Cotton (Gossypium spp.) is the best plant fiber source in the world and provides the raw material for industry. Verticillium wilt caused by Verticillium dahliae Kleb. is accepted as a major disease of cotton production. The most practical way to deal with verticillium wilt is to develop resistant/tolerant varieties after cultural practices. One of the effective selections in plant breeding is the use of marker-assisted selection (MAS) via quantitative trait loci (QTL). Therefore, in this study, we aimed to discover the genetic markers associated with the disease. Through the association mapping analysis, common single nucleotide polymorphism (SNP) markers were obtained using 4730 SNP alleles. As a result, twenty-three markers were associated with defoliating (PYDV6 isolate) pathotype, twenty-one markers with non-defoliating (Vd11 isolate) pathotype, ten QTL with Disease Severity Index (DSI) of the leaves at the 50–60% boll opening period and eight markers were associated with DSI in the stem section. Some of the markers that show significant associations are located on protein coding genes such as protein Mpv17-like, 21 kDa protein-like, transcription factor MYB113-like, protein dehydration-induced 19 homolog 3-like, F-box protein CPR30-like, extracellular ribonuclease LE-like, putative E3 ubiquitin-protein ligase LIN, pentatricopeptide repeat-containing protein At3g62890-like, fructose-1,6-bisphosphatase, tubby-like F-box protein 8, endoglucanase 16-like, glucose-6-phosphate/phosphate translocator 2, metal tolerance protein 11-like, VAN3-binding protein-like, transformation/transcription domain-associated protein-like, pyruvate kinase isozyme A, ethylene-responsive transcription factor CRF2-like, molybdate transporter 2-like, IRK-interacting protein-like, glycosylphosphatidylinositol anchor attachment 1 protein, U3 small nucleolar RNA-associated protein 4-like, microtubule-associated protein futsch-like, transport and Golgi organization 2 homolog, splicing factor 3B subunit 3-like, mediator of RNA polymerase II transcription subunit 15a-like, putative ankyrin repeat protein, and protein networked 1D-like. It has been reported in previous studies that most of these genes are associated with biotic and abiotic stress factors. As a result, once validated, it would be possible to use the markers obtained in the study in Marker Assisted Selection (MAS) breeding.

Background: Verticillium dahliae Kleb. is a soil-borne pathogen with a broad host spectrum and causes yield losses in cotton cultivation worldwide. Beauveria bassiana is an environmentally friendly entomopathogenic fungus (EPF) that has been recognized, used and studied for many years. Results: As a control, all local of B. bassiana isolates inhibited mycelial growth of the pathogen at different rates. The highest percentage of inhibition against non-defoliating (PHCVd3 isolate) and defoliating (PHCVd47 isolate) pathotypes was determined in Bb18 (85.3; 81.7%) and Bb1 (82.3; 77.5%) isolates, respectively, when applied 2 days ago. Isolates Bb1 (80.6%) and Bb18 (77.8%) had the highest percentages of inhibition against the PHCVd3 isolate, and Bb18 (75.8%) against isolate PHCVd47, when EPF and pathogen were applied at the same time. Conclusions: Bb18 and Bb1 isolates of B. bassiana showed a hope against both pathotypes of wilt disease caused by V. dahliae under in vitro conditions. Especially, B. bassiana was observed to induce higher inhibition rates, when EPF isolates developed in Petri dish 2 days before the pathogen.

Beauveria bassiana (Balsamo) Vuillemin is one of the entomopathogenic fungi used against broad host insects and plant pathogens. Fungicides have side effects on entomopathogenic fungi. In vitro assay was performed to examine the compatibility of B. bassiana with eight commonly used fungicides (Azoxystrobin 75 g/l+Metalaxyl-m 37.5 g/l+ Fludioxonil 12.5 g/l FS, Boscalid 25%+ Pyraclostrobin 12% WG, Copper Hydroxide 361.1 g/l SC, Azoxystrobin 250 g/l SC, Triticonazole 80 g/l + Pyraclostrobin 40 g/l FS, Fludioxonil 12.5 g/l + Metalaxyl 10 g/l SC, Captan 50% WP, Tebuconazole 250 g/l EC) using contact application technique. Fungicides at various concentrations (Recommend Dose-RD, half of the Recommend Dose-0.5 x RD and twice the Recommend Dose-2 x RD) were mixed in Potato Dextrose Agar (PDA) media post-autoclaving. Approximately 25 ml of the mixture was poured into a Petri dish (90 mm) and allowed to cool. Mycelium disc (5 mm in diameter) was taken from 14-days-old B. bassiana grown on PDA using a sterile cork borer and placed in the center of each Petri dish containing fungicide + PDA. PDA plates without fungicide were used as a control. Petri dishes were incubated in the dark at 25±1 °C for 14 days. In vitro experiments were carried out with three replicates depending on a completely randomized plots design. In the study, the compatible fungicide with B. bassiana ET 10 isolate was found to be Copper Hydroxide at 0.5 x RD concentration. Azoxystrobin and Copper Hydroxide were compatible with Bb 18 isolate. Only two (Azoxystrobin + Metalaxyl-m + Fludioxonil and Tebuconazole) of the eight fungicides completely inhibited the mycelial growth of ET 10 isolate and were found harmful. Azoxystrobin + Metalaxyl-m + Fludioxonil completely inhibited the growth of Bb 18 isolate and was not found compatible. This study clearly shows that fungicides have the potential to inhibit the mycelial growth of entomopathogenic fungi under in vitro conditions. However, these results need to be further verified in vitro under both greenhouse and open-field conditions.

The dried fruit moth, Plodia interpunctella (Hübner, 1813) (Lepidoptera: Pyralidae) is one of the most important pests of both dried fruits and stored grains and products. One of the alternative control methods to chemicals in the control against this pest is the use of biological control methods. Entomopathogenic fungi (EPF) stand out because they do not have any negative effects on the environment, living organism and human health, other than the target pests. In this study, ET 10 and Bb 18 isolates of Beauveria bassiana (Bals.) Vuill. were applied to the 4th instar larvae of P. interpunctella under laboratory conditions and their effectiveness was determined. EPF isolates were sprayed to the larvae in plastic petri dishes at a concentration of 1x108 conidia/ml. The experiments were carried out in a randomized plots experimental design with five replicates, with five 4th instar larvae in each petri dish. After the applications, the number of live larvae was recorded by counting the 1st, 3rd, 5th and 7th days and the % mortality rate was calculated. On the fifth day of the experiment, mortality rates of 92% were recorded for the ET 10 isolate of B. bassiana and 84% for the Bb 18 isolate. In the seventh day counts, 100% mortality rates were determined for both isolates of B. bassiana. As a result, it is concluded that B. bassiana may have a potential effect in the biological control of stored product pests.

Yield losses are experienced in corn fields due to stalk and ear rot disease. The fungicides used against the disease can not show the desired effect and the problem of resistance arises over time. For this reason, it is necessary to develop new strategies in the control against the disease. In this study, it was aim to determine the inhibitory effects of essential oils of rosemary, black cumin, cumin and sandalwood, and ginger against Fusarium verticillioides and Fusarium pseudograminearum under in vitro conditions. The essential oils were applied in doses of 0.25, 0.5, 1, 2 and 4 µl mL-1. PDA medium free of essential oils was used as negative control and PDA medium containing commercial fungicide (80 g l-1 Triticonazole, 40 g l-1 Pyraclostrobin-BASF company) was used as positive control. The experiment was carried out in a randomized plot design with three replications. In addition, chemical content analysis of essential oils was determined by GC-MS method. As a result of the study, as the dose of rosemary, black cumin, sandalwood and ginger essential oils increased, their inhibitory effects against both pathogens increased, and these effects were found close to each other. While the highest inhibitory effect against F. verticillioides and F. pseudograminearum was detected in the positive control treatment of cumin essential oil, 82.1% and 78.9%, respectively, this effect was found to be 74.6% and 68.3% in 4 µl mL-1 dose, respectively. However, more detailed studies should be carried out with these essential oils under field conditions.

The use of natural products in the control of fungal diseases in plants is considered an alternative to synthetic fungicides due to their less negative effects on the environment. In this study, in vitro inhibitory effect of plant essential oils (PEOs) of black cumin, cumin, chamomile, cedarwood, and ginger were investigated for controlling two species of Alternaria, including Alternari solani and Alternaria alternata on tomato and cabbage under in vitro conditions, respectively. Aiming to evaluate the mycelial growth of the pathogen, mycelial discs were placed in Petri plates with 0, 500, 1000, 1500, 2000, and 2500 μL/L of PEOs. The experiment was carried out in a randomized plot design with three replications. Chemical analysis of PEO components were determined by Gas Chromatography and Mass Spectrometry methods. A total of 69 chemical compounds were determined in five different PEOs. As the main chemical compounds, Cuminaldehyde was detected in cumin PEO, Sesquithujene was found in ginger PEO, and Eucalyptol (1,8-cineole) was determined in black cumin, chamomile, and cedarwood PEOs. All five PEOs were found to inhibit the growth of Alternaria species in a dose-dependent manner, whereas cumin EO was determined more inhibitory effect against A. solani and A. alternata. Cumin PEO showed the highest effect against Alternaria species because it contains a Cuminaldehyde chemical compound. The lowest inhibition percentage was found in chamomile PEO compared to other PEOs. This study suggested that cumin PEO has the potential as an antifungal agent for controlling of Alternaria diseases.