甜瓜属植物抗根结线虫种质资源研究进展

根结线虫是危害甜瓜属栽培作物的重要病害之一,长期以来人们围绕抗根结线虫种质资源进行了多方面研究,本文就甜瓜属植物抗根结线虫种质资源鉴定、创新,抗根结线虫砧木,根结线虫抗性机理以及遗传规律研究进展进行了综述.     

红麻种质资源根结线虫病抗性鉴定

为鉴定我国红麻种质资源对根结线虫病的抗病性,在对120份红麻遗传资源进行田间自然发病鉴定的基础上,选择25份有代表性(22份高抗和3份感病)的种质进行盆栽根结线虫病接种鉴定。田间自然发病鉴定结果:120份红麻遗传资源中5个高感、19个中感、25个中抗、71个高抗;其侵染的根结线虫主要为南方根结线虫(Meloidogyne incognita)、爪哇根结线虫(Meloidogyne javanica)和花生根结线虫(Meloidogyne arenria)的混合种群。进行盆栽接种鉴定的25份遗传资源中,7份为中抗,其余分别为中感和高感品种,未发现高抗或免疫品种。本研究可为红麻种质资源发掘利用提供科学依据。     

不同葫芦科作物对二斑叶螨的抗性评价

【目的】二斑叶螨Tetranychus urticae Koch是世界性重大农业害螨,葫芦科作物是其重要寄主植物。为明确不同葫芦科作物对二斑叶螨生长发育的抗性/适合性,开展了二斑叶螨在葫芦科作物上的产卵和取食选择性研究。【方法】选择苦瓜、葫芦、南瓜、丝瓜、西瓜、甜瓜和黄瓜作为供试寄主植物,室内采用离体叶片和室外采用活体植株比较了二斑叶螨对7种作物的取食选择性及其种群生存与繁殖动态。【结果】供试7种葫芦科作物中,二斑叶螨对黄瓜的选择率最高,为35.49%,其次为甜瓜和西瓜;二斑叶螨在南瓜和黄瓜叶碟上的生存率和繁殖率高,12 h单雌产卵数分别为9.72粒和7.83粒;在葫芦和苦瓜叶碟上,二斑叶螨48 h螨口减退率达47.5%和32.5%,表现为较低的取食和生存适合度,同时葫芦和苦瓜活体植株上二斑叶螨繁殖率显著低于其他5种葫芦科作物。【结论】二斑叶螨在黄瓜、西瓜和甜瓜上的种群发育适合度高,在葫芦和苦瓜上适合度低。这一结果可为田间防控二斑叶螨生态措施的制定及开展葫芦科作物抗螨性机理和抗螨育种提供科学依据。     

节瓜及近缘葫芦科作物种质资源rDNA-ITS序列分析与系统进化研究

通过PCR扩增获得了56份节瓜种质资源及7份相关瓜类种质资源的rDNA-ITS序列,测序后结合GenBank中34份葫芦科作物的ITS序列,利用生物信息学软件分析序列长度、变异位点、G+C含量、遗传分歧、同源性百分比差异、系统进化关系。节瓜种质资源ITS基本序列全长612~617 bp,G+C含量59.97%~61.07%,供试材料间共96个变异位点,其中一些变异位点有明显的种性特征,可作为特异DNA指纹鉴别位点。基于ITS序列差异,56份节瓜材料聚为5大类,其中12-2-3材料为单独一个分支,黑毛节瓜H2251为第二分支,H5FA为第三分支,剩余节瓜材料聚为第四、五分支。节瓜材料12-2-3与其他材料遗传分歧最大,农艺性状与抗性也差异较大,可用作节瓜杂交育种的亲本以扩大选择范围。节瓜的系统位置排列在Indomelothria blumei(GU799496)与Dactyliandra welwitschii(HQ201973)之间,与Indomelothria blumei亲缘关系最近;Mrbayes软件分析表明,葫芦科作物Zehneria thwaitesii(AM981145)、Ctenolepis cerasiformis(AM981142)、Cucumis melo(AM36377)、Dactyliandra welwitschii(HQ201973)、Trochomeria macrocarpa(AM981141)最原始,系统进化顺序为甜瓜→南瓜、栝楼、苦瓜、丝瓜、西瓜、蒲瓜→冬瓜、节瓜→黄瓜。本研究通过分析节瓜及近缘葫芦科作物种质资源的ITS序列,为其系统进化、DNA指纹鉴别、育种亲本选择及比较组学分析等提供了分子生物学依据。     

黄瓜资源对黄瓜绿斑驳病毒广东分离物的抗性水平鉴定

【背景】黄瓜绿斑驳花叶病毒(Cucumber green mottle mosaic virus,CGMMV)是严重威胁葫芦科作物生产的毁灭性病原之一,该病毒已入侵我国十多个省份,危害西瓜、黄瓜等作物并造成严重的经济损失。早在2009年广东即发现CGMMV为害西瓜和黄瓜,但黄瓜等葫芦科作物对其抗性情况尚不清楚。【方法】采用人工机械摩擦接种方法,测定了14份黄瓜种质资源对CGMMV广东分离物的抗性水平。【结果】从广东葫芦病样中分离获得CGMMV,该病毒分离物MP基因序列与国内报道的各分离物同源率均在99%以上;14份黄瓜种质资源对该病毒分离物均表现为感病。【结论与意义】广东主要黄瓜资源对CGMMV均表现为感病,这为我省防控该病毒病提供了科学依据,也为黄瓜抗病育种提供了指导。     

海南岛象耳豆根结线虫的种类鉴定及其rDNA ITS序列分析

【背景】植物根结线虫病是世界性分布的土传病害,常造成农作物的重大经济损失。目前分布于热带亚热带区域的象耳豆根结线虫,由于其致病性和分子特征以及与植物互作关系的独特性,被认为是一种对农作物具有潜在危害性的重要病原根结线虫,因而引起国内外植物寄生线虫学者的广泛关注。【方法】用形态学、同工酶技术和分子生物学技术相结合的方法,对从海南岛农作物上采集到的10个根结线虫纯化种群进行分类鉴定。【结果】象耳豆根结线虫在海南岛大面积栽培的10种农作物和南药植物,包括黄瓜、南瓜、苦瓜、丝瓜、葫芦瓜、辣椒、番石榴、海巴戟、沈香和丁香上均有寄生,其形态学、酯酶表型和mtDNA PCR扩增产物均有别于常见的根结线虫种类;用引物18S和28S扩增象耳豆根结线虫种群的rDNA ITS区序列,并对其进行克隆、测序和比对分析,结果表明,象耳豆根结线虫4HBJ种群分别与南方根结线虫、爪哇根结线虫和花生根结线虫的同源性均仅为88%左右。【结论与意义】本文准确鉴定了象耳豆根结线虫,首次阐述其对海南岛多种农作物的致害性;阐释了象耳豆根结线虫的形态和分子特征,并明确了其与3种常见根结线虫的系统发育关系。本研究对今后进一步开展象耳豆根结线虫的基础研究和防治工作具有重要参考价值。     

海南岛象耳豆根结线虫的种类鉴定及其rDNA-ITS序列分析

【背景】植物根结线虫病是世界性分布的土传病害,常造成农作物的重大经济损失。目前分布于热带亚热带区域的象耳豆根结线虫,由于其致病性和分子特征以及与植物互作关系的独特性,被认为是一种对农作物具有潜在危害性的重要病原根结线虫,因而引起国内外植物寄生线虫学者的广泛关注。【方法】用形态学、同工酶技术和分子生物学技术相结合的方法,对从海南岛农作物上采集到的10个根结线虫纯化种群进行分类鉴定。【结果】象耳豆根结线虫在海南岛大面积栽培的10种农作物和南药植物,包括黄瓜、南瓜、苦瓜、丝瓜、葫芦瓜、辣椒、番石榴、海巴戟、沈香和丁香上均有寄生,其形态学、酯酶表型和mtDNA-PCR扩增产物均有别于常见的根结线虫种类;用引物18S和28S扩增象耳豆根结线虫种群的rDNA-ITS区序列,并对其进行克隆、测序和比对分析,结果表明,象耳豆根结线虫4HBJ种群分别与南方根结线虫、爪哇根结线虫和花生根结线虫的同源性均仅为88%左右。【结论与意义】本文准确鉴定了象耳豆根结线虫,首次阐述其对海南岛多种农作物的致害性;阐释了象耳豆根结线虫的形态和分子特征,并明确了其与3种常见根结线虫的系统发育关系。本研究对今后进一步开展象耳豆根结线虫的基础研究和防治工作具有重要参考价值。     

玉米种质资源对六种重要病虫害的抗性鉴定与评价

在2003－2005年间,对604份玉米种质进行了抗弯孢菌叶斑病和玉米螟鉴定,筛选出抗弯孢菌叶斑病的材料93份,抗玉米螟材料22份。2006－2009年间,对836份玉米种质进行了抗大斑病、茎腐病、穗腐病和瘤黑粉病的鉴定与评价,筛选出一批高抗和多抗的资源。在836份资源中,对大斑病1、2和N号3个生理小种具有抗性的材料均为50％左右;抗茎腐病材料为41.3％,高抗和抗性种质分别为264和81份;穗腐病高抗和抗性种质分别为5和171份,占比为21.1％;瘤黑粉病高抗和抗性种质各261和14份,占总鉴定材料的32.9％。上述结果表明抗大斑病、茎腐病和瘤黑粉病的种质资源较为丰富。通过对抗性结果进行对比分析,发现不同生态区玉米种质的抗性强弱以及抗性多样性存在明显差异,黑龙江和内蒙的种质对病虫害的抗性强弱及多样性程度明显高于四川种质。此外,玉米自交系对病虫害的抗性强弱以及多抗性程度高于农家种。     

玉米种质资源对六种重要病虫害的抗性鉴定与评价

在2003-2005年间,对604份玉米种质进行了抗弯孢菌叶斑病和玉米螟鉴定,筛选出抗弯孢菌叶斑病的材料93份,抗玉米螟材料22份。2006-2009年间,对836份玉米种质进行了抗大斑病、茎腐病、穗腐病和瘤黑粉病的鉴定与评价,筛选出一批高抗和多抗的资源。在836份资源中,对大斑病1、2和N号3个生理小种具有抗性的材料均为50%左右;抗茎腐病材料为41.3%,高抗和抗性种质分别为264和81份;穗腐病高抗和抗性种质分别为5和171份,占比为21.1%;瘤黑粉病高抗和抗性种质各261和14份,占总鉴定材料的32.9%。上述结果表明抗大斑病、茎腐病和瘤黑粉病的种质资源较为丰富。通过对抗性结果进行对比分析,发现不同生态区玉米种质的抗性强弱以及抗性多样性存在明显差异,黑龙江和内蒙古的种质对病虫害的抗性强弱及多样性程度明显高于四川种质。此外,玉米自交系对病虫害的抗性强弱以及多抗性程度高于农家种。     

不同薄皮甜瓜种质白粉病抗性研究

本研究采用田间自然鉴定和离体叶片接种鉴定的方法,研究了7个薄皮甜瓜种质对白粉病的抗性,并分析了气孔大小、气孔密度和叶绿素含量与白粉病抗性的关系。结果表明,离体叶片接种鉴定和田间自然鉴定的白粉病抗性结果一致,共鉴定出5个抗病种质,2个感病种质,四倍体的抗病性优于二倍体;气孔大小和叶绿素含量与病情指数呈负相关,气孔密度与病情指数呈正相关,除气孔大小与离体鉴定病情指数呈显著性相关外,其它指标与病情指数相关性不显著,抗病种质和感病种质在气孔大小、气孔密度和叶绿素含量上差异均不显著,因此,气孔大小、气孔密度和叶绿素含量与薄皮甜瓜白粉病抗性不相关。     

南亚果实蝇对六种果实的趋性和产卵选择性

南亚果实蝇Bactroceratau(Walker)是危害黄瓜、南瓜、冬瓜、丝瓜和苦瓜等果蔬作物的一种重要检疫性害虫。趋性反应和产卵选择性实验结果表明,该虫对不同的果实切片具有不同的趋性和产卵选择性。在黄瓜、南瓜和丝瓜上,成虫的落虫数量分别占落虫总量的23.68%,19.94%和21.18%,产卵量分别占产卵总量的21.57%,18.93%和22.74%,均高于其它3种果实冬瓜、苦瓜和柑橘上落虫数和产卵量。幼虫在黄瓜、南瓜和丝瓜上取食的数量亦较高,分别占幼虫总量的23.33%,31.44%和21.67%;而在柑橘上仅占幼虫总量的2.22%。成虫和幼虫均对受害与未受害果实的趋性和选择性表现出一定的差异,总体上在受害果实上的虫口数量较多,而在未受害果实上的数量较少。因此,在这6种寄主植物中,南亚果实蝇喜好在黄瓜、南瓜和丝瓜以及受害的果实上获得补充营养或产卵。     

食料对南亚果实蝇解毒酶活力的影响

昆虫解毒酶是一类异质酶系, 对分解大量的内源或外源有毒物质、维持正常生理代谢起着重要作用。本文采用生物化学的方法测定了5种寄主果实对南亚果实蝇Bactrocera tau Walker 3个虫态体内总蛋白含量和5种解毒酶的活力。双因子方差分析显示, 南亚果实蝇种群取食黄瓜Cucumis sativus L.、南瓜Cucurbita moschala L.、丝瓜Luffa cylindrical L.、冬瓜Benincasa hispida (Thunb.) Coqn.和苦瓜Momordica charantia L.后, 体内蛋白含量和解毒酶活性均存在显著差异。以丝瓜为食料时, 南亚果实蝇体内蛋白含量较高; 而以黄瓜和冬瓜为食料时蛋白含量则相对较低。在以上5种寄主果实间, 南亚果实蝇的羧酸酯酶（CarE）活性在黄瓜和南瓜上较高, 细胞色素P450 O-脱甲基和谷胱甘肽S-转移酶（GST）活性在苦瓜上较高, 酸性磷酸酯酶（ACP）和碱性磷酸酯酶（ALP）活性却分别在黄瓜和南瓜上较低。在幼虫、蛹和成虫3个虫态间, 解毒酶活性亦存在显著差异, 成虫具有较高的CarE活性;幼虫具有较高的细胞色素P450 O-脱甲基, GST和ALP活性,但具有较低的ACP活性;除ACP外,蛹期解毒酶活性均较低。据以上结果可以推测,南亚果实蝇解毒酶活力受寄主果实种类以及该种群本身发育阶段的影响。     

Resistance in melon to Monosporascus cannonballus and M. eutypoides: Fungal pathogens associated with Monosporascus root rot and vine decline

The fungal species Monosporascus cannonballus and M. eutypoides have been described as the causal agents of Monosporascus root rot and vine decline disease (MRRVD), which mainly affects melon and watermelon crops. Resistance to M. cannonballus has been reported in some melon cultivars (ssp. melo). Moreover, melon ssp. agrestis accessions have proven to be better resistance sources. This is the case of the Korean accession ‘Pat 81’, highly resistant under field and artificial inoculation. The objective of the work here presented was the evaluation of the resistance to MRRVD of different accessions representing the variability of Cucumis melo ssp. agrestis, against both, M. cannonballus and M. eutypoides, in a multiyear assay under different infection conditions. In general, M. eutypoides was less aggressive than M. cannonballus in the different environmental conditions. There was a strong influence of temperature on MRRVD, with more severe symptoms with higher temperatures and with variable effect of infection on plant development depending on the fungal species considered. Resistance to MRRVD has been confirmed in ‘Pat 81’ and in its derived F1 with a susceptible Piel de Sapo melon. Among the new germplasm explored, African accessions (both wild agrestis and exotic cultivated acidulus) showed good performance in artificial inoculation assays and in field conditions. These sources do not present compatibility problems with commercial melons, so they can be introduced in backcrossing programs. The accession assayed of the wild relative Cucumis metuliferus, also resistant to Fusarium wilt and to root-knot nematode, was highly resistant to MRRVD. The interest of this accession mainly relies in its advantages as a rootstock for melon.     

The cucurbit images (1515-1518) of the Villa Farnesina, Rome

BACKGROUND: The gorgeous frescoes organized by the master Renaissance painter Raphael Sanzio (1483-1520) and illustrating the heavenly adventures of Cupid and Psyche were painted between 1515 and 1518 to decorate the Roman villa (now known as the Villa Farnesina) of the wealthy Sienese banker Agostino Chigi (1466-1520). Surrounding these paintings are festoons of fruits, vegetables and flowers painted by Giovanni Martini da Udine (1487-1564), which include over 170 species of plants. A deconstruction and collation of the cucurbit images in the festoons makes it possible to evaluate the genetic diversity of cucurbits in Renaissance Italy 500 years ago. FINDINGS: The festoons contain six species of Old World cucurbits, Citrullus lanatus (watermelon), Cucumis melo (melon), Cucumis sativus (cucumber), Ecballium elaterium (squirting cucumber), Lagenaria siceraria (bottle gourd) and Momordica balsamina (balsam apple), and two or three species of New World cucurbits, Cucurbita maxima, C. pepo and, perhaps, C. moschata (pumpkin, squash, gourd). The images of C. maxima are the first illustrations of this species in Europe.     

Influence of different Inocula of Meloidogyne arenaria on plant growth parameters and nematode multiplication in balsam (Impatiens balsamina)

Pathogenic effect of root-knot nematode Meloidogyne arenaria was studied on balsam (Impatiens balsamina) by inoculating the different inoculum levels of root-knot nematode. It was observed that the inoculum levels up to 2000 J₂ of root-knot nematode did not show significant reduction in plant growth characters as compared to control. Although the significant reduction in plant growth characters was recorded at and above 3000 J₂ of root-knot nematode, progressive increase in the host infestation as indicated by the number of galls as well as the population of root-knot nematode was recorded with an increase in the level of inoculum. However, the rate of nematode multiplication was reduced with the increase in the inoculum density of M. arenaria. It can be concluded from these results that the damaging threshold level of M. arenaria on balsam was found to be as 3000 J₂/plant.     

Genetic analysis of Anatolian pear germplasm by simple sequence repeats

The pear (Pyrus communis L.) is a fruit species grown in many temperate regions of the world. Turkey harbours a rich and ancient pear germplasm adapted to diverse ecological regions of the country. The aim of this study was to genetically characterise locally grown Anatolian pear germplasm. We have analysed large numbers (228) of pear accessions originated from six eco‐geographically diverse regions using 18 simple sequence repeat (SSR) markers and identified 308 SSR alleles. Genetic similarities among the accessions examined were generally below 80%. The highest heterozygosity rate was obtained for the SSR locus ‘CH02D11’ derived from apples and ‘KA16’ and ‘NH0021a’ derived from pears. No identical or synonymous genotypes were found, while five homonymous genotypes were identified. Factorial correspondence analysis could not clearly separate different pear accession groups studied, suggesting that Anatolian pear accessions were intermixed possibly due to gene flow and/or germplasm movements between different eco‐geographical regions. However, most pear accessions were grouped according to their collection sites in structure analyses. The SSR data reported here for Anatolian pear accessions will be valuable for future germplasm management efforts as well as for comparative studies that investigate genetic relationships of pears from Anatolia and the surrounding regions.     

砧用瓠瓜抗枯萎病相关性及杂种优势分析

枯萎病是一种严重危害瓜类蔬菜生产的土传病害,嫁接栽培是防治瓜类枯萎病的有效方法。该文研究了砧用瓠瓜种质幼苗生长指标与抗病性的相关性,并对抗病杂种优势进行了分析。结果表明:(1)砧用瓠瓜种质H041对西瓜枯萎病表现高抗(HR),对瓠瓜枯萎病表现抗病(R),种质H01、H05和杂交组合H01×H041、H041×H05、H05×H041对两种枯萎病均表现抗病(R)。(2)砧用瓠瓜幼苗接种西瓜枯萎病菌后,病情指数与下胚轴粗度呈显著负相关;接种瓠瓜枯萎病菌后,总根长、根系表面积与病情指数呈极显著负相关,表明砧用瓠瓜对枯萎病的抗病性与根系生长具有相关性,可以根据根系生长情况快速评价砧用瓠瓜对瓠瓜枯萎病的抗性表现。(3)分析砧用瓠瓜杂交组合的抗病性杂种优势显示,供试杂交组合H05×H041对西瓜枯萎病具备超中亲优势;杂交组合H01×H041和H02×H041对瓠瓜枯萎病抗性具有负向杂种优势。综合研究结果发现,种质H01、H041、H05兼抗西瓜枯萎病和瓠瓜枯萎病,且配制出的杂交组合表现抗性杂种优势,可作为选育抗两种枯萎病的砧木或栽培品种的抗源亲本,其中H041可作为优势骨干亲本。     

Genetic Diversity and Population Structure of Cucumber (Cucumis sativus L.)

Knowing the extent and structure of genetic variation in germplasm collections is essential for the conservation and utilization of biodiversity in cultivated plants. Cucumber is the fourth most important vegetable crop worldwide and is a model system for other Cucurbitaceae, a family that also includes melon, watermelon, pumpkin and squash. Previous isozyme studies revealed a low genetic diversity in cucumber, but detailed insights into the crop''s genetic structure and diversity are largely missing. We have fingerprinted 3,342 accessions from the Chinese, Dutch and U.S. cucumber collections with 23 highly polymorphic Simple Sequence Repeat (SSR) markers evenly distributed in the genome. The data reveal three distinct populations, largely corresponding to three geographic regions. Population 1 corresponds to germplasm from China, except for the unique semi-wild landraces found in Xishuangbanna in Southwest China and East Asia; population 2 to Europe, America, and Central and West Asia; and population 3 to India and Xishuangbanna. Admixtures were also detected, reflecting hybridization and migration events between the populations. The genetic background of the Indian germplasm is heterogeneous, indicating that the Indian cucumbers maintain a large proportion of the genetic diversity and that only a small fraction was introduced to other parts of the world. Subsequently, we defined a core collection consisting of 115 accessions and capturing over 77% of the SSR alleles. Insight into the genetic structure of cucumber will help developing appropriate conservation strategies and provides a basis for population-level genome sequencing in cucumber.     

植物果实、颜色和形状对橘小实蝇产卵选择的影响

橘小实蝇Bactrocera dorsalis(Hendel)是近几年入侵江苏南部地区,严重危害当地水果、蔬菜的重要害虫。为深入了解其在该地区果树、蔬菜上的产卵特性,进行植物果实、颜色和形状对其产卵选择影响的研究。实验室中"纸杯法"的产卵选择试验结果表明,橘小实蝇对不同水果的产卵偏好性由高到低依次为:柑橘、香蕉、芒果、枣、石榴、苹果、桃子、梨、李、葡萄、柿;对不同蔬菜的产卵偏好性由高到低依次为:丝瓜、豇豆、苦瓜、黄瓜、茄子、南瓜、青椒、番茄。对不同寄主颜色和形状的产卵选择特点为,雌虫常选择桔黄色、绿色,以及圆球形的寄主产卵,而较少选择黑色、方形的寄主产卵。从试验结果可以看出,寄主果实散发出的气味,及其颜色和形状对橘小实蝇的产卵选择有影响。