İlker Kepenekçi

Evaluation of entomopathogenic nematodes and the supernatants of the in vitro culture medium of their mutualistic bacteria for the control of the root-knot nematodes Meloidogyne incognita and M. arenaria.

BACKGROUND The suppressive effects of various formulations of four entomopathogenic nematode (EPN) species and the supernatants of their mutualistic bacteria on the root-knot nematodes (RKNs) Meloidogyne incognita and M. arenaria in tomato roots were evaluated. The EPNs Steinernema carpocapsae, S. feltiae, S. glaseri and Heterorhabditis bacteriophora were applied as either live infective juveniles (IJs) or infected insect cadavers. Spent medium from culturing the bacterial symbionts Xenorhabdus bovienii and Photorhabdus luminescens kayaii with the cells removed was also applied without their nematode partners. RESULTS The aqueous suspensions of IJs, infected cadaver applications of EPNs and especially treatments of X. bovienii supernatant suppressed the negative impact of RKNs on tomatoes. Specific responses to treatment were reduced RKN egg masses, increased plant height and increased fresh and dry weights compared with the control where only RKNs were applied. CONCLUSION Among the treatments tested, the plant-dipping method of X. bovienii into bacterial culture fluid may be the most practical and effective method for M. incognita and M. arenaria control.

Biological control potential of Turkish entomopathogenic nematodes against the Colorado potato beetle, Leptinotarsa decemlineata

ABSTRACT Three Turkish isolates of the entomopathogenic nematodes Steinernema carpocapsae, Steinernema feltiae and Heterorhabditis bacteriophora were evaluated under laboratory conditions (in different temperatures and doses) for their biocontrol efficiency against last instar Leptinotarsa decemlineata. Herein, the effects of infective juveniles in aqueous suspension against L. decemlineata were evaluated. S. feltiae appeared to be the most pathogenic nematode among the tested species.

Effect of Purpureocillium lilacinum on Root Lesion Nematode, Pratylenchus thornei

Wheat (Triticum spp.) is highly susceptible to the root lesion nematode, Pratylenchus thornei, which causes excessive amounts of crop losses each year. In this research, we investigated the cumulative effect of the biocontrol agent Purpureocillium lilacinum (syn: Paecilomyces lilacinus) against P. thornei. Three doses of P. lilacinum (106, 107 and 108 conidia cultures mL-1) with one dose of 400 P. thornei individuals (adults and juveniles) mL-1 were applied in 100 cm3 soil under greenhouse conditions. The number of nematodes in the soil and root in addition to total nematode in soil+root were determined. Moreover, different plant parameters such as the plant height, plant fresh and dry weight, root fresh and dry weight were evaluated. Applications with the higher dose of bio-agents (100 cm3 P. thornei infested soil with 108 conidia culture of P. lilacinum mL-1) exhibited maximal enhancement in dry and fresh weight of shoot and reduced P. thornei population. As a consequence, P. lilacinum individually was highly effective in enhancing different plant parameters and suppressing P. thornei reproduction. Overall, present findings suggest that the exploitation of the biocontrol agent P. lilacinum could be helpful for effective management of the root lesion nematode P. thornei.

Evaluation of entomopathogenic fungi, Purpureocillium lilacinum TR1 for the control of the Root-knot nematodes (Meloidogyne javanica, M. incognita and M. arenaria)

Kok-ur nematod lari (KUN) (Nematoda: Meloidogynidae)’lari sebzelerin en onemli zararlilarindandir. Turkiye’de daha cok kiyi kesimlerinde seralarda yetistirilen sebzelerde daha cok ve yogun olarak gorulmektedir. Ticari nematisitler cevre ve insan sagligina yuksek oranda toksik olduklarindan alternatif mucadele yontemlerine ihtiyac vardir. Bu metotlar arasinda en etkili ve cevre dostu olan yontemler icerisinde entomopatojen fungus (EPF)’larin kullanimi onemli bir yer tutmaktadir. Bu calismada KUN [Meloidogyne arenaria (Neal) Chitwood, M. incognita (Kofoid & White) Chitwood ve M. javanica (Treub) Chitwood]’lerin mucadelesinde Purpureocillium lilacinum TR1 (syn: Paecilomyces lilacinus (Thom) Luangsa-ard, Houbraken, Hywel-Jones & Samson) (Hypocreales: Ophiocordycipitaceae)’in Turk izolatinin kullanim olanagi degerlendirilmistir. Denemeler plastik saksilarda yurutulmus ve KUN’lerin 3000 yumurta ve 1000 L2 donemleri topragin 2 cm derinligine uygulanmistir. P. ilacinum, hemasitometrede 106, 107 ve 108 cfu ml-1 konsantrasyonda konidi sayimlari yapilarak hazirlanmistir. Pozitif kontrol KUN yumurtalari veya L2’leri icermekte, negatif kontrol de ise KUN bulunmamaktadir. Denemeler her uygulama icin 5 tekerrurlu olarak yurutulmustur. Her bitkideki toplam yumurta sayisi, bitki uzunlugu, bitki ust kisimlarinin kuru ve yas agirligi ile kok yas ve kuru agirligi kaydedilmistir. Deneme sonuclarina gore nematod sayisi inokulum yogunlugunun artisina bagli olarak azalmistir. Purpureocillium lilacinum TR1‘in 108 cfu konsantrasyonu diger konsantrasyonlardan daha etkili bulunmustur.

Ülkemiz için yeni bir kök-ur nematodu türü, Meloidogyne exigua Göldi'nın taksonomik özellikleri ve diğer kök-ur nematodu türleri

Calismada Eskisehir, Isparta, Burdur ve Antalya Illerinde ortu alti sebze uretimi yapilan alanlar nematolojik acidan incelenmistir. Alinan orneklerden elde edilen bitki paraziti nematod turleri icerisinde onemli bir yere sahip olan kok-ur nematodlari ( Meloidogyne spp.)’nin turleri belirlenmistir. Inceleme sonucunda sozkonusu yorelerde varligi bilinen 3 Kok-ur nematodu turunun [M. incognita (Kofoid and White) Chitwood, M. hapla Chitwood ve M. javanica (Treub) Chitwood] yanisira Turkiye nematod faunasi icin yeni bir tur olan M. exigua (Goldi) Chitwood saptanmistir. Calismada M. exigua’nin taksonomik (morfolojik ve morfometrik) ozellikleri verilmistir.

Entomopatojen nematodların ağ kurdu [ Yponomeuta mallinellus Zell. ve Yponomeuta padella L. (Lepidoptera: Yponomeutidae)] larvalarına etkileri

p>The species of Steinernema , Neosteinernema (Rhabditida: Steinernematidae) and Heterorhabditis (Rhabditida: Heterorhabditidae ) have more important role than the other nematod groups in biological control of the insect pests. In this study, the effects of Steinernema feltiae (Tur-S3) , S. feltiae (All type) , Heterorhabditis bacteriophora (Tur-H1) and H. bacteriophora (Tur-H2), which are EPN isolates of Turkey, were investigated against larvae of Yponomeuta mallinellus Zell.and Y. padella L.(Lepidoptera: Yyponomeutidae) in laboratory conditions. The experiments were carried out in plastic 12-cell-well (plate) with 24mm in diameter, 20mm depth. Mortality records were taken after 96 h and corrected according to Abbots formula versus a control treatment contained only Yponomeutid moth larvae in distilled water. According to the results, average mortality rates of Y. mallinellus were 33.3%; 38.8%; 49.9% and 63.82% for S. feltiae (All type), H. bacteriophora (Tur-H1), S. feltiae (Tur-S3) and H. bacteriophora (Tur-H2), respectively. Average mortality rates of Y. padella were38.8%; 49.9% and 88.8% for S. feltiae (All type); same mortality H. bacteriophora (Tur-H1) and S. feltiae (Tur-S3); H. bacteriophora (Tur-H2), respectively. The mortality rates, i.e. the effects were found to be higher in Y.mallinellus and Y. padella which was the highest with H. bacteriophora (Tur-H2). No mortality was observed in control. In further studies, applications of EPN are needed for controlling Y. mallinellus and Y. padella in the orchards.