Potensi Cendawan Endofit Nigrospora sp. dalam Menekan Penyakit Blas (Pyricularia oryzae) pada Tanaman Padi

Abstract

Penyakit blas (Pyricularia oryzae) merupakan salah satu penyakit penting pada tanaman padi yang dapat menyebabkan kehilangan hasil antara 1-50% di dunia. Pengendalian penyakit blas dengan menggunakan varietas tahan dan penggunaan fungisida dinilai masih belum efektif karena variasi genetik penyebabnya yang tinggi. Pengendalian hayati diharapkan mampu menjadi alternatif untuk menekan cendawan ini salah satu diantaranya menggunakan cendawan endofit. Penelitian ini bertujuan menguji potensi cendawan endofit Nigrospora sp. dalam menekan penyakit blas yang disebabkan P. oryzae. Penelitian dilaksanakan di CV. WiSH Indonesia dari bulan Februari sampai Oktober 2021. Penelitian terdiri dari beberapa tahapan, yaitu 1) Perbanyakan propagul Nigrospora sp., 2) penyiapan suspensi P. oryzae, 3) uji penghambatan pertumbuhan P.oryzae pada tanaman padi. Sebagai pembanding digunakan tanaman yang diberi perlakuan fungisida berbahan aktif trisiklazol dan tanaman kontrol yang tidak diberi perlakuan. Pengamatan yang dilakukan meliputi intensitas penyakit, kolonisasi cendawan endofit pada potongan daun, dan parameter pertumbuhan tanaman padi. Meskipun kejadian penyakit mencapai 100 % untuk semua perlakuan pada pengamatan terakhir (7 minggu setelah inokulasi), namun demikian tingkat keparahannya tertekan oleh perlakuan Nigrospora. Cendawan endofit Nigrospora sp. mampu menekan keparahan penyakit blas daun sebesar 28-32 % dan blas leher sebesar 20-30% jika dibandingkan dengan kontrol. Penekanan penyakit blas paling stabil mulai dari awal pengamatan sampai akhir pengamatan ditunjukkan oleh perlakuan perendaman benih + penyemprotan Nigrospora sp. Kemampuan cendawan endofit dalam mengolonisasi tanaman padi pada perlakuan Nigrospora sp. berkisar antara 40-55%. Selain dapat menekan pertumbuhan penyakit blas, perlakuan cendawan endofit Nigrospora sp. juga menunjukkan pengaruh positif terhadap parameter pertumbuhan tanaman, antara lain tinggi tajuk, jumlah anakan dan jumlah anakan produktif, bobot gabah basah dan bobot gabah kering.

Blast disease (Pyricularia oryzae) is a disease that attacks rice plants which can cause losses of 1-50% in the world. Blast disease control using resistant varieties and the use of fungicides are still considered ineffective due to the high genenetic variability of the pathogen. Biological control is expected to be one of the alternative control measures, one of which is using endophytic fungi. This study aims to determine the potential of the endophytic fungus Nigrospora sp. in suppressing blast disease caused by P. oryzae. The research was carried out at CV. WiSH Indonesia from February to October 2021. The study consisted of some activities, including propagule reproduction of Nigrospora sp., preparation of P.oryzae conidial suspension, and in planta test of the ability of Nigrospora sp. in blast disease suppression. As comparison treatments, plants were treated with fungicides (active ingredient tricyclazole) and control plants without any treatments. Observations were also made on the endophytic fungal colonization test as well as the rice plant growth parameters. Even though the incidence of the disease reached 100% for all treatments at the last observation (7 weeks after inoculation), however the severity was suppressed by the Nigrospora treatment. The endophytic fungus Nigrospora sp. was able to reduce the severity of leaf blast disease by 28 -32% and neck blast by 20-30% when compared to controls. The most stable suppression of blast disease from the beginning of the observation to the end of the observation was indicated by seed treatment + spraying treatment of Nigrospora sp. The ability of endophytic fungi to colonize rice plants in the treatment of Nigrospora sp. ranged from 40-55%. Besides being able to suppress the growth of blast disease, the treatment of the endophytic fungus Nigrospora sp. also showed a positive effect on plant growth parameters, includingshoot height, number of tillers and number of productive tillers, wet and dry wight of harvested grain.