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Pathogenesis-related (PR) genes are useful molecular markers, and gene expressions are activated in the reaction of plant-parasitic nematodes. Determining the PR gene expression and the resistance reaction of Phaseolus vulgaris L. genotypes against root-knot nematode are valuable for understanding plant–nematode interactions. However, resistance reactions of P. vulgaris genotypes and the gene expression of host–nematode interactions are not fully understood. Therefore, this study aimed to determine the expression of PR genes during the infection of Meloidogyne incognita on resistant and susceptible bean varieties at 1, 3, 5, and 7 days postinfection (dpi). The results revealed that one genotype gave a reaction as “immune”, and numerous genotypes were susceptible. The expression of PvPR1 and PvPR2 genes reached the highest peak at 1 dpi in nematode-infected immune plants, and the expression of PvPR1 reached 5 dpi in susceptible plants. In conclusion, PR genes involved in nematode resistance and parasitism and the immune common bean genotype have great potential in breeding programs and understanding the exact location of resistance on the gene map would be advantageous as future work.

Several pathogens, including nematodes, have severe effects on plant development and growth, and immense populations of parasitic nematodes may cause plant death and crop loss. Obligate plant-parasitic nematodes and root-knot nematodes belonging to the genus Meloidogyne are significant parasites in crops. During nematode infection, damage-associated molecular patterns play a role in the activation of plant defence responses to pathogens. Several genes are involved in Meloidogyne parasitism. However, the expression of nematode-responsive genes CRF1, WRKY45, and PR7 during infection with different parasitic nematode species is not well understood. Therefore, this study aimed to reveal plant responses to differential gene expression of nematode-responsive genes in tomato plants, and their relationship to nematode reproduction and comparative phylogeny. Molecular methods for gene expression, greenhouse work for nematode reproduction, and phylogenetic analysis were used to determine nematode–plant interactions. The results revealed that differential gene expression of CRF1, WRKY45, and PR7 depended on the nematode species. The relative CRF1 gene expression reached its highest level at 3 dpi, following nematode infection. In conclusion, plant defense responses disturbed the expression of nematode-responsive genes, and the differential expression of nematode-responsive genes was affected by nematode species and nematode parasitism.

Strawberry is an important crop for many features, including being rich in vitamins and minerals. In addition to fresh consumption, it has been appealing to a wide range of consumers in recent years. Its cultivation is in flat areas, slopes, and areas where other crops are limited. Many pests and diseases that are the main biotic stress factors cause significant crop losses in strawberry cultivation. The aim of this chapter is to reveal biotic stress factors and their management. Several plant-parasitic nematodes, fungal diseases, weeds, pests, virus diseases, and bacterial diseases are the main biotic stress factors in plant growing and fruit ripening. The preparation of this book chapter is based on previously published sources and researches and manuscripts. In this section, it is aimed to provide readers with new perspectives in terms of collecting data on nematodes, diseases, pests, weeds, and fruit ripening of strawberry plants. The effect and mechanism of those biotic stress factors on strawberry growing are discussed and revealed in this chapter.

Several pathogens and pests damage tomato plants, and only one and/or more pathogens and pests can coexist in the same plant at the same time. As several numerous pathogens are found in the same plant, the damage to the tomato plants is higher. Pathogens such as nematodes, viruses, viroids, bacteria, and insects adversely affect the growth and development of tomato plants. They may infect roots or upper part of the plant and can cause not only slow down the growth of plants, but also crop losses and their death. Damaging of plant caused by pathogens and pests reduces the market value of plant products. Those pathogens and pests are also called biotic stress agents. The damage, mode of infection, and the mechanism of infection in each tomato plant and pathogens might be different. This situation is crucially important to understand plant pathogen relationship in detail in terms of controlling pests and pathogen. The effect of each pest/pathogen on tomato plants during the cultivation, the type of damage, and new developments and perspectives on morphological and molecular aspects in tomato-pathogen interactions will be discussed in this chapter.

Salicylic acid (SA) stimulates the mechanism of the plant defence and involves in a role in plant pathogen interactions. Plant parasitic nematodes are important biotic stresses causing negative effect on plant growth and development. Treatment of plant roots with SA may increase the plant defence mechanisms against biotic stresses. However, the treated effect of SA on plant defence mechanisms against a root-knot nematode, Meloidogyne incognita, has not been fully understood in terms of plant pathogen interactions. Therefore, this study was aimed to determine the most effective SA exposure time on increasing the plant defence and decreasing the nematode parasitism in Solanum lycopersicum. In addition, effects of SA treatment on the expression Pathogenesis Related Gene 5 (PR5) was evaluated. For this aim, tomato seedlings were exposed within 1000µM SA concentration with distinctive time durations. The expression of PR5 gene was accomplished using RT-PCR at 1, 3, 7, 14, 21 days post infection (dpi) for each sample. Root galling index, nematode number and reproduction rate were evaluated. Results revealed that nematode reproduction rate was decreased at in longer durations after SA treatment on roots. The highest nematode reproduction rate was determined in nematode+water (non-SA treatment) application compare to SA treatments. The highest increased level of expression of SlPR5 gene was determined in early (1 dpi) SA treatment + nematode infection. To conclude, SA treatment may increase the plant defence mechanisms and PR5 gene may involve in nematode-plant parasitism.

Salicylic acid (SA) induces the mechanism of the plant defence and plays a role in plant -pathogen interactions. Following the nematode infection, effects of SA treatment on plant weights and the expression of pathogen related gene have not been fully understood. The present study was aimed to determine the effects of SA treatment on the expression Pathogenesis related 1 gene (PR1 gene) and alteration on plant parameters in tomatoes (Solanum lycopersicum). Plant seedlings were dripped within the SA solution. The expression of PR1 gene achieved using RT-PCR at 1, 3, 7, 14, 21-days post infection (dpi) with Meloidogyne incognita. Upregulation of PR1 gene was determined in early (1 dpi) and late (21 dpi). SA treatment and nematode infection altered plant parameters. SA treatment increased the plant defence mechanisms in tomato against Meloidogyne incognita.

Plant hormones, such as auxin, play crucial roles in many plant developmental processes, which is crosstalk with gibberellin and strigolactone. The roles of hormones may vary in the biosynthesis of metabolisms. During the pathogen attack, including plant-parasitic nematodes, viroid, phytoplasma, virus, and bacteria, plant hormones are involved in several plant processes. Ethylene (ET), salicylate (SA), jasmonate (JA), and abscisic acid (ABA) primarily regulate synergistically or antagonistically against pathogens. Those pathogens—nematodes, bacteria, viroid, phytoplasma, and viruses regulate several plant hormones for successful parasitism, influencing the phytohormone structure and modifying plant development. Several genes are related to plant hormones that are involved in pathogens parasitism. In this chapter, how pathogens affect plant hormones in plants growing are discussed.

AimsCitrus plants are hosts of numerous plant-parasitic nematodes (PPNs), which are microscopic organisms and hidden enemies for plants. Among the PPNs, the citrus root nematode, Tylenchulus semipenetrans, causes significant damage to citrus plantations in the world. Understanding the citrus nematode population, precise nematode identification, host preference among the citrus species, and damage threshold level are crucially important to control T. semipenetrans. Although some studies have been conducted, minutiae about citrus plant-nematode interactions, nematodes density, and molecular nematode identification have not been well understood. MethodsThis study aimed to reveal nematode identification using molecular and morphological methods, host-nematode interactions, host (citrus species) preference, damage of economic threshold (ET), and economic-injury level (EIL). Therefore, citrus plantations of different provinces located in the Mediterranean region of Turkey were investigated.ResultsITS sequences revealed that samples were infested with the citrus root nematode Tylenchulus semipenetrans. The lowest nematode density was obtained from Mersin (80-second-stage juveniles(J2s)/150g-soil), while the highest density was obtained from Adana (18260-J2s/150g-soil). Out of the 73 samples collected from the Mediterranean region, 21.9% have passed the EIL, while 8.2% are on the ET. Citrus nematode reproduced utmost level on roots of Citrus reticulata, followed by C.sinensis, C.limon, and C.parasidisi, respectively. ConclusionThis study revealed that the Citrus nematode is more common than it was thought and that the population fluctuations change according to the citrus plant species. It is of great importance to investigate the possible genetic changes in nematode populations caused by global warming and its negative impact on citrus yield.

Potato, Solanum tuberosum, the most important non-grain food crop and essential crop globally, has been widely cultivated around the world for centuries. The significance of this plant is increasing due to high nutritional value of the tubers combined with the simplicity of its propagation. As a plant organ, tuber of potato, is mainly edible part of it and popular as nutrient for almost all nations. Tuberization in potato is a very complex biological occurrence affected by numerous ecological signals, genetics, plant nutrition and several different hormones. Many pests including nematodes limit potato tuber development that plant hormones play roles in nematode feeding cell formation. Parasitic nematodes, important pests which cause damage to plants, tubers, suck up nutrients from plants and weaken plant development and yield losses. Many genes involve in tuber development and plant response nematodes. The aim of this chapter is to demonstrate the new advances in the field of molecular host-nematode interactions and tuber development.

Potato (Solanum tuberosum L.) cyst nematodes (Globodera rostochiensis (Wollenweber) and Globodera pallida (Stone) cause significant yield losses and have been listed as quarantine pests for many countries in the world including Turkey, and the European and Mediterranean Plant Protection Organization (EPPO, A2). In Turkey, the current potato production area is decreasing due to contamination by quarantine agents, and new fields are under threat of invasion by new quarantine organisms. In this study, samples were collected from Nevşehir province, Turkey, in potato growing fields during the spring growing season in 2014-2015. Soil samples were washed using Fenwick’s can and cysts were extracted and identified using molecular markers. The species-specific molecular markers generated a 435 bp using PITSr3, PITSp4 and ITS5 primers. The potato golden cyst nematode, G. rostochiensis was identified in Nevşehir potato production areas and this is the first report for the Central Anatolia Region. In addition, G. rostochiensis was found in two samples of the same field in the surveys. The average cyst nematode density was determined as 60 cysts in 250 g soil. Patates (Solanum tuberosum L.) kist nematodları (Globodera rostochiensis (Wollenweber) ve Globodera pallida (Stone) önemli verim kayıplarına neden olmakta, Türkiye de dahil olmak üzere dünyadaki birçok ülke, Avrupa ve Akdeniz Bitki Koruma Örgütü’nde (EPPO, A2) karantina zararlıları olarak listelenmiştir. Türkiye'de mevcut patates üretim alanı karantina zararlısı olarak bulaşmaya bağlı olarak azalmakta ve yeni alanlar yeni karantina organizmaları tarafından istila tehdidi altında bulunmaktadır. Bu çalışmada, Türkiye, Nevşehir ilinden 2014-2015 yıllarında bahar mevsiminde patates yetiştirme alanlarında örnekler toplanmıştır. Toprak örnekleri Fenwick aletinde yıkanarak bulaşık örneklerdeki kistler elde edilmiş ve kist popülasyonlarının moleküler olarak teşhisleri yapılmıştır. Kist popülasyonlarının moleküler düzeyde türe özgü PITSr3, PITSp4 ve ITS5 primerleri kullanılarak yapılan teşhiste söz konusu primerlerin 435 bp de bant oluşturduğu tespit edilmiştir. Bu çalışma sonucunda Nevşehir ili patates ekiliş alanlarında patates kist nematodu G. rostochiensis saptanmış olup, bu sonuç İç Anadolu Bölgesi için ilk kayıt olma özelliğini taşımaktadır. Ayrıca, sürveylerde aynı tarlaya ait iki örnekte G. rostochiensis’e rastlanılmış, 250 g toprakta ortalama 60 kist yoğunluğunda olduğu tespit edilmiştir.

Root knot nematodes areeconomically important crop pests that is difficult to control. Soil fumigationand solarization are significant methods to control root knot nematodes. Theapplication of soil fumigation and solarization on nematodes is not fully understood.Therefore, this study was carried out to determine the effect of thecombination of the solarization with reduced dose of metam-sodium to controlroot knot nematodes in pepper. Experiments were conducted in greenhouses inAdanalıoğlu and Kazanlı region of Mersin province in 2014-2015. Following theplanting beds were prepared in the experiments, the solarization with reducedmetam-sodium fumigant was applied at 750 l/ha. The plots were saturated viadrip irrigation, and waited for two days before metam-sodium was applied with100 ton/ha water. The solarization application in July 2014 combined withreduced metam-sodium treatment were effectively protected pepper againstroot-knot nematodes until July 2015 where gall formation ranged between 0-1.4.Solarization combination with reduced metam-sodium application resulted withgall formation below 2 while in non-treated parcels were ranged from 6.4 to7.1. Solarization with reduced metam-sodium application resulted 98,8% to234,5% yield increase in pepper. Results indicate that combination ofsolarization with reduced metam-sodium application reduced the root-knotnematodes. It is thought that when the manufacturers apply the solarizationwith combination of metam-sodium correctly, they will not have nematodeproblems and the possibility of encountering lower ineffectiveness of the chemicals., Kök ur nematodları kontroledilmesi zor önemli ürün zararlılarındandırlar. Toprak fümigasyon vesolarizasyon kök ur nematodlarını kontrol etmek için önemli birer yöntemlerdir.Nematod kontrolünde toprak fümigasyonunun ve solarizasyonun uygulanması tamolarak anlaşılamamıştır. Bu nedenle, bu çalışma, biberde, düşük dozdametam-sodyum fumigant ile solarizasyon uygulamasının kombinasyonunun kök urnematodlarına etkisini belirlemek için yapılmıştır. Denemeler2014-2015 yıllarında Mersin ili Adanalıoğlu ve Kazanlı'da mevcut seralardayürütülmüştür. Deneme dikim sırtları hazırlanmasından sonra, metam-sodyumfümigantının azaltılmış dozu 750 l / ha'da uygulanmıştır. Parseller damlasulama ile doyurulduktan iki gün sonra metam-sodyum 100 ton/ha su ileverilmiştir. Temmuz 2014’teki solarizasyon ve metam-sodyum kombinasyonuygulamasının Temmuz 2015'e kadar biber köklerinde mevcut ur oranını 0-1.4arasına düşürdüğü ve bu uygulamanın kök ur nematodlarını azaltmada etkiliolduğu saptanmıştır. Azaltılmış metam-sodyum uygulamasıyla kombine edilensolarizasyon uygulamalarında gal indeksi 2'nin altında olurken, kontrolparsellerinde 6.4 ile 7.1 arasında bulunmuştur. Azaltılmış metam-sodyum ilesolarizasyon uygulamasının % 98,8-234,5 oranında verim artışı sağladığıgörülmüştür. Sonuç olarak azaltılmış metam-sodyum uygulaması ile solarizasyonkombinasyonunun kök ur nematodlarına etkili olduğu saptanmıştır. Üreticilerinmetamsodium ile solarizasyon uygulamasını doğru uygulama yaptıklarında nematodsorunu yaşamayacakları ve ilaçların etkisizliği ile karşılaşma olasılığının azolabileceği düşünülmektedir.

The present study was carried out in the agricultural areas of Northwestern Turkey with the purpose to assess the occurrence ofPasteuriaspp. bacteria on plant-parasitic nematodes. The soil samples were collected from olive, cherry, peach, pear, almond, walnut, apple orchards, vineyards, vegetable, and sunflower fields, analyzed and the bacterium was detected on 30 nematode species belonging to 31 families. Nematode individuals fromRotylenchus, Helicotylenchus, Pratylenchus, Tylenchorrhynchus, andGeocenamusspp. were most frequently infected while the average height and width of the spore core and endospore ranged between 3.70-4.90 and 1.40-2.37 μm, respectively. The results indicated thatHelicotylenchus digonicus,Pratylenchus thornei,P. neglectus,Geocenamus brevidens, Tylenchhorhynchus cylindricus,Rotylenchus cypriensis,Meloidogyne javanica, andM.incognitaindividuals were the most parasitized by the bacterium.

Root knot nematodes (Meloidogyne spp.) cause immense yield losses in crops throughout the world. Use of resistant germplasms of plants limits the root knot nematode damages. In this study, 87 common bean (Phaseoulus vulgaris L.) genotypes were screened against the root knot nematode, Meloidogyne incognita to determine the resistance response under growth chamber conditions in Turkey. P. vulgaris genotypes were evaluated based on resistance index (RI); root galling severity and nematode egg mass production on a 1-9 scale. The nematode negatively influenced the growth (fresh weight) of bean genotypes. At the completion of the study, 13 bean genotypes were found as immune (Sehirali), highly resistant (TR42164, Seleksiyon 5, Seker Fasulye, Fas-Agadir-Suk-1) and moderately resistant (Acik Badem, TR68587, TR43477, TR53827, TR28018, Gülnar-3, Siyah Fasulye, Kibris Amerikan) against M. incognita thus suggesting the use of such genotypes in breeding studies as a parental material to develop the root knot nematode resistant cultivars.

Determining the Optimal Meloidogyne Incognita Inoculum Level, Inoculation Time, Pathogencity and Gall Development on Tomato Roots for Resistance Experiments in Breeding Programs. Root knot nematodes (RKN) cause a significant damage to many cultivated crops and present study was conducted to determine the most appropriate inoculum levels of a ubiquitous RKN nematode in warm climate, Meloidogynev incognita, inoculation time and plant age for the screening of nematode resistance studies on plant breeding programs under controlled conditions. The inoculum level experiment was conducted to investigate the effect of four M. incognita inoculum levels (1000, 1500, 2000, 2500 juveniles/ 1000 gram soil mix) on three different age of susceptible tomato plants. Gall development was observed at 3 different ages susceptible tomato plants with 7 different time points. The highest gall numbers were observed on nematode infected 3 day old plant roots and the least number of galls were detected on the roots of 5 day old plants. First galls were observed at 1 dpi and the highest gall number was observed on the 21st gall counting day on three day old tomato roots. Thus the inoculation of 2000- 2500 second stage juveniles /1000 gram soil mix to 3 days old tomato plants was the best to reach high gall numbers which are suitable for screening of nematode resistance studies on plant breeding programs5