甜椒脉斑驳病毒（PVMV）在海南的发现与检测

2014年在海南辣椒病毒病调查过程中发现了一种疑似病毒感染的辣椒样品,主要表现为叶片黄化、绿斑驳、叶脆易折断,且在田间发生较多。利用马铃薯Y病毒属的简并引物对其叶片总RNA进行RT-PCR检测,并将约1 700 bp目的片段克隆到pMD18-T载体上进行测序和BLAST分析。结果表明：该条带序列（包含部分NIb和部分cp基因）与已收录的甜椒脉斑驳病毒（Pepper veinal mottle virus,PVMV）（GenBank登录号：FM202327）序列相似性最高,达99％。设计cp基因的特异引物,对上述样品进行cp基因扩增并构建以cp基因序列为基础的系统进化树,发现海南辣椒上的PVMV与台湾的PVMV分离物ns1株同源性最高。田间检测结果表明：海南黄灯笼辣椒上PVMV的检出率高达74.07％,说明PVMV可能成为海南辣椒生产上的潜在威胁。     

Achievements and prospects in breeding for rhizomania resistance in sugar beet

Economic viability of a sugar beet crop largely depends on its successful protection against rhizomania, a most devastating disease that causes severe losses in root yield, sucrose content and quality. Rhizomania disease is caused by Beet necrotic yellow vein virus (BNYVV), a virus present in most sugar beet growing regions being vectored by the widely spread soil borne protoctist Polymyxa betae Keskin. The only practical means to control the disease is the use of genetically resistant varieties and, to date, such resistance is mainly based on a dominant gene (Rz1) that when present confers a sufficiently high level of protection against BNYVV. However, the emergence of virus strains capable of compromising the resistance employed in commercial varieties as well as a possible spread of more pathogenic isolates threatens crop's protection efficiency in the future. All these point to the necessity for exploiting new and more effective genetic sources of rhizomania resistance, both by classical and molecular breeding approaches, a practice that is being pursued by the relevant breeding firms. This article critically reviews the various issues related to the disease and its management and particularly to the ones pertaining to pathogen genetic diversity, types of genetic resistance currently employed, as well as to novel biotechnological approaches aiming at the development of better resisting cultivars.     

Effect of cyantraniliprole on feeding behavior and virus transmission of Frankliniella fusca and Frankliniella occidentalis (Thysanoptera: Thripidae) on Capsicum annuum

The anthranilic diamide insecticide cyantraniliprole was previously shown to reduce transmission of Tomato spotted wilt virus (TSWV) to pepper, Capsicum annuum, by Frankliniella fusca but not Frankliniella occidentalis. This study examines the effects of cyantraniliprole and imidacloprid on thrips feeding using electrical penetration graphing (EPG), and on TSWV transmission in field cage studies. Some antifeedant responses were observed in the EPG studies when thrips fed on cyantraniliprole- and imidacloprid-treated plants; however, these responses were variable between species and among the 2, 6, and 10 day post-treatment time intervals during which feeding behavior was observed. Cyantraniliprole significantly reduced the probability of TSWV infection when spread by F. fusca in field-grown pepper when viruliferous thrips were released 7 days but not when released at 14 days after the insecticide treatment in one of 2 field trials. In the second trial cyantraniliprole significantly reduced the probability of infection when F. fusca were released 14 days but not 7 days after treatment. In both years, imidacloprid prevented or significantly reduced transmission of TSWV by F. fusca in field-grown pepper when viruliferous thrips were released 7 days and 14 after treatment. In one of two years, cyantraniliprole significantly reduced the incidence of TSWV in field-grown pepper that was spread by F. occidentalis when viruliferous thrips were released 7 days after the insecticide treatment, but not 14 days after the treatment. Imidacloprid did not reduce the incidence of TSWV in field-grown pepper when viruliferous F. occidentalis were released. Although these studies demonstrate that probing behavior of these thrips species is altered on cyantraniliprole-treated pepper plants, results of field cage studies did not consistently show a reduction in incidence of TSWV-infected plants.     

Host suitability of peppers to the false root-knot nematode Nacobbus aberrans

The false root-knot nematode, Nacobbus aberrans, causes severe damage to field and greenhouse pepper crops in several localities of the American continent. No commercial peppers (Capsicum annuum) resistant to this nematode are available up to the present. Host suitability of 6 experimental and 3 commercial peppers (some of them carrying Me1 and Me7 resistance genes to Meloidogyne spp.) to two N. aberrans populations were evaluated under greenhouse experiments. None of the peppers was found to be resistant to the nematode. The evaluated parameters exhibited significant differences among some peppers tested within a single population and between populations for a single plant material. Some peppers carrying resistance showed higher nematode reproduction than some lines that did not possess resistance genes. These results confirmed that the genes conferring resistance to Meloidogyne spp. do not provide protection against this species of root-galling nematode. Host suitability of pepper lines carrying Me1 or Me7 resistance genes against N. aberrans is evaluated for the first time. Search for resistant genes against this nematode in wild peppers growing in areas where this nematode is indigenous should be promoted.     

Efficacy of composting infected plant residues in reducing the viability of Pepper mild mottle virus, Melon necrotic spot virus and its vector,the soil-borne fungus Olpidium bornovanus

Survival of Pepper mild mottle virus (PMMV) and Melon necrotic spot virus (MNSV) in diseased plant residues of pepper and melon, respectively, was studied in several experiments investigating drying and composting conducted in experimental heaps. The viability of the soil-borne fungus Olpidium bornovanus, the vector of MNSV, in infected melon root residues was also evaluated. Maximum temperatures in the heap reached 61.9–73.8 °C during composting processes. Drying of plant residues reduced the infectivity of MNSV whereas the infectivity of PMMV and O. bornovanus was unaffected by drying. Neither the virus nor the fungus was viable after composting. PMMV antigens where detected by serology after 30 and 60 days composting in the four experiments, but virus infectivity was detected only in one process after 30 days. Our results show that the use of composts using plant residues from PMMV and MNSV-infected crops as organic amendments in SE Spain do not appear to pose a risk of re-introducing pathogens to soil. Environmental conditions in that area are suitable for the adequate elimination of these pathogens from infected vegetable residues through composting even during winter.     

黄皮辣椒和青皮辣椒表型性状对比分析

中国是世界上最大的辣椒生产国和消费国,青皮辣椒和黄皮辣椒是市场上主要的蔬菜辣椒品种,为了解目前市场上主流黄皮辣椒和青皮辣椒品种在表型性状上的特点和区别及遗传多样性,对目前市场上较为主流的36份黄皮辣椒品种和38份青皮辣椒品种的25个田间表型性状进行变异系数、遗传多样性指数、相关性、主成分及聚类的对比分析.结果表明:黄皮...     

Cucumber vein yellowing virus isolate-specific expression of symptoms and viral RNA accumulation in susceptible and resistant cucumber cultivars

Since its outbreak in Spain during the fall of 2000, Cucumber vein yellowing virus (CVYV) has become into a limiting factor in cucurbit cultivation in this country, particularly in cucumber. The impact of the virus has been limited after the introduction of resistant cucumber cultivars and the implementation of cultural practices to control whitefly, the virus vector. In Spain, CVYV isolates are genetically similar and cucumber resistance breaking isolates have not been reported. A CVYV isolate from Jordan (Jor) was previously reported as being more virulent in cucumber cv. Beit Alfa than an isolate from Israel. To study the reactions of different cucumber cultivars to the virulent Jor isolate in comparison with a Spanish isolate of (Alm 1A), we have inoculated both isolates in 10 commercial cucumber cultivars with resistance to the virus. Also, we have used real-time RT-PCR to estimate virus accumulation of Jor and Alm 1A isolates in three of these cultivars, one described as susceptible and two as resistant to CVYV. The Spanish Alm 1A isolate caused mild or no symptoms in resistant cultivars whereas Jor isolate caused intense symptoms in all cultivars. Alm1 A genomic RNA accumulated similarly in the three cultivars, whereas the accumulation of Jor genomic RNA was lower in the resistant cultivars than in the susceptible cultivar. Also the Jor isolate and accumulated earlier and at a higher level than the Alm 1A isolate in the three cultivars.     

How many Orius laevigatus are needed for effective western flower thrips, Frankliniella occidentalis, management in sweet pepper?

Frankliniella occidentalis (Pergande) is a primary pest of greenhouse crops worldwide, in organic and integrated pest management control practices, Orius spp. are frequently released for thrips control. However, Orius spp. are relatively expensive to produce. More cost-efficient rearing systems and reduced release rate might reduce the expense. In these trials, we released Orius laevigatus (Fieber) at different rates with or without simultaneous release the predatory mite Amblyseius swirskii Athias-Henriot, another known thrips predator, which is less expensive to rear. There was no significant difference in the number of O. laevigatus recovered in which either 2 or 6 individuals were released per square meter, and there was no difference in thrips control among any of the release strategies using O. laevigatus, suggesting that a reduced release rate can maintain effective thrips control. There was no significant difference in the quality or quantity of the pepper yield between treatments in which either 2 or 6 Orius/m² or Orius plus A. swirskii were released.     

Effects of an insect–nematode–fungus pest complex on grain yield and composition of specialty low linolenic acid soybean

Linolenic acid is a precursor to components in plant defense responses to pests and pathogens. Soybean cultivars with altered seed linolenic acid contents have been developed for improved oil qualities, specifically reduced fatty acid content with increased stability. We examined how three common soybean pests, the soybean cyst nematode (SCN, Heterodera glycines), brown stem rot (BSR) caused by Cadophora gregata and the soybean aphid (SBA; Aphis glycines), affect yield and seed linolenic acid percentage of low linolenic acid cultivars. In a micro-plot field experiment, soybean cultivars with varying concentrations of linolenic acid in the seed (ultra-low or low) and resistance to SCN (susceptible or resistant) were grown at a central Iowa research farm. Plots were kept free of pests (control) or artificially infested with a single pest (SCN, BSR or SBA) or the combination of all three pests (multiple pest). The use of resistant cultivars (SCN and BSR) or an insecticide at an economic threshold (SBA) was analyzed to determine the efficacy of current management recommendations for low linolenic acid soybean production. Seed was collected at the end of the season to measure yield and grain composition. All three pests alone or in combination were capable of reducing yield, but only the three pests in combination were capable of affecting seed linolenic acid percentages, increasing linolenic acid percentages by 11.7% in SCN-susceptible cultivars. For all three pests, current management recommendations (resistant cultivars or economic thresholds) provided protection of both yield and grain composition, indicating no changes in management are necessary for altered linolenic acid soybean cultivars.     

Screening of three sweet potato (Ipomoea batatas L.) cultivars for resistance to different virulence groups of root-knot nematodes (Meloidogyne spp.) under controlled conditions

The susceptibility of three sweet potato cultivars (Ipomoea batatas L.) C4, TIS 3290 and TIS 9162 was evaluated against 156 isolates of Meloidogyne spp. with the aim to include resistant/tolerant sweet potato cultivars in a crop rotation scheme for the management of root-knot nematodes. The nematode isolates corresponded to races 1, 2 and 3 of Meloidogyne arenaria (n = 7), races 1, 2, 3 and 4 of M. incognita (n = 131) and Meloidogyne javanica (n = 18). Also, the isolates of M. incognita were differentiated in virulence groups: Pepper (n = 35), Pepper-Mi (n = 25), Tomato (n = 41) and Tomato-Mi (n = 30), depending on their ability to parasitize resistant pepper and tomato cultivars. The tested isolates of M. javanica parasitized C4 and TIS 3290, but not TIS 9162, whereas M. arenaria parasitized C4 and TIS 9162, but not TIS 3290, and M. incognita was able to parasitize the three sweet potato cultivars tested. C4 was the most susceptible cultivar to all nematode species tested, especially M. incognita, TIS 3290 was the most resistant and TIS 9162 was in between (7.2, 62.9 and 26.9% of resistant plants, respectively). Susceptibility of the sweet potato cultivars showed slight variations depending on the race or virulence group of M. incognita. The results suggest that sweet potato cultivars TIS 3290 and TIS 9162 may be used as rotation crops in fields where root-knot nematodes are present, their selection depending on the Meloidogyne isolates present. The use of resistant sweet potato cultivars would be preferably combined with other management practices to avoid virulence selection in nematode isolates.     

Field evaluation of yield effects on the U.S.A. heirloom sweetpotato cultivars infected by Sweet potato leaf curl virus

The incidence of Sweet potato leaf curl virus (SPLCV), a Begomovirus, on sweetpotato, Ipomoea batatas (L.) Lam. (Convolvulaceae), in South Carolina, U.S.A. has increased rapidly in recent years. This is likely due to the use of infected propagating materials and the increasing population of its vector, the sweetpotato whitefly, Bemisia tabaci (Gennadius). In this study, we demonstrated in field experiments that SPLCV infection reduced the yields of most heirloom sweetpotato lines relative to the yields of non-infected plants. Real-time polymerase chain reaction (PCR) technology specific to several common sweetpotato viruses was used to determine the virus infection status in 69 selected accessions of heirloom sweetpotato lines. Meristem tip culture technology was used to regenerate virus-free plants from these materials. To ensure the virus-free status, each mericlone was evaluated using real-time PCR and graft bio-indexing on the indicator species, Ipomoea setosa Ker Gawl. Mericlones of 27 cultivars were found to be free of the viruses. The 27 cultivars were included in a field test to determine the effect of SPLCV infection on yield. Yields of virus-free plants of the cultivars ranged from 10 to 80% greater than the yields of SPLCV-infected plants. However, the yield differences between virus-free and infected plants were diminished in the second year of the field experiment due to a rapid re-infection by SPLCV. These results demonstrate the importance of using certified, virus-tested seed roots or cuttings. The rapid re-infection of the virus-tested sweetpotato plants with SPLCV observed in these studies suggests that management of the whitefly population should be a critical element in control of this important virus.     

四川攀西地区芒果病虫害调查研究

2010～2013年对四川攀西地区芒果病虫害进行调查,结果为：病害46种,害虫共33种,分属8目20科,发现国内未见报道的芒果新害虫榕母管蓟马。分析阐述主要病虫害炭疽病、白粉病、畸形病(丛芽病)、细菌性黑斑病、幼果果肉生理性褐变黑果病、主干裂皮病、低温、蓟马、桔小实蝇、叶瘿蚊、介壳虫的危害情况;当前严重威胁攀西芒果产业发展的危险性病害为芒果畸形病(又称丛芽病)、芒果猝死病(又称速死病)和芒果果实象甲。编写“攀西地区芒果病虫害名录”,并提出防控策略。     

AVRDC的大豆种质资源研究

根据ＡＶＲＤＣ历年研究年报内容,本文简要介绍了其大豆种质资源研究进展,从１９７３年到１９９５年底,ＡＶＲＤＣ共收集大豆种质资源１３,６１８份,目前已全部保存在中期库和长期库中。１９８６年建立了一套完整的中心化种质引进系统,新引进种质主要信息供所有科学家利用。针对热带地区大豆种子储存难的问题。对大豆种质储藏条件,种子寿命,储藏期间的生化物质变化及保存技术进行了较多的研究。大豆育种家、病理学家、昆虫学     

Integrated management of Phytophthora capsici on bell pepper by combining grafting and compost treatment

In 2010 and 2011 an initial set of trials were carried out in order to evaluate the susceptibility of rootstocks used for grafting bell pepper (Capsicum annuum L.) in Italy to Phytophthora capsici, in comparison with widely used cultivars of pepper. In a second set of trials carried out in 2011 and 2012, grafting bell pepper onto resistant or partially resistant rootstock was combined with the use of compost-amended soil, to control Phytophthora blight. Trials were carried out in artificially or naturally infested soil, using five bell pepper cultivars (Fenice, Sienor, San Marco, Fiume, Cuneo) as susceptible not-grafted controls. In three trials, carried out in the presence of soil artificially infested with P. capsici, disease incidence in control plots ranged from 73 to 100% for the cvs. Cuneo and Fiume. Both cvs. Cuneo and Kaiman grafted on “Tecnico F1” rootstock provided complete control of P. capsici. A lower disease control, on the same cultivar, was provided by “Robusto” and “Capsifort”. On the cv. Fiume, “Terrano” provided complete control of the disease. By grafting all cultivars on “Robusto”, “Brutus”, “Snooker” and “Capsifort” a disease reduction by 68%–93%, 86%–100%, 67%–100% and 55%–78%, respectively, was provided. The general linear model analysis showed that for trials carried out under natural infestation the addition of compost to the soil, as well as the interaction of compost-amended soil with grafting, were significant factors influencing disease incidence reduction. The effect of grafting was a significant factor in reducing the percentage of diseased plants in all the trials. The addition of compost to the soil resulted in an effective and low-cost disease management solution, particularly when combined with susceptible not-grafted hybrids of bell pepper or when partially resistant rootstocks were used.     

湖南省主要抗病虫品种选育和利用现状与问题

全面分析了湖南省主要病虫灾害的现状、发生趋势,认为随着水稻种植结构和栽培技术的变革以及水稻新品种的应用,病虫害发生种类及其危害性的变化,将使病虫害问题更加突出。在对抗性品种在农业生产中的实际效用进行分析后,提出了抗病虫品种选育和利用中存在的问题及改进意见。     

Climate Change and Potato Production in Contrasting South African Agro-Ecosystems 3. Effects on Relative Development Rates of Selected Pathogens and Pests

A set of daily weather data simulations for 1961 to 2050 were used to calculate past and future trends in pest and disease pressure in potato cropping systems at three agro-ecologically distinct sites in South Africa: the Sandveld, the Eastern Free State and Limpopo. The diseases and pests modelled were late blight, early blight and brown spot, blackleg and soft rot, root-knot nematodes and the peach-potato aphid Myzus persicae (as indicator of Potato virus Y and Potato leaf roll virus). The effects of climate on trends in relative development rates of these pathogens and pests were modelled for each pathogen and pest using a set of quantitative parameters, which included specific temperature and moisture requirements for population growth, compiled from literature. Results showed that the cumulative relative development rate (cRDR) of soft rot and blackleg, root-knot nematodes and M. persicae will increase over the 90-year period in the areas under consideration. The cRDR of early blight and brown spot is likely to increase in the wet winter and wet summer crops of the Sandveld and Eastern Free State, respectively, but remains unchanged in the dry summer and dry winter crops of the Sandveld and Limpopo, respectively. Climate change will decrease the cRDR of late blight in all of the cropping systems modelled, except in the wet winter crop of the Sandveld. These results help to set priorities in research and breeding, specifically in relation to management strategies for diseases and pests.