Browsing by Author "Risvanli, Mehmet Ramazan"

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Can Symbiotic Fungi Protect Plants From Insect Pests? a Simple Mathematical Model
(Wiley, 2021) Atlihan, Remzi; Britton, Nicholas F.; Demir, Semra; Papasidero, Annalisa; Risvanli, Mehmet Ramazan; Seminara, Manuela; Venturino, Ezio
A mathematical model is proposed for simulating and understanding the relationship between the potato plant and its most significant pest, the Colorado potato beetle, when mediated by mycorrhiza, a symbiotic plant-fungus association. From its analysis it is seen that, quite counterintuitively, an overabundant use of mycorrhiza for enhancing productivity is rather detrimental, in that it triggers persistent oscillations in the foliage and the population of the beetle, giving an instance of the paradox of enrichment. Some indications for biological pest control arise from the investigation of the bifurcations that occur in the model ecosystem.
The Effects of Different Charleston Pepper Cultivars on the Demographic Parameters and the Antioxidant Levels of Myzus Persicae (Sulzer, 1776) (Hemiptera: Aphididae)
(Entomological Soc Turkey, Ege Univ, 2023) Ozgokce, Mehmet Salih; Kusoglu, Duygu; Konus, Metin; Kara, Hilmi; Risvanli, Mehmet Ramazan; Cetin, Dogan
Host plant diversity causes differences in the biology and adaptation of insects. In this study, variations in some biological properties and adaptive antioxidative response of Myzus persicae (Sulzer,1776) (Hemiptera: Aphididae) on five Charleston pepper, Capsicum annuum L. (Solanaceae) cultivars were investigated under laboratory conditions (25 & PLUSMN;1 & DEG;C, 60 & PLUSMN;5% RH). The lowest intrinsic rate of increase (r = 0.193 d-1) of M. persicae was estimated in the tested cohort fed with the Kanyon cultivar, while the highest intrinsic rate of increase (r = 0.248 d-1) was found on the Tufan cultivar. The cohort fed with Safkan cultivar exhibited the highest levels of GST-CDNB and EST-PNPA at 562.80 and 207.64 nmol/mg protein, respectively, whereas the cohort fed with Kanyon cultivar showed the lowest levels at 317.04 and 132.14 nmol/mg protein, respectively. Analysis of life table parameters and enzymatic/non-enzymatic antioxidant levels of M. persicae showed that among the cultivars we tested, the Tufan cultivar was the most preferred host by M. persicae, while Kanyon cultivar was a less suitable host.
Impact of Beneficial Microorganisms Inoculated Cotton Plants on Spodoptera Exigua (Lepidoptera: Noctuidae)
(Entomological Soc Brasil, 2024) Kizilkan, Nurhan Didem; Konus, Metin; Risvanli, Mehmet Ramazan; Yilmaz, Can; Kara, Hilmi; Ozgokce, Mehmet Salih; Atlihan, Remzi
This study discusses plant-mediated effects of beneficial soil-borne microorganisms on population growth parameters of Spodoptera exigua (Lepidoptera: Noctuidae), a major cotton pest. In particular, we investigated the impact of these microorganisms on oxidative stress, chlorophyll content, and sugar and protein levels in cotton plants, and how these changes in the plant affect the survival, development, reproduction, and ultimately population growth of the pest. A longer preadult period, lower preadult survival rate, and lower reproduction were obtained for the pest cohort feeding on treated plants, which resulted in lower population parameters, i.e., intrinsic growth rate, finite growth rate, and net reproduction rate. The population projection results showed the same trend as the population parameters. These results can be attributed to the changes caused by microorganisms in the treated plants. There was no oxidative stress in the treated plants. Instead, the chlorophyll content in these plants increased, and the protein-carbohydrate ratio decreased. Additionally, we assessed the effects of plant-insect-microorganisms interaction on total glutathione levels, glutathione S-transferase, and esterase enzyme activities in S. exigua. Overall results indicate that beneficial microorganisms tested enhance the plant's ability to defend against the pest. Additionally, the findings from this study provide valuable insights into the complex interplay among plants, microorganisms, and pests, offering potential strategies for incorporating these interactions into pest management practices.
Innovative Application of Set Theory, Cartesian Product, and Multinomial Theorem in Demographic Research
(E Schweizerbartsche verlagsbuchhandlung, 2022) Chi, Hsin; Kara, Hilmi; Ozgokce, Mehmet Salih; Atlihan, Remzi; Guncan, Ali; Risvanli, Mehmet Ramazan
The bootstrap technique has been widely used to estimate the variances, standard errors, and confidence intervals (CI) of life table parameters, while the paired bootstrap test has been used to compare life table parameters between treatments by assessing the CI of differences. Although a great number of resamplings (B = 1,000 similar to 100,000) has been suggested for the application of the bootstrap technique, each computer simulation will generate different results because the bootstrap sampling with replacement is based on a stochastic process. In order to determine the theoretical and true confidence intervals of population parameters, and thereby, achieve an accurate assessment of differences between treatments, we introduce an innovative application of set theory, Cartesian product, and multinomial theorem for a mathematical formulation of demographic analysis. Moreover, when a bootstrap sample is composed of individuals that cannot produce offspring (i.e., an infertile bootstrap sample), the intrinsic rate of increase (r) and finite rate of increase (lambda) cannot be calculated. Omitting these infertile bootstrap samples will result in biased estimates. This problem of infertile bootstrap samples in demographic research has not been resolved. The integrated application of the set theory, Cartesian products, and multinomial theorem enables the detection of all possible combinations of bootstrap samples, the true CIs of population parameters, and the CIs of differences between treatments; furthermore, the probabilities of both fertile and infertile bootstrap samples can also be calculated. The life table data of the well-known cosmopolitan pest, Myzus persicae (Sulzer) (Hemiptera: Aphididac), were collected and used as examples.
A More Refined Mathematical Model for the Mycorrhiza-Potato Plant-Colorado Potato Beetle Interactions
(Elsevier, 2021) Seminara, Manuela; Atlihan, Remzi; Britton, Nicholas F.; Demir, Semra; Risvanli, Mehmet Ramazan; Venturino, Ezio
A model for the Colorado potato beetle (CPB), potato plant and mycorrhiza mutual interactions is presented, accounting for the symbiotic and predator-prey features of this system. The study is performed to determine if arbuscular mycorrhizal fungi (AMF) increase potato tolerance to CPB. To this end, data collected by biological experiments are used. The system exhibits several possible equilibria that are related to each other via bifurcations. The latter are investigated both analytically and through simulations. The results indicate that the use of mycorrhiza is effective in keeping the pest population at low levels.
Salkım Güvesi [Lobesia Botrana Denis & Schiffermüller (Lepidoptera: Tortricidae)]'nin Midyat Bağ Alanlarındaki Ergin Popülasyon Dinamiği
(2023) Argış, Fuat; Risvanli, Mehmet Ramazan; Atlıhan, Remzi
Bu çalışma Salkım güvesi [Lobesia botrana Denis & Schiffermüller (Lepidoptera: Tortricidae)]’nin ergin popülasyon değişimi, doğada aktif olarak bulunduğu süre ve döl sayısının belirlenmesi amacıyla yapılmıştır. Çalışma, 2014 ve 2015 yılları arasında Mardin ilinin Midyat ilçesindeki bağlarda yaygın olarak yetiştirilen yerel ‘Mazruni’ üzüm çeşidi üzerinde yürütülmüştür. Çalışma sonucunda, her iki yılda da L. botrana popülasyonunun yüksek yoğunluğa (2014 yılında ortalama 2173 ergin/tuzak ve 2015 yılında 1615 ergin/tuzak) sahip olduğu ve eşeysel çekici tuzaklarda kelebeklerin ilk olarak Nisan başında görüldüğü belirlenmiştir. Elde edilen sonuçlara göre, zararlının üç döl verdiği ve bağın fenolojisi boyunca üç veya dört tepe noktası (sezon boyunca ana üç tepe noktası ve sezon sonunda zayıf bir tepe noktası) oluşturduğu tespit edilmiştir. Bu tepe noktalardan birincisi çiçek dönemine (8-16 Mayıs), ikincisi koruk (nohut büyüklüğü) dönemine (27 Haziran-6 Temmuz) üçüncüsü tanelerin tatlanma (ben düşme) dönemine (27 Temmuz- 15 Ağustos) dördüncüsü de tatlanma-hasat dönemine (17-19 Eylül) denk gelmektedir. Çalışma sonucunda zararlının kışlamaya Ekim ayı sonu ile Kasım ayı başları arasında girdiği, doğada yaklaşık olarak yedi ay aktif kaldığı gözlenmiştir. Elde edilen sonuçlar, zararlı ile mücadeledenin uygun zamanda yapılabilmesine yardımcı olan temel bilgileri sağlamaktadır.