Study of Pasteuria penetrans group on some plant parasitic nematodes and their host ranges in the north of Iran
Maafi, Z.Tanha
Iranian Journal of Plant Pathology 36(3-4): 65-68
2000
Accession: 011416141
A survey of sixty soil and root samples collected from the rhizosphere of citrus and kiwifruit orchards; tea plantations and cultivated plants from different regions of Gilan and Mazandaran provinces revealed that isolates of P. penetrans group actively exist in the north of Iran and naturally parasitize a number of plant parasitic nematodes. Three different isolates of this group of bacteria were found on the basis of host, reproduction and size of spores. The first isolate type was observed on Helicotylenchus pseudorobustus, H. dihystera and H. digonichus in which some specimens were infected over eighty percent and the body fully occupied by endospores of the bacterium. The diameter and the central core in this isolate were 4-5 mmu (4.7) and 2-2.1(2) mmu, respectively, and were lager in comparison with the other isolates. The diameter and the central core of the second isolate observed on Boleodorus thylactus and Paratylenchus sp. were 2.2-3(2.88) mmu and 0.9-1.2(1) mmu which was as large as the citrus nematode isolate except for its developmental stages. The latter completes its developmental stages in male and second stage juveniles of citrus nematode but not in adult female. The third group of isolates which were obtained from Meloidogyne incognita race 2 and M. arenaria races 1 and 2 reproduced on these species, possessed an endospores 3-4(3.85) mmu and central core of 1-1.2(1.16) mmu in diameter. The host ranges of the isolates from the root knot and the citrus nematodes were tested on a number of plant parasitic nematodes. In either spore infested soil or water suspension (Oostendrop et al. 1990, Stirling and Watchel 1980), none of the isolates could attach to the males or second stage juveniles of the citrus nematode. The isolate obtained from M. arenaria race 1 in water suspension attached to all Meloidogyne and Pratylenchus zeae tested and showed the widest host range. The tested isolates did not attach to second stage juveniles of Heterodera schachtii, P. loosi or Ditylenchus dipsaci.