Establishing the existance of entomopatogenic nematodes in soil samples from corn crops and potatoes

Abstract

Nematode se mogu naći u gotovo svim ekološkim sustavima na kopnu, slatkoj vodi ili moru. Entomopatogene nematode (EPN) su mikroskopski jednostavni organizmi koji žive u tlu, a imaju sposobnost parazitacije velikog broja kukaca. Svrstane su u devet porodica, ali samo su porodice Heterorhabditidae, Mermithidae i Steinernematidae letalne za kukce. Nematode se nalaze u mutualističkom odnosu s bakterijama iz dvije porodice Enterobacteriaceae, čineći pri tome snažan insekticidni kompleks. Mogu se uzgajati in vivo ili in vitro, lako se ispuštaju u prirodu, same se obnavljaju, pa osiguravaju suzbijanje kroz duže razdoblje i nisu opasne za korisne organizme, a prihvatljive su za okoliš. Cilj ovog diplomskog rada bio je utvrditi prisutnost EPN u uzorcima tla prikupljenima u usjevima kukuruza i krumpira. Uzorci tla prikupljani su od srpnja do kolovoza 2017. na osam lokaliteta kontinentalne Hrvatske. U laboratorijskim uvjetima i na hranidbenim podlogama, uzgajane su ličinke voskovog moljca koje služe kao mamci u postupku izolacije EPN iz uzoraka tla. Analizirano je 40 uzoraka. EPN nisu utvrđene niti u jednom uzorku tla prikupljenom u usjevima krumpira, kukuruza te ostalim usjevima. Istraživanje je potrebno nastaviti s tendencijom prikupljanja većeg broja uzoraka, na većem broju lokaliteta.Nematodes can be found in almost all ecological systems on land, fresh water or the sea. Entomopathogenic nematodes (EPNs) are microscopically simple organisms living in the soil and have the ability to parasitize a large number of insects. They are classified into nine families, but only the families of Heterorhabditidae, Mermithidae and Steinernematidae are lethal for insects. Nematodes are found in the mutualistic relationship with bacteria from two Enterobacteriaceae families, with a strong insecticide complex. They can be grown in vivo or in vitro, are easily released into nature, are rejuvenated, and are suppressed for a longer period of time and are not dangerous to beneficial organisms and are environmentally friendly. The aim of this graduate thesis was to establish the presence of EPN in soil samples collected in corn and potato crops. Soil samples were collected from July to August 2017 to eight continental Croatia localities. In laboratory conditions and on nutrient substrates, larvae of wax moth mites used as bait in the EPN isolation process from soil samples were grown. 40 samples were analyzed. EPN were not found in any sample of soil collected in potato, corn, and other crops. The research needs to continue with the tendency to collect more samples on a large number of localities