研究进展

对莲藕(Nelumbo nucifera Gaertn)不同组织(莲藕、荷花、荷叶、莲梗、莲子、莲心、莲蓬)的有效化学成分(类黄酮、酚类、生物碱、三萜、多糖、SOD、膳食纤维、挥发油)作了简要的综述,并对其主要的生物活性进行了归纳,以期对莲藕资源的综合利用提供理论依据。     

莲藕Na~+/H~+逆向转运蛋白基因-LrNHX的克隆及表达分析

[目的]寻求解决莲藕栽培种普遍对盐敏感的途径,从耐盐野生种中克隆了一个候选耐盐基因-LrNHX的全长c DNA序列,并对其表达进行分析,为今后利用基因工程技术改良莲藕耐盐性奠定基础。[方法]根据NCBI数据库中的莲藕Na~+/H~+逆向转运蛋白基因序列设计引物,利用PCR技术在莲藕叶片中克隆LrNHX,再利用半定量RT-PCR研究了250 mmol/L Na Cl处理0 h、6h、12 h、18 h、24 h和30 h时莲藕叶片中LrNHX的表达情况。[结果]LrNHX cDNA全长1 861 bp,编码526个氨基酸。Blast比对后发现该基因和与胡杨(ACX46912.1)、毛白杨(AAX37333.1、番茄(CAC83608.1)、拟南芥(NP 178079.2)的同源性分别达88%、87%、83%、82%。半定量RT-PCR结果表明,该基因在250 mmol/L Na Cl处理12 h后表达显著增高,说明LrNHX受盐诱导。[结论]LrNHX参与了莲藕耐盐信号的转导。     

莲藕盐诱导基因CBL2的克隆与表达

[目的]CBL家族基因在植物耐盐过程中起到重要的作用。该实验从耐盐莲藕中克隆了CBL2基因的全长cDNA序列,对其表达进行分析。[方法]根据前期测序得到的转录组数据,发掘到莲藕CBL2的ESTs序列,并克隆到全长莲藕CBL2。在此基础上,对CBL2的表达进行分析。[结果]CBL2的cDNA序列长度645 bp,与其他物种CBL2的同源性分析对比结果表明,莲藕CBL2与山葡萄Va CBL2的相似率较高,同源性达90%以上。利用半定量和qRT-PCR对克隆到的莲藕基因CBL2的表达进行分析,结果表明CBL2受NaCl诱导,CBL2在NaCl处理后12 h表达量达到最大值。另外CBL2在ABA处理后表达量增加,处理6 h后达到最大值。[结论]CBL2在NaCl处理12 h与ABA处理6 h诱导表达,暗示CBL2基因在莲藕耐盐特性方面起重要的作用,并参与ABA信号转导途径。     

新兴垸低湖田莲藕引种栽培研究

本文报道了作者在湖北省监利县新兴垸低湖田进行的莲藕优良品种引种栽培试验结果,从低湖田试验莲藕的生长发育、产量、经济效益及生态适应性等方面说明了低湖田植藕是该区涝渍地开发利用的有效途径,同时简要提及了低湖田植藕应注意的若干技术问题。     

莲藕研究进展

综述了莲藕在分类、生长发育、遗传育种、组织培养、生理学特性等方面的研究进展.     

Whole genome re‐sequencing reveals evolutionary patterns of sacred lotus (Nelumbo nucifera)

Sacred lotus (Nelumbo nucifera or lotus) is an important aquatic plant in horticulture and ecosystems. As a foundation for exploring genomic variation and evolution among different germplasms, we re‐sequenced 19 individuals from three cultivated temperate lotus subgroups (rhizome, seed and flower lotus), one wild temperate lotus subgroup (wild lotus), one tropical lotus group (Thai lotus) and an outgroup (Nelumbo lutea). Through genetic diversity and polymorphism analysis by non‐missing SNP sites widely distributed in the whole genome, we confirmed that wild and Thai lotus exhibited greater differentiation with a higher genomic diversity compared to cultivated lotus. Rhizome lotus had the lowest genomic diversity and a closer relationship to wild lotus, whereas the genomes of seed and flower lotus were admixed. Genes in energy metabolism process and plant immunity evolved rapidly in lotus, reflecting local adaptation. We established that candidate genes in genomic regions with significant differentiation associated with temperate and tropical lotus divergence always exhibited highly divergent expression pattern. Together, this study comprehensive and credible interpretates important patterns of genetic diversity and relationships, gene evolution, and genomic signature from ecotypic differentiation of sacred lotus.     

莲的非可食用部分中生物碱分布

研究了莲的非可食用部分荷叶、莲子心、莲房、藕节、莲子壳和藕皮中生物碱的组分及含量。采用乙醇水溶液从非可食用部分提取生物碱,然后用高效液相色谱法进行测定。结果表明莲子心提取物中含有5种主要的生物碱,其中4种为莲心碱、异莲心碱、荷叶碱和甲基莲心碱。除莲子心外的其他部分的提取物组分较相似,都含有6～8种主要的生物碱。荷叶碱在荷叶中的含量最高,可达149.64μg/g;莲心碱、异莲心碱和甲基莲心碱在莲子心中的含量最高,分别为457.76、6155.85、1420.90μg/g。莲的六个非可食用部分中都含有5～8种主要的生物碱,有很好的开发利用价值。     

莲品种资源的SRAP遗传多样性分析

利用分子标记SRAP技术对国内广泛栽培以及新近育成的39个莲品种进行了DNA多态性分析。选取5对引物扩增基因组DNA,共获得101条带,其中88条为多态性条带,每对引物平均提供20个标记信息。由UPMGA方法得到的聚类分析结果表明了39个品种间的遗传关系,结果表明:花莲、籽莲和藕莲三大类群有明显的界限,花莲和籽莲的遗传距离较近,藕莲与它们的遗传距离较远。分子方差分析结果表明:莲品种间和品种内均存在遗传变异,藕莲品种内的遗传变异略低于品种间的遗传变异,而诱变籽莲、诱变花莲和常规籽莲品种内遗传变异均大于品种间的遗传变异,尤其是诱变籽莲、诱变花莲品种内遗传变异占总变异的分量分别超过了70%和60%,这种品种内的遗传变异,一方面对于莲的高产稳产具有重要的意义,另一方面也说明了从这些国内广泛栽培的品种以及新近育成的莲品种中可以直接进一步选育出更优良的新品种。     

Genetic diversity and inferred ancestry of Asian lotus (Nelumbo nucifera) germplasms in Thailand and Vietnam

Tropical lotus (Nelumbo) is an important and unique ecological type of lotus germplasm. Understanding the genetic relationship and diversity of the tropical lotus is necessary for its sustainable conservation and utilization. Using 42 EST-SSR (expressed sequence tag-simple sequence repeats) and 30 SRAP (sequence-related amplified polymorphism) markers, we assessed the genetic diversity and inferred the ancestry of representative tropical lotus from Thailand and Vietnam. In total, 164 and 41 polymorphic bands were detected in 69 accessions by 36 EST-SSR and seven SRAP makers, respectively. Higher genetic diversity was revealed in Thai lotus than in Vietnamese lotus. A Neighbor-Joining tree of five main clusters was constructed using combined EST-SSR and SRAP markers. Cluster I included 17 accessions of Thai lotus; cluster II contained three Thai accessions and 11 accessions from southern Vietnam; and cluster III was constituted by 13 accessions of seed lotus. Consistent with the results from the Neighbor-Joining tree, the genetic structure analysis showed that the genetic background of most Thai and Vietnamese lotus was pure, as artificial breeding has been rare in both countries. Furthermore, these analyses indicate that Thai and Vietnamese lotus germplasms belong to two different gene pools or populations. Most lotus accessions are genetically related to geographical distribution patterns in Thailand or Vietnam. Our findings showed that the origin or genetic relationships of some unidentified lotus sources can be evaluated by comparing morphological characteristics and the data of molecular markers. In addition, these findings provide reliable information for the targeted conservation of tropical lotus and parent selection in breeding novel cultivars of lotus.     

荷花反季节栽培技术试验

在可调控温湿度的薄膜温室大棚内,采用‘冬花红’（冬荷）、‘蝶恋花’、‘香雪海’3个荷花品种进行反季节栽培试验,摸索出一套适合东莞地区的荷花反季节栽培技术,并于12月初成功培育出盛开的荷花,实现夏荷冬开、延长荷花观赏期的目的。     

HP-20树脂分离与纯化荷叶黄酮的技术研究

荷叶黄酮是荷叶中的主要活性成分之一,主要为黄酮醇和黄酮苷类,成为现代健康产品研究开发的热点。试验以高含量的荷叶黄酮为样品,比较X-5、HP-20,NKA、AB-8及HPD-100几种大孔吸附树脂的吸附效果,结果显示HP-20分离效果最好,静态饱和吸附量可达68.90 mg/g树脂,解吸率达87.23%,动态饱和吸附7 mg/mL的荷叶黄酮的料液可达15 BV。系统优化了HP-20树脂柱分离纯化用70%的乙醇提取的荷叶醇提物,得到荷叶黄酮的分离纯化的技术参数。结果表明:上样浓度为200 mg/mL,流速为2 BV/h的洗脱速度时,40%的乙醇对荷叶黄酮的洗脱能力较强,经过一次分离黄酮含量可达62.06%,此梯度黄酮的得率可达81.40%,荷叶黄酮的总得率为98.17%,经过再分离,荷叶黄酮含量可提高到98.87%。     

基于SSR标记的荷花品种遗传多样性及群体结构分析

采用SSR标记技术对42个荷花品种( Nelumbo spp.)的基因组DNA进行扩增,在此基础上,对供试品种进行UPGMA聚类分析、群体结构分析和主坐标分析( PCoA)。结果表明：采用17对SSR引物从42个荷花品种的基因组DNA中扩增出77个位点,多态性位点百分率为88.31%;每对引物可扩增出1~9个多态性位点。根据Nei's遗传距离,供试的42个荷花品种可被分成Ⅰ和Ⅱ两组,分别包含3和39个品种;在Nei's遗传距离0.150处,Ⅱ组被进一步分成Ⅱa、Ⅱb和Ⅱc 3个亚组,分别包含3、16和20个品种。群体结构分析结果表明：组分概率高于等于0.80时,供试的42个荷花品种被分成Pop1、Pop2和混合群3个亚群,分别包含17、16和9个品种。 PCoA分析结果表明：在F1水平上,供试的42个荷花品种被分成2个部分;其中,Pop1亚群的品种均分布在第二和第三象限,而Pop2亚群的品种则分布在第一和第四象限。总体来看,聚类分析、群体结构分析和PCoA分析的结果基本一致。综合分析结果表明：玉组包含美洲黄莲( N. lutea Pers.)品种‘艾江南',且与传统中国莲( N. nucifera Gaertn.)品种的亲缘关系最远,故认为该组为美洲黄莲;Ⅱ组为中国莲,其中,Ⅱc亚组以传统中国莲品种为主,而Ⅱb亚组则偏重于美洲黄莲。总体上看,供试的42个荷花品种主要被分为中国莲和美洲黄莲两组,而中美杂交莲并没有独立成组,其成因有待进一步研究。     

RAPD Analysis of Germplasm in Ancient

By using 40 random primers and 8 anchor-SSR primers, RAPD and microsatellite DNA (SSR) polymorphism were detected in the ancient "Taizi lotus" and the modem Chinese red flower lotus (Nelumbo nucifera Gaertn. ) from Hebei, Harbin (wild population), Jiangxi and Hunan (cultivar). The polymorphism information could be provided with 13 random primers and 2 SSR primers. Total 135 loci were amplified, 71 loci of these were polymorphic (53%). Agarose electrophoresis showed high genetic identity without any genetic variation whithin "Taizi" and Harbin lotus by using the above-mentioned 15 primers. However, there were different extent of differentiation within Hebei, Jiangxi and Hunan lotus. According to the UPGMA analysis of MEGA program, "Taizi", Harbin and Hebei lotus were gathered to a branch in the dendrogram. The genetic distance of "Taizi" and Hebei lotus were very close (0.05). They shared a common ancestry. Comparing with the modem Chinese lotus ( N. nucifera ), the ancient "Taizi" lotus only lacked one locusOPM06-300, so it still belonged to N. nucifera. Hunan and Jiangxi lotus were close to gather and could be grouped in another branch. Their genetic distances from the ancient "Taizi" lotus were farthest (0.67).     

镉在莲各器官中累积规律的研究

莲子是我国重要的特产优质资源,但莲等水生植物容易吸收积累重金属.为了探究莲对重金属镉的吸收积累特点,利用盆栽外施不同浓度的镉(0,1.0 mg·kg-1,2.5 mg·kg-1)培养两个莲子品种,检测分析镉对莲子生物量的影响及莲各器官中镉的含量.结果表明:随着外施镉浓度的增加,两种莲子生物量下降,各器官中镉含量增加,且...     

荷花品种比较试验

从始蕾、始花期、群体花期、着花密度、株型、花型等方面对41个荷花品种进行比较试验。结果表明,大株型荷花品种以祝福、西湖红莲最好;中小株型以金珠落玉盘、小精灵、绿云、小碧台、玉碗、红宝石、醉半熏、淡云、雨花、桃红小碗、红碗莲、瑶池春暖等12个品种最好,具有较高的观赏价值和商品价值。