菜用大豆品种资源对大豆花叶病毒病的抗性评价

对40个供试菜用大豆品种进行了抗2个SMV流行株系的鉴定。结果表明,有4个品种抗SC-3株系,分别是‘苏鲜4号’、‘浙鲜豆5号’、‘奎丰4号’和‘KVS124’;‘浙农8号’和‘苏鲜4号’抗SC-7株系,‘苏鲜4号’兼抗SC-3和SC-7株系。这些品种可作为抗源用于抗病品种选育和与抗性遗传相关的研究。此外,还鉴定筛选出‘通豆6号’、‘青酥2号’、‘青酥4号’、‘青酥5号’和‘青酥6号’等5个品种对SMV的主要流行株系SC-3表现耐病,这些品种可直接用于菜用大豆的生产。研究还显示,来自江苏地区的育成品种抗性相对较好,而来自上海崇明的地方大豆品种资源抗性普遍较差,这可能与该地区流行的SMV株系的类型相关。     

Breeding for resistance: breeding for resistance to Plum pox virus in Italy

Plum pox virus (PPV) resistance in apricot and peach in Italy has been researched in several Italian institutions, including the Institutes for Fruit Tree Culture and Plant Pathology in Rome, which are assessing resistance, and the Universities of Bari, Bologna and Milan, examining breeding techniques, both by cross-breeding and genetic transformation approaches. A reliable protocol for resistance assessment has been set up, in which biological indexing, ELISA and PCR techniques are used. No source of resistance has yet been found in peach. Hybridization with Prunus davidiana could be investigated given the promising results obtained within the INRA programme in France. Almost 6000 apricot seedlings from controlled crosses between resistant parents have been investigated in search of possible molecular markers, but no positive results have been obtained so far, probably due the fact that resistance to both D and M strains is sought. The transformation of cultivars has proven difficult in apricot where the regeneration step is particularly critical, while in peach a reliable regeneration protocol still remains to be set up.     

A recessive resistance gene of alfalfa to alfalfa mosaic virus and impact of high ambient temperature on virus resistance

Twenty plants of alfalfa cv. Beaver were screened for resistance to alfalfa mosaic virus (AIMV) severe strain A-515. ELISA screening on both inoculated and apical leaves at fixed temperature (20°C day, 16°C night) suggested the following three types of clonal response to AIMV infection: extremely resistant, AIMV not normally detected from either inoculated or apical leaves; resistant, AIMV detected from inoculated leaves only and did not spread systemically; susceptible, AIMV detected from both inoculated and apical leaves. When plants in the second category were maintained at high temperature (30°C), AIMV was detected from inoculated and apical leaves 6 and 12 days after inoculation, but was not detectable in the apical leaves thereafter. Plants in the first category remained extremely resistant at all temperatures tested. The results of comparative tests using progeny plants of extremely resistant, resistant and susceptible plants, and of their hybrids, suggested that the resistance to AIMV A-515 was controlled by a temperature-dependent recessive gene.     

Genetics of resistance to beet western yellows virus in lettuce

Resistance to beet western yellows virus (BWYV) in the lettuce cultivars Burse 17 and Crystal Heart was controlled by a single recessive gene designated bwy. ELISA tests showed that resistant plants were not immune to infection by BWYV, and may develop some mild symptoms. However, the concentration of virus found in resistant plants was less than in susceptible ones. The cultivar Crystal Heart is being used as a source of resistance for breeding BWYV-resistant crisp lettuce (iceberg) cultivars.     

Investigating resistance to Barley mild mosaic virus

There are claims that at least 11 genes confer resistance in barley ( Hordeum vulgaris ) to one or more components of the soilborne barley mosaic virus complex but, apart from the immunity conferred by the widely used gene rym4 , little is known about their mode of action. This study used mechanical (sap) and plasmodiophorid vector-inoculation techniques combined with ELISA, RT-PCR, symptom development and virus transmission to investigate the response of different genotypes to Barley mild mosaic virus (BaMMV). Barley genotypes were grown at 20 and 12°C to test for temperature sensitivity. Plants with the genes rym3 or rym6 were fully susceptible to the virus, whereas those with genes rym1 , Rym2 , rym5 or rym11 appeared to be immune, as BaMMV was never detected in any tissue type nor was the virus transmitted from them to susceptible genotypes. The remaining genotypes could all be infected to some extent by BaMMV using one or both inoculation methods, and virus could be transmitted from their roots by the plasmodiophorid vector Polymyxa graminis . Plants with the rym7 gene had delayed symptoms compared to susceptible controls at 12°C. Plants with the rym8 gene could be infected by both inoculation methods, but there was no virus in the leaves at 12°C. Plants with the rym9 gene could be infected only by vector inoculation, and virus remained localized in the roots. Plants with the rym10 gene appeared susceptible by mechanical inoculation at both temperatures, but after vector inoculation virus moved to leaves only at 20°C. This suggests the operation of translocation resistance in plants with the rym8 , rym9 or rym10 genes, which is temperature-sensitive in rym8 and rym10 and perhaps tissue-specific in rym9 . No resistance to P. graminis was observed in any of the genotypes.     

烟草品种对烟草花叶病毒病和黄瓜花叶病毒病的抗性鉴定

由烟草普通花叶病毒(TMV)和烟草黄瓜花叶病毒(CMV)引致的烟草病毒病是世界烟草主产区普遍发生且危害严重的侵染性病害,每年给烟叶生产造成了重大的经济损失。本文采用温室苗期接种鉴定的方法,对16份烟草种质进行了TMV和CMV的抗病性鉴定。结果表明:不同的烟草品种对TMV和CMV的抗病性存在较大差异。在供试种质中,对TMV表现免疫的有‘牛耳烟’、‘8301’、‘台烟7号’、‘三生-NN’共4份材料;表现抗病的有‘吉烟5号’、‘双抗70’、‘大护脖香’、‘秦烟95’共4份材料;表现中抗的有‘铁把子’、‘中烟15’、‘秦烟98’、‘中烟98’共4份材料;表现中感的有‘NC89’、‘翠碧1号’、‘云烟97’共3份材料;表现感病的只有‘秦烟97’。对CMV表现中抗的材料有1份,是‘铁把子’;表现中感的有‘秦烟95’、‘三生-NN’、‘8301’、‘牛耳烟’、‘翠碧1号’共5份材料;表现感病的有‘秦烟98’、‘云烟97’、‘中烟98’、‘NC89’、‘大护脖香’、‘双抗70’、‘秦烟97’、‘中烟15’、‘台烟7号’、‘吉烟5号’共10份材料。研究发现,‘铁把子’是兼抗这两种病毒病的材料。本研究明确了我国16个烟草品种资源的抗病性水平,为抗耐病品种的利用与品种合理布局提供科学依据,同时为烟草抗病毒病育种的亲本选择提供抗源信息。     

Genetic aspects of polyacrylic-acid-induced resistance to tobacco mosaic virus and tobacco necrosis virus in Nicotiana plants

Among the Nicotiana tabacum cultivars and hybrids tested, polyacrylic acid (PAA) only induced resistance to tobacco mosaic virus (TMV) and tobacco necrosis virus (TNV) in the cultivars Xanthi-nc (NN) and Xanthi (nn) respectively. This varietal response to the PAA treatment could be sexually transmitted. The complete genetic analysis of the inheritance of the PAA response is reported for the first time, demonstrating that the response is a dominant character with a Mendelian segregation which occurs independently of either the N gene responsible for resistance to TMV or the PRb-protein genes. Possible relationships between the N gene, the gene for the PAA response and the PRb genes are discussed.     

玉米粗缩病抗性遗传研究

 本文选用3个抗病自交系(齐319、X178、沈137)和3个感病自交系(掖107、掖478、沈5003)按照NCII交配设计配制9套杂交组合研究了玉米抗粗缩病遗传规律。2009-2010年在曲阳、保定采用田间自然发病方法鉴定亲本、F₁、F₂群体的玉米粗缩病抗性,并采用灰飞虱人工接种方法鉴定亲本材料的抗病性。运用QGA station 软件的加性-显性-上位性(ADAA)遗传模型进行数据分析,结果表明,显性效应和加性效应是控制玉米粗缩病抗性的主要遗传组分,分别占表型变异的44.8%和13.1%,杂合显性效应表现负向杂种优势,抗病育种可加以利用。加性×加性上位性效应在玉米自交系和杂交组合抗粗缩病遗传中普遍存在,但因材料不同而表现负向或正向效应。玉米粗缩病抗性易受环境影响,显性与环境互作效应方差占表型方差的比率为39.8%,达到极显著水平。因此,培育抗粗缩病玉米品种应依据基因型选配适当的亲本材料,抗病品种宜进行多年多点鉴定筛选。     

Potato virus X (PVX) resistance in tomato cultivars

Understanding how birds detect and react to deterrent methods which are employed to protect structures is important both for the effective control of property damage, and to ensure that human health and safety are not compromised. One such device is a shock strip that causes slight pain to birds when they use a perch. Our aims were to determine: (1) the efficacy of a shock strip to flocks of Brown-headed Cowbirds (Molothrus ater), and Rock Pigeons (Columba livia); (2) the length of time to extinction of effect; (3) whether members of a flock show a behavioural response to treatment; and (4) whether the birds habituate to the treatment. When activated, shock strips were effective in displacing birds from treated areas. Birds had to experience the treatment; there was no discernible indication of flock members reacting to affected birds. When strips were deactivated after an initial period of activation, birds required more than 2 hours to return to treated areas. No habituation was observed. Because birds had to experience the shock, reduced coverage of a structure or use of sham devices to lower costs is considered inadvisable.     

大白菜抗芜菁花叶病毒的QTL分析

 以大白菜高抗TuMV-C₃株系的高代自交系A52-2和感病自交系GCⅣ杂交的F₂代255个单株作为构建遗传图谱的作图群体,通过EST-PCR-RFLP和AFLP分子标记的遗传分析,构建了包含12个连锁群,由124个遗传标记组成的大白菜分子遗传图谱。其中包括6个EST-PCR-RFLP多态性位点和118个AFLP多态性位点,该图谱覆盖长度为683.9 cM,平均图距5.52 cM。利用Windows QTL CartographerV 2.0软件和复合区间作图法进行分析,共检测到4个抗TuMV-C₃株系的QTLs位点。     

Studies on lettuce mosaic virus resistance in commercial lettuce cultivars

The response to infection with lettuce mosaic virus (LMV) of 16 lettuce cultivars, known to possess the Momo gene for resistance to LMV, was studied in field trials over a 2-year period. Some cultivars developed negligible mosaic symptoms following virus inoculation and had a low virus content as measured by ELISA, while others had more severe symptoms and a higher virus content. Resistant cultivars differed significantly in the effect of LMV upon yield and the correlation between cultivar rankings for yield depression and symptom severity was low.     

hpRNA的茎环比例对RNA介导的病毒抗性产生的影响

 以马铃薯Y病毒坏死株系(PVY^N)的外壳蛋白(coat protein,CP)基因3'端50bp片段为hpRNA的茎,以pUC19不同长度的序列为hpRNA的环,构建了茎环比例分别为4:1、2:1、1:1、1:2、1:4和1:8的植物表达载体。利用农杆菌介导法转化烟草品种NC89,获得了多种转基因植株。室内抗病性检测发现:不同茎环比例的hpRNA介导的病毒抗性效率不同;茎环比例为4:1、2:1和1:1时效率较高,抗性植株的比例达60%左右;随着环长度的逐渐增加,抗性植株的比例逐渐降低;当茎环比例为1:8时,抗性植株的比例仅为9.52%。Southern blot分析结果表明:外源基因已整合于烟草的基因组中,且转基因植株的抗病性与转基因的拷贝数之间无明显的相关性。Northern blot分析结果表明:目的片段转录产物的积累量与植株的抗病性呈负相关,证明所获得的抗病性是RNA介导的。     

Partial resistance to Wheat dwarf virus in winter wheat cultivars

Four Hungarian winter wheat cultivars were investigated for their susceptibility to the geminivirus Wheat dwarf virus (WDV). Previously, two cultivars (Mv Regiment and Mv Emese) were assessed by breeders to exhibit virus symptoms in the field, whereas Mv Dalma and Mv Vekni showed few symptoms. Two inoculation techniques for WDV, vector transmission with the leafhopper Psammotettix alienus and agroinoculation, were used. Leafhopper transmission was more efficient than agroinoculation. However, irrespective of the technique used, no Mv Dalma or Mv Vekni plants showed clear WDV symptoms. In contrast, 3/30 Mv Emese and 4/36 Mv Regiment plants showed dwarfing and chlorosis after agroinoculation and 13/17 and 14/15 plants, respectively, had clear WDV symptoms after vector transmission. WDV‐specific PCR showed that Mv Vekni and Mv Dalma plants could be infected, especially following vector transmission (approximately 50% infection), but at significantly lower frequency than Mv Emese or Mv Regiment plants (100% infection). Furthermore, real‐time PCR showed that WDV DNA accumulated to much lower levels in infected Mv Vekni and Mv Dalma plants than in infected Mv Regiment and Mv Emese plants. The data strongly suggest that Mv Vekni and Mv Dalma are partially resistant to WDV infection. As WDV resistance has not previously been identified in wheat, and because WDV can cause significant yield losses, the resistance of Mv Vekni or Mv Dalma will provide a valuable breeding resource.     

Effect of temperature on resistance to Potato virus Y in potato cultivars carrying the resistance gene Rychc

The effect of cultivation temperatures on the resistance reaction to three Potato virus Y strains (PVY^O, PVY^N and PVY^NTN) in potato cultivars carrying Ry_chc was examined. When potato plants carrying Ry_chc were cultivated at 22 °C, a few small necrotic spots developed on inoculated leaves by 5 days after mechanical inoculation (dpi), and systemic infection of a few symptomless plants was confirmed at 28 dpi by IC‐RT‐PCR. At 28 °C, distinct necrotic spots developed on inoculated leaves by 5 dpi, and systemic symptoms occasionally appeared at 28 dpi. Thus, high temperature weakens Ry_chc‐conferred resistance. However, the incidence of systemic infection and the titre of virus in resistant cultivars at 28 °C were lower than in a susceptible cultivar. In graft inoculation under high summer temperatures, some plants developed necrosis on the leaves and stem, but PVY was barely detected by RT‐PCR in leaves on potato carrying Ry_chc. When seedlings from progeny tubers of plants that were inoculated with PVY and grown in a greenhouse at >30 °C in the daytime were examined by ELISA and IC‐RT‐PCR, PVY was not detected in cultivars carrying Ry_chc. These results show that Ry_chc confers an extreme resistance to PVY strains occurring in Japan.     

植物抗病毒的可能机制--基因沉默

根据目前RNA介导的植物病毒抗性(RMVR)、转录后基因沉默(PTGS)的研究成果,综述了基因沉默可能是植物抵抗病毒的一种机制,深入研究基因沉默不仅在抗病机制上有重要的理论意义,而且对彻底解决植物病毒问题有较大的潜在实用价值.     

Transmission attributes and resistance to rose rosette virus

Rosette caused by rose rosette virus (RRV) is a devastating disease of rose in the United States. The virus was discovered in 2011 and Koch's postulates completed in 2015. Because of these recent discoveries, assumptions about the disease including movement, transmission and resistance are based on visual observations of material that may or may not have been infected by the virus. This study addresses several aspects of virus and disease dynamics. Twenty rose genotypes were screened for mite and/or virus resistance. Phyllocoptes fructiphilus, the only known vector of RRV, was able to establish, lay eggs and develop nymphs and adults in all rose genotypes. Cultivar ‘Stormy Weather’ showed resistance to the virus as assessed in both mite and cleft‐grafting transmission experiments. Mites showed a long acquisition/latent period but a rapid inoculation time for RRV. Knowledge of resistance as well as transmission attributes will assist in better management of vector and disease. The identified resistant genotype would be used in areas with high disease pressure to minimize spread, for identification of the mechanisms behind resistance or as a breeding parent to incorporate virus resistance to new cultivars. The short inoculation access period suggests that chemical control for this vector may be challenging to undertake.     

Soilborne viruses: advances in virus movement,virus induced gene silencing,and engineered resistance

Until recently soilborne plant viruses were considered important only because they are causative agents for agricultural diseases. In recent years, soilborne plant viruses have played a significant role in advancing research into mechanisms of plasmodesmata transport, gene silencing, and engineered resistance to plant pathogens. Three different mechanisms by which viruses move through plasmodesmata have been identified using dianthoviruses, nepoviruses, and benyviruses. The infectious clone of the tobravirus Tobacco rattle virus (TRV) has become an important tool for studying virus induced gene silencing and may be a tool to silence meristematic gene expression. Investigations of soilborne viruses may enable the development of new strategies for control of soilborne diseases. The potential use of pathogen-derived resistance to control soilborne viruses is currently being explored in several laboratories.