ABSTRAK
Kapang rizosfer mempunyai kemampuan menghambatFusarium oxysporum f.sp. lycopersici (Sacc.) W.C. Snyder & H.N. Hans.penyebab penyakit layu pada tanaman tomat (Lycopersicon esculetum Mill.).Kapang rizosfer diisolasi dari daerah perakaran tanaman tomat di lahankonvensional Desa Cikahuripan dan Sukamulya, Sukabumi. Tujuh belas spesiesyang antagonis terhadap F. oxysporum f.sp. lycopersici telah diidentifikasi dari 47isolat yang diisolasi dan 2 isolat koleksi LIPI MC. Mekanisme antagonis untukmengendalikan patogen terlihat beragam dari tiap spesies kapang rizosfer.Kompetisi dengan kapang patogen terlihat pada Trichoderma sp. dan Mucor sp.Semua isolat kapang rizosfer memproduksi agen antifungi volatil bukan HCN dantidak dapat memproduksi enzim kitinase. Kapang rizosfer memproduksi agenantifungi non-volatil iturin yaitu Aspergillus fumigatus Fres., Aspergillus nigerVan Tieghem, dan 2 isolat Aspergillus sp. Enzim protease diproduksi olehA. fumigatus, Aspergillus sp., Fusarium oxysporum Schlecht, danHumicola fuscoatra Traaen. Aspergillus niger dan Penicillium sp., merupakankapang rizosfer yang memproduksi agen antifungi non-volatil dan volatil terhadappatogen. Baik pada suspensi konidia patogen yang disimpan 4° C dan tidakdisimpan dalam lemari pendingin yang diberi agen antifungi non-volatilAspergillus niger (1:1) memperlihatkan persentase hambatan pertumbuhankonidia patogen tertinggi masing-masing 77,97 % dan 76,08 % pada pengamatanjam ke-8. Agen antifungi non-volatil Aspergillus niger pada berbagai konsentrasimeningkatkan perkecambahan tomat masing-masing 4,17 % pada benih tomatyang diberi filtrat atau suspensi konidia patogen yang diinkubasi selama 30 menit.Sedangkan waktu inkubasi 60 menit, agen antifungi non-volatil A. niger padaberbagai konsentrasi meningkatkan perkecambahan tomat 5,25 %?21,04 % padabenih tomat yang diberi suspensi konidia patogen dan menurunkanperkecambahan tomat 6,38 %?13,04 % pada benih tomat yang diberi filtratpatogen. Perpanjangan waktu inkubasi 30 menit menghambat selama 4 harikolonisasi patogen pada tomat yang diberi campuran filtrat atau suspensi konidiapatogen dan agen antifungi non-volatil A. niger pada berbagai konsentrasi. Agenantifungi volatil dari Penicillium sp. dapat menghambat perkecambahan konidiapatogen sebesar 22,07 %.
Abstract
Rhizosphere moulds have activities to reduce the growth of Fusariumoxysporum f.sp. lycopersici (Sacc.) W.C. Snyder & H.N. Hans, the causalpathogen of wilt disease of tomato (Lycopersicon esculentum Mill.) plant.Moulds were isolated from rhizosphere of tomato plants growing in the Villagesof Cikahuripan and Sukamulya, Sukabumi. Seventeen species that haveantagonistic effect to F. oxysporum f.sp. lycopersici were identified from 47isolates isolated from rhizosphere of tomato plant and 2 isolates of LIPI MCcollection. Antagonistic mechanism for control the pathogen seemed differentfrom each species of the rhizosphere moulds. Competition with the pathogen wasproduced by Trichoderma sp. and Mucor sp. All isolates of the rhizospheremoulds produced non-HCN volatile antifungal agent and did not producedchitinase enzyme. Rhizosphere moulds that produced iturin non-volatileantifungal agent were Aspergillus fumigatus Fres., Aspergillus niger VanTieghem, and 2 isolates of Aspergillus sp. Protease enzyme was produced byA. fumigatus, Aspergillus sp., Fusarium oxysporum Schlecht, andHumicola fuscoatra Traaen. Aspergillus niger and Penicillium sp. wererhizophere moulds that produced non-volatile and volatile antifungal agentsrespectively against the pathogen. Both on the suspension of the pathogen conidiastored in 4° C and unstored in refregerator that given non-volatile antifungal agentof A. niger (1 : 1) showed the highest percent inhibition of the pathogen conidiarespectively 77.97 % and 76.08 % in observation to-8 hours. Non-volatileantifungal agent of A. niger at various consentrations increased the germination oftomato respectively at 4.17 % on tomato that given the filtrate or suspension ofconidia of the patogen at 30 minutes incubation. While in the incubation time of60 minutes, non-volatile antifungal agent of A. niger at various concentrationincreased the germination of tomato at 5.25 %─21.04 % on tomato that givensuspension of conidia of the pathogen and decreased the germination of tomato at6.38 %─13.04 % on tomato that given the pathogen filtrate. Extending ofincubation time for 30 minutes 4 days delayed the colonization of the pathogen ontomato that given a mixture of the filtrate or the suspension of the pathogenconidia and non-volatil antifungal agent of A. niger at various concentrations.The volatile antifungal agent of Penicillium sp. decreased the germination ofconidia of the patogen at 22.07 %. |
