Search

Fusarium oxysporum Schlecht. f.sp. melongenae (FOM), Verticillium dahliae (Ve) and Ralstonia solanacearum are major limiting pathogens affecting eggplant cultivation and their yield in the world. Natural resistance genes are the most environmentally friendly method to control the disease. Thus, marker-assisted selection (MAS) is preferred as a tool for screening resistance genes (R-genes) in eggplant resistance breeding. In this study, markers that are specifically linked to major disease resistance genes conferring resistance to F. melongenae, V. dahliae and R. solanacearum were tested in a population containing breeding materials to validate the resistance. Resistant Solanum melongena accessions LS1934 and LS2436 and their reciprocal crosses were used as the resistance resource for this validation study. Moreover, classical resistance tests to FOM and Ve were performed with the root-dip inoculation method for classification of all the accessions based on their resistance/susceptibility responses. The SCAR426, CAPs_903 and SIVR844 markers were highly informative for the determination of resistance genes (Fomg, Ve and ERs1). Therefore, in areas with high susceptibility to diseases, a highly efficient combination of the relevant R-genes and their pyramiding into commercial eggplant varieties are proposed to be implemented as a pragmatic approach.

Abstract Background Aggressive biotype (Trichoderma aggressivum f. aggressivum) of green mold is one of the main biotic factors limiting button mushroom (Agaricus bisporus) cultivation. Due to issues such as fungicide resistance, cost, and adverse effects, biological control seems to be an applicable management method against the green mold in button mushroom cultivation. Results The objective of the study was to assess biological control of green mold in button mushroom cultivation. Five native bacterial isolates from mushroom compost and 3 commercial biological preparations were tested against two isolates of T. aggressivum f. aggressivum. Dual culture tests were used in vitro experiments. In vivo, compost and casing soil experiments were conducted by comparing yield values of treated plots with negative and positive controls. In vitro, the bacterial isolates inhibited mycelial growth of isolates of T. aggressivum f. aggressivum and A. bisporus up to 46.60 and 56.94%, respectively. In vivo, in the compost experiment, compared with positive control plots, bacterial isolate MSG-5 (Bacillus subtilis) caused the highest yield increase (40.56%) in the treatments. In the casing soil experiment, commercial biological preparation Tic-3 (Ampelomyces quisqualis) caused the highest yield increase (36.15%) in the treated plots. Compared with positive and negative controls, all the treatments caused 30.23% increase but 4.86% decrease in yield of A. bisporus in the compost experiment, respectively. However, they caused 20.25% increase but 17.33% decrease in the yield of A. bisporus in the casing soil experiment, respectively. Conclusions Results suggested that biological control of the green mold in compost can be more efficient than casing soil in button mushroom cultivation.

Abstract Macrophomina phaseolina is a polyphagous fungus causing substantial yield losses in many plant species. In 2017, M. phaseolina was found to be causal agent of wilting and stunting symptoms of globe artichoke (Cynara scolymus) in the Mediterranean region of Turkey. There is no knowledge about M. phaseolina in globe artichoke and applicable management practice in cultivation of the crop. In the present study, the causal agent was characterized in vitro and in vivo studies. Pathogenicity tests were carried out using seedlings of globe artichoke and nine plant species (sunflower, chickpea, soybean, sesame, peanut, wheat, maize, cotton and sorghum) in a greenhouse. In addition, five inoculation techniques were assessed to determine the most suitable method for screening resistance to M. phaseolina in globe artichoke. Significant (P˂0.01) variations were found among the inoculation techniques. Depending on each inoculation technique, death of lateral roots and distinct lesions up to 5.38 cm occurred on primary roots and crowns of globe artichoke. M. phaseolina also caused lesions ranging from 1.43 to 9.63 cm on primary roots including crown and stems of tested plant species. M. phaseolina was pathogenic to globe artichoke and all the tested plant species, confirming its polyphagous nature. This is the first record of M. phaseolina causing root and crown rot in globe artichoke in the world. Moreover, the present study suggested that toothpick inoculation technique could be used for screening resistance to M. phaseolina in globe artichoke.

Botrytis cinerea (teleomorph: Botryotinia fuckeliana) causes gray mold disease on vegetable crops in greenhouses. Profound knowledge on pathogen diversity is necessary for efficiently disease management. In this study, forty-two B. cinerea isolates collected from 36 different greenhouses in Antalya province of Turkey were investigated. Twelve SRAP (sequence-related amplified polymorphism) and 18 ISSR (inter simple sequence repeat) primers producing high polymorphic fragments were used to genetic diversity of B. cinerea isolates infecting dill, basil, lettuce, bean, cucumber, tomato, pepper and eggplant. The unweighted pair-group method with arithmetic average analysis (UPGMA) was used to evaluate of combined ISSR and SRAP data showing a similarity range 0.15-0.90 among the isolates. Cophenetic correlation of the tree was high level (r=0.93). Interestingly, cluster analysis showed a divergent group consisting of lettuce isolates which were genetically different from the other isolates. On the other hand, transposable elements (Flipper and Boty) were detected among isolates from all the hosts. Isolates containing only the Fliper element were detected. The results showed that genetically characterized B. cinerea populations by a high level of genetic diversity were associated with genotype flow and the evolutionary potential of B. cinerea. In further studies, the newly tested molecular markers are useful and can be suggested for analyzing of genetic diversity and population structure of this pathogen on different hosts.

The host resistance level of pure line materials was assessed in the genepool for the purpose of breeding. The highest resistance to the pathogen was observed in bell-type pepper. Moreover, genetic diversity of pure lines was investigated using selected inter-simple sequence repeat (ISSR) primers. Generally, genetic markers showed genetic diversity, so that long-type pure lines were separated from the other accessions. This is the first report on host reactions of Turkish pure lines as breeding material. These results provide significant information for future pepper breeding programs.

Pepper is widely grown vegetable crops after tomato and watermelon in the world. One of the most important diseases on pepper production is caused by Tomato spotted wilt virus (TSWV). The best way for the control of this disease is to use resistant varieties. This study aimed to improve TSWV resistant lines to use as a parent in long type pepper breeding studies. Three genotypes resistant to TSWV were crossed with the susceptible Serademre 8 used to be commercial. Pedigree method was applied as the breeding method. Three populations were self-pollinated for five generations. The progenies for each of populations were tested against TSWV. Mechanical inoculations were performed in each generation and the selected resistant plants were grown for self-pollination to achieve next generation. Molecular tests were applied to the plants in stages F1 and F5. Virulent strain isolated from infected pepper plants was used as a disease material in the mechanical inoculations. CAPS marker (SCAC568) linked to the TSWV resistance gene (Tsw) was used in the molecular test for verification of mechanical test. In this study, 10 lines resistant to TSWV with good features were developed. Some of the obtained TSWV resistant lines have been transferred to private sector seed companies for use in pepper breeding programs.

Fusarium oxysporum f. sp. melonis (FOM) is one of the most important fungal diseases in melon cultivation. The four races called 0, 1, 2 and 1-2 for FOM have been identified. Although all of FOM races are seen in our country, races 1 and 2 are the most common. Fungicides are used to provide control of this disease. However, fungicides don’t provide permanent protection. Therefore, resistant varieties are used to provide an alternative to fungicides and a certain protection against the disease. In this study, yields and resistances to FOM of 8 melon Fl hybrids developed in the melon breeding program of BATEM (Batı Akdeniz Agricultural Research Institute) were determined. In molecular studies, SSR154 primer was used to determination of disease resistance for race 0 and 1 and NBS1-CAPS primer was used for race 2 of FOM. As a result, this study showed that FÇ 98 hybrid variety had a yield potential close to Cıtırex F1 hybrid variety and leading among the other candidate varieties. This promising hybrid variety has been presented to vegetable growers.

Pepper (Capsicum annuum L.), is one of the most important vegetable species produced both in the world and in Turkey. Turkey is in third place in pepper production in the world. There are many viruses affecting and limiting pepper production. Potato Y virus (PVY), a member of the genus potyvirus, is one of the most common viruses infecting pepper crops. Improving resistant pepper varieties against the disease is more advantageous and easy way to control disease in production area. There are 4 races such as PVY0, PVY1 and PVY1-2 in the world. The dominant Pvr4 resistance gene in wild type SCM 334 pepper confers a complete resistance to the three pathotypes of potato virus. In this study, resistant genotype SCM 334 and susceptible long pepper inbred line were crossed to improve resistance in breeding lines. To eliminate the undesirable characteristics of the resistant genotypes, resistant line was backcrossed three times with susceptible genotypes. Mechanical inoculation and molecular methods were used to determine the reaction of backcross progenies to the disease. The dominant CAPS markers were used to determine resistant and susceptible plants and results from the mechanical inoculation method were verified with the CAPS marker. This study is a part of “Improvement of F1 Hybrid Vegetable Varieties and Qualified Lines in Turkey” basic project and financed by Scientific and Technological Research Council of Turkey (TUBITAK-KAMAG 109G029).