scholarly journals Tomato hybrids with complex resistance for ground greenhouses

2021 ◽  
pp. 34-37
Author(s):  
Т.А. Терешонкова ◽  
Р.А. Багров ◽  
М.Г. Фомичева ◽  
Н.Ф. Тенькова ◽  
Е.В. Титова ◽  
...  

На фоне усиливающейся инфекционной нагрузки на культуру томата, обусловленной появлением новых болезней и новых физиологических рас традиционных патогенов, возрастает значение создания и использования в производстве гетерозисных гибридов с комплексной устойчивостью. Возрастает вредоносность новых насекомых-вредителей культуры томата. По вредоносности выходят на первое место томатная минирующая моль (Tuta absoluta) и западный цветочный трипс (Frankliniella occidentalis), который помимо нанесения прямого ущерба культуре выступает как переносчик вирусных заболеваний, в том числе вируса бронзовости (TSVW). Начатая селекционная программа на полевую устойчивость томата к трипсу позволила в 2020–2021 годах выделить восемь источников устойчивости среди образцов различных товарных групп. В результате двадцатилетней селекции созданы коммерческие гибриды с различным набором генов устойчивости. В задачи современной селекции входят этапы оценки и отбора селекционного материала на наличие генов устойчивости в генотипах методами ПЦР-диагностики, а также контроль устойчивости путем испытания материала в условиях инфекционных фонов или искусственного заражения. Важный этап – контроль товарных партий семян на присутствие генов устойчивости. Результаты ПЦР-анализа коммерческих гибридов на четыре гена устойчивости в сочетании с испытанием полевой устойчивости к кладоспориозу на сильном многолетнем инфекционном фоне приведены в табличной форме. Результаты показывают, что практически во всех товарных группах есть гибриды с устойчивостью к кладоспориозу, фузариозному увяданию, вирусу томатной мозаики (ВТоМ) и галловой нематоде. Также была обнаружена относительная устойчивость к фитофторозу у гибрида F1Изящный (Ph2\Ph2). Сегодня проводится работа по расширению числа генов для ПЦР-анализа селекционного материала. Under conditions of the increasing infectious load on the tomato crop due to the emergence of new diseases and new physiological races of traditional pathogens, the importance of creating and growing heterotic hybrids with complex resistance is increasing. The harmfulness of new insect pests of tomato culture is also increasing. In terms of harmfulness, the tomato mining moth (Tuta absoluta) and the western flower thrips (Frankliniella occidentalis) take the first place, which, in addition to causing direct damage to the culture, is a carrier of viral diseases, including Tomato spotted wilt virus. The started breeding program for the field resistance of tomato to thrips made it possible for the period 2020–2021 to identify 8 sources of resistance among the samples of various commodity groups. As a result of 20 years of selection, commercial hybrids with different sets of resistance genes have been created. The goals of modern breeding include breeding material assessment and selection for the presence of resistance genes in genotypes by PCR diagnostics method, as well as control of resistance by testing the material under infectious backgrounds or artificial infection inoculation. Another important step is the control of commercial seed lots for the presence of resistance genes. The results of PCR analysis of commercial hybrids for 4 resistance genes in combination with the test of field resistance to Cladosporium fulvum under condition of strong long-term infectious background are given in tabular form. These results show that in almost all product groups there are hybrids with resistance to ToMV, in combination with other resistances, including the relative resistance to late blight in the F1 Iziyaschniy (Ph2\Ph2) hybrid. Currently, the progress is being made towards expanding the number of genes for PCR analysis of breeding material.

2020 ◽  
Vol 55 (3) ◽  
pp. 350-365
Author(s):  
Yinping Li ◽  
Raymond A. Cloyd ◽  
Nora M. Bello

Abstract The rove beetle, Dalotia coriaria (Kraatz) (Coleoptera: Staphylinidae), is a soil-dwelling predator that preys upon insect pests residing in growing media. Minimal information exists addressing its predation on western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), below-ground life stages. Two laboratory experiments were conducted to assess the effects of western flower thrips pupal stage, predator–prey ratio, and searchable area on predation efficacy of rove beetle adults. In Experiment 1, predation was recorded in response to two thrips pupal stages (prepupae and pupae); three predator–prey ratios (1:5, 1:10, 1:15) and predator–prey ratios that were 2, 3, and 4 times greater. Experiment 2 was designed to assess predation in response to those predator–prey ratios along with searchable areas in 15.2- and 11.5-cm-diameter containers. Response was measured by capturing thrips adults on yellow sticky cards (YSC) as they emerged from pupation. The estimated mean probability of thrips adults captured on the cards was significantly higher for the 1:5 (61.1%) than for the 1:10 (39%) and 1:15 (34.7%) predator–prey ratios. The estimated mean probability of thrips adults captured on the cards for 2 times the predator–prey ratio (57%) was significantly higher than 3 times (37.2%) and 4 times (40.6%) the ratios. A significantly higher estimated mean probability of thrips adults was captured on the cards in the 15.2-cm-diameter containers than in the 11.5-cm-diameter containers. We conclude that a predator–prey ratio of 1:15 would result in fewer rove beetle adults needed to reduce western flower thrips prepupae/pupae stages and subsequent adult populations.


HortScience ◽  
2020 ◽  
Vol 55 (8) ◽  
pp. 1323-1326
Author(s):  
Nathan J. Herrick ◽  
Raymond A. Cloyd

Western flower thrips, Frankliniella occidentalis, and fungus gnats (Bradysia spp.) are major insect pests of greenhouse production systems. Both insect pests have life stages that reside in the soil or plant-growing medium: prepupae and pupae of western flower thrips and fungus gnat larvae. There are unsubstantiated allegations made by a manufacturer that certain plant-growing media that contain a bacterium, Bacillus pumilus, and arbuscular mycorrhizal fungus, Glomus intraradices, negatively affect the survival of western flower thrips pupae and fungus gnat larvae. Therefore, we conducted a study involving laboratory experiments replicated over time (2019 and 2020) to investigate the influence of the plant-growing media Pro-Mix BX + Mycorrhizae and Pro-Mix BX + Biofungicide + Mycorrhizae on western flower thrips pupae and fungus gnat larvae. All experiments involved placing western flower thrips pupae or fungus gnat larvae (second and third instar) into 473-mL deli containers with the different treatments (plant-growing media). A 5 × 4-cm section of a yellow sticky card was affixed to the lid of each deli container. After 21 days, the number of western flower thrips or fungus gnat adults that emerged from the growing media and were captured on the yellow sticky cards was recorded. The use of the yellow sticky card was an indirect assessment of western flower thrips pupal or fungus gnat larval mortality. We found none of the plant-growing media tested that contained a bacterium and/or arbuscular mycorrhizal fungus affected the survival of western flower thrips pupae or fungus gnat larvae. Therefore, greenhouse producers should be leery of information provided by manufacturers that does not contain valid, scientifically based data.


2005 ◽  
Vol 95 (6) ◽  
pp. 664-671 ◽  
Author(s):  
L. Chartrain ◽  
S. T. Berry ◽  
J. K. M. Brown

The International Maize and Wheat Improvement Center (CIMMYT), Mexico, germplasm-derived wheat (Triticum aestivum) Kavkaz-K4500 L.6.A.4 (KK) is one of the major sources of resistance to Septoria tritici blotch (STB). KK is resistant to STB in field conditions in the UK even though a large majority of Mycosphaerella graminicola isolates are virulent to it. The genetics of the resistance of KK to four isolates of M. graminicola were investigated. KK has at least five isolate-specific resistance genes including Stb6 on chromosome 3A plus a second gene for resistance to isolate IPO323, two genes on chromosome 4A, both in the region where Stb7 is located with one designated as Stb12, and a gene designated Stb10 on chromosome 1D. Taken together, the widespread use of KK as a source of resistance to STB, its high resistance in field conditions, and its high susceptibility to M. graminicola isolates, which are virulent to all its resistance genes, suggest that high levels of field resistance to STB might be achieved by pyramiding several isolate-specific resistance genes.


2006 ◽  
Vol 16 (4) ◽  
pp. 633-636 ◽  
Author(s):  
Brian K. Hogendorp ◽  
Raymond A. Cloyd

Sanitation, which includes removing plant and growing medium debris, is an important component of any greenhouse or nursery pest management program. However, there is minimal quantitative information on how sanitation practices can reduce pest problems. In this study, conducted from May through Nov. 2005, we evaluated plant and growing medium debris as a source of insect pests from four greenhouses located in central Illinois. Two 32-gal refuse containers were placed in each greenhouse with a 3 × 5-inch yellow sticky card attached to the underside of each refuse container lid. Each week, yellow sticky cards and plastic refuse bags were collected from the containers and insects captured on the yellow sticky cards were identified. Insects captured on the yellow sticky cards were consistent across the four greenhouses with western flower thrips (Frankliniella occidentalis), fungus gnats (Bradysia spp.), and whiteflies (Bemisia spp.) the primary insects present each week. Insect numbers, in order of prevalence on the yellow sticky cards, varied across the four locations, which may be related to the type of plant debris discarded. For example, extremely high numbers of adult whiteflies (range = 702 to 1930) were captured on yellow sticky cards in one greenhouse each month from August through November. This was due to the presence of yellow sage (Lantana camera), bee balm (Monarda didyma), garden verbena (Verbena × hybrida), common zinnia (Zinnia elegans), sage (Salvia spp.) and fuchsia (Fuschia spp.) debris that was heavily-infested with the egg, nymph, pupa, and adult stages of whiteflies. High western flower thrips adult numbers in the greenhouses were generally associated with plant types such as marguerite daisy (Dendranthema frutescens) and pot marigold (Calendula officinalis) disposed while in bloom with opened yellow flowers, which contained adult western flower thrips. Based on the results of this study, it is important that greenhouse producers timely remove plant and growing medium debris from greenhouses or place debris into refuse containers with tight-sealing lids to prevent insect pests from escaping.


Plant Disease ◽  
2011 ◽  
Vol 95 (6) ◽  
pp. 762-766 ◽  
Author(s):  
M. N. Rouse ◽  
R. Wanyera ◽  
P. Njau ◽  
Y. Jin

Wheat stem rust (Puccinia graminis f. sp. tritici) race TTKSK (Ug99), with virulence to the majority of the world's wheat (Triticum aestivum) cultivars, has spread from Uganda throughout eastern Africa, Yemen, and Iran. The identification and spread of variants of race TTKSK with virulence to additional stem rust resistance genes has reminded breeders and pathologists of the danger of deploying major resistance genes alone. In order to protect wheat from this rapidly spreading and adapting pathogen, multiple resistance genes are needed, preferably from improved germplasm. Preliminary screening of over 700 spring wheat breeding lines and cultivars developed at least 20 years ago identified 88 accessions with field resistance to Ug99. We included these resistant accessions in the stem rust screening nursery in Njoro, Kenya for two additional seasons. The accessions were also screened with a bulk of North American isolates of P. graminis f. sp. tritici in the field in St. Paul, MN. In order to further characterize the resistance in these accessions, we obtained seedling phenotypes for 10 races of P. graminis f. sp. tritici, including two races from the race TTKSK complex. This phenotyping led to the identification of accessions with either adult-plant or all-stage resistance to race TTKSK, and often North American races of P. graminis f. sp. tritici as well. These Ug99 resistant accessions can be obtained by breeders and introgressed into current breeding germplasm.


HortScience ◽  
2019 ◽  
Vol 54 (5) ◽  
pp. 890-895 ◽  
Author(s):  
Yinping Li ◽  
Raymond A. Cloyd ◽  
Nora M. Bello

Western flower thrips, Frankliniella occidentalis, is one of the most destructive insect pests of greenhouse-grown horticultural crops. The primary method of managing western flower thrips populations involves applications of insecticides; however, there is no information associated with the effect of the insect growth regulator, pyriproxyfen, or the entomopathogenic fungus, Isaria fumosorosea, on western flower thrips pupae in growing media. Therefore, four laboratory experiments were conducted to determine the effect of pyriproxyfen and I. fumosorosea applied as a drench to growing media on western flower thrips pupae. Expt. 1 evaluated the efficacy of pyriproxyfen and I. fumosorosea on western flower thrips pupae. Based on the results from Expt. 1, Expt. 2 assessed the effect of pyriproxyfen in two growing media (LC1 and BM1) on western flower thrips pupae. Expts. 3 and 4 determined the residual activity of pyriproxyfen in growing media on western flower thrips pupae 3, 5, 7, and 14 days after treatments were applied. The pyriproxyfen treatment resulted in a significantly lower estimated mean probability of western flower thrips adults captured on yellow sticky cards (17%) compared with the water control (59%), untreated check (88%), and two I. fumosorosea treatments (46% for 1.0 g and 41% for 2.0 g of Ancora) in Expt. 1. However, for the two growing media in Expt. 2, the estimated mean probability of western flower thrips adults captured on yellow sticky cards was not significantly different between the pyriproxyfen treatment (LC1 = 15%; BM1 = 12%) and the water control (LC1 = 41%; BM1 = 24%). For either the pyriproxyfen treatment or the untreated check, there was no evidence of a significant difference between the two growing media on the estimated mean probability of western flower thrips adults captured on yellow sticky cards. Furthermore, there was no evidence of any residual activity 3 days after drench applications of pyriproxyfen. The results of the study have demonstrated that drench applications of pyriproxyfen are not affecting survival of western flower thrips pupae.


2009 ◽  
Vol 19 (3) ◽  
pp. 638-646 ◽  
Author(s):  
Raymond A. Cloyd

Pesticide mixtures are commonly used by greenhouse producers to deal with the array of arthropod (insect and mite) pests encountered in greenhouses. Greenhouse producers tank mix pesticides due to convenience because it is less time consuming, costly, and labor intensive to mix together two or more pesticides into a single spray solution and then perform one spray application compared with making multiple applications. Pesticide mixtures may also result in improved arthropod pest control. However, there has been no quantitative assessment to determine what pesticide mixtures (two-, three-, and four-way combinations) are being adopted by greenhouse producers and why. As such, a survey was conducted by distributing evaluation forms in conjunction with three sessions at two greenhouse producer conferences (two in 2007 and one in 2008) to obtain data on the types of pesticide mixtures used by greenhouse producers and determine if there are any problems associated with these pesticide mixtures. The evaluation form requested that participants provide information on the four most common pesticide mixtures (insecticides and/or miticides) used and for what specific arthropod pests. The response rate of the evaluation forms was 22.5% (45/200). The two-way pesticide mixture that was cited most often (n = 8) was the abamectin (Avid) and bifenthrin (Talstar) combination. The two pesticides typically included in a majority of the two-way and three-way mixtures were spinosad (Conserve) and abamectin. Spinosad was a component of 17 two-way and 7 three-way combinations, while abamectin was cited in 15 two-way and 9 three-way combinations. Both products are labeled for control of the western flower thrips (Frankliniella occidentalis), which is one of the most important insect pests in greenhouses. One pesticide mixture that was difficult to interpret involved the fungicides, thiophanate-methyl (Cleary's 3336) and metalaxyl (Subdue). This mixture was cited twice, and the arthropod pest listed was thrips (Thysanoptera). However, both fungicides have no insecticidal activity. Two of the mixtures listed in the survey used pesticides with similar modes of action: acephate (Orthene) + methiocarb (Mesurol), and pyrethrins (Pyreth-It) + bifenthrin (Talstar). A number of the pesticide mixtures listed for spider mites (Tetranychidae) were questionable due to similar life stage activity of the a.i. as indicated on the label including fenpyroximate (Akari) + clofentezine (Ovation), abamectin + chlorfenapyr (Pylon), and bifenazate (Floramite) + etoxazole (TetraSan). In fact, 38% of pesticide mixtures cited for twospotted spider mite (Tetranychus urticae) control should have been avoided due to analogous life stage activity. The data obtained from the survey clearly demonstrates that greenhouse producers implement a wide-range of pesticide mixtures to deal with the multitude of arthropod pests in greenhouses. However, the basis by which greenhouse producers decide the types of pesticides to mix together is not known. As such, the survey data can be used to direct future multistate or multiregional extension (outreach) efforts in developing programs specifically designed to educate greenhouse producers on which pesticides should and should not be mixed together.


PLoS Genetics ◽  
2021 ◽  
Vol 17 (7) ◽  
pp. e1009680
Author(s):  
Yayun Zuo ◽  
Yu Shi ◽  
Feng Zhang ◽  
Fang Guan ◽  
Jianpeng Zhang ◽  
...  

The evo of insecticide resistance represents a global constraint to agricultural production. Because of the extreme genetic diversity found in insects and the large numbers of genes involved in insecticide detoxification, better tools are needed to quickly identify and validate the involvement of putative resistance genes for improved monitoring, management, and countering of field-evolved insecticide resistance. The avermectins, emamectin benzoate (EB) and abamectin are relatively new pesticides with reduced environmental risk that target a wide number of insect pests, including the beet armyworm, Spodoptera exigua, an important global pest of many crops. Unfortunately, field resistance to avermectins recently evolved in the beet armyworm, threatening the sustainable use of this class of insecticides. Here, we report a high-quality chromosome-level assembly of the beet armyworm genome and use bulked segregant analysis (BSA) to identify the locus of avermectin resistance, which mapped on 15–16 Mbp of chromosome 17. Knockout of the CYP9A186 gene that maps within this region by CRISPR/Cas9 gene editing fully restored EB susceptibility, implicating this gene in avermectin resistance. Heterologous expression and in vitro functional assays further confirm that a natural substitution (F116V) found in the substrate recognition site 1 (SRS1) of the CYP9A186 protein results in enhanced metabolism of EB and abamectin. Hence, the combined approach of coupling gene editing with BSA allows for the rapid identification of metabolic resistance genes responsible for insecticide resistance, which is critical for effective monitoring and adaptive management of insecticide resistance.


2016 ◽  
Vol 15 (12) ◽  
pp. 2803-2808 ◽  
Author(s):  
Dong-gang LI ◽  
Xiao-yong SHANG ◽  
Stuart Reitz ◽  
Ralf Nauen ◽  
Zhong-ren LEI ◽  
...  

2017 ◽  
Vol 10 (1) ◽  
pp. 21-28 ◽  
Author(s):  
Surendra K. Dara

Aims:Lettuce and broccoli are high value vegetable crops in California. The western flower thrips,Frankliniella occidentalison lettuce, and the cabbage aphid,Brevicoryne brassicaeand the green peach aphid,Myzus persicaeon broccoli are important insect pests that are frequently managed with chemical insecticides.Observation:Efficacy of various chemical insecticides and the entomopathogenic fungusBeauveria bassianawas evaluated against these pests in field studies in the Santa Maria area of California. Some insecticides varied in their efficacy againstF. occidentalisfrom year to year and against different aphid species.Conclusion:A new insecticide sulfoxaflor provided good control of aphids on broccoli.Beauveria bassianademonstrated a potential for broccoli and lettuce integrated pest management.


Sign in / Sign up

Export Citation Format

Share Document