Potensi Binukleat Rhizoctonia (BNR) Sebagai Agen Biokontrol Penyakit Bercak Daun (Cercospora personata (Berk. & M.A.Curtis) Ellis.) Pada Tanaman Kacang Tanah (Arachis hypogaea L.)
Yuana Nindi Astisa, Rina Sri Kasiamdari, S.Si., Ph.D.
2023 | Skripsi | BIOLOGI
Kacang tanah (Arachis hypogaea L.) merupakan komoditas pangan yang banyak dibudidayakan di Indonesia karena memiliki nilai ekonomi yang tinggi serta kandungan nutrisi yang dapat dijadikan sebagai sumber protein dan minyak nabati. Serangan C.personata menyebabkan kacang tanah terserang penyakit bercak daun dan berdampak pada penurunan hasil panen baik secara kualitas maupun kuantitas. Dalam rangka mengurangi dampak penggunaan fungisida, digunakannya agen biokontrol yang lebih ramah lingkungan merupakan langkah yang tepat untuk mengendalikan serangan C.personata. Penggunaan jamur Binukleat Rhizoctonia dilaporkan efektif dalam mengendalikan laju pertumbuhan jamur patogen seperti R. solani, Pythium spp., Phytophthora spp., dan Fusarium spp. pada tanaman mentimun. Penelitian ini perlu dilakukan untuk mengetahui potensi BNR sebagai agen biokontrol penyakit bercak daun akibat serangan C.personata pada tanaman kacang tanah. Metode yang dilakukan dalam penelitian ini yaitu diantaranya: isolasi dan identifikasi jamur C.personata dari daun kacang tanah yang bergejala bercak daun serta tiga isolat BNR meliputi Ceratorhiza sp., Sistotrema sp., dan Ceratobasidium sp. dari perakaran anggrek Phalaenopsis amabilis dan Dendrobium lineale, uji Postulat Koch, uji daya hambat isolat BNR terhadap C.personata secara in vitro, serta uji efektivitas BNR sebagai agen biokontrol C.personata pada semai tanaman kacang tanah. Hasil penelitian menunjukkan bahwa C.personata memiliki hifa bersekat dan bercabang serta konidia yang pendek, sedikit melengkung, berisi, dan bersekat. BNR memiliki hifa berinti dua, berwarna hialin, sudut percabangan hifa 90o, dan masing-masing memiliki sel monilioid yang berbeda. Ceratorhiza sp. memiliki sel monilioid berbentuk elongate barrel shape, Sistotrema sp. memiliki sel monilioid berbentuk clavate pada ujung hifa, serta Ceratobasidium sp. tidak memilliki sel monilioid. Hasil uji daya hambat secara in vitro pada hari ketujuh menunjukkan bahwa Sistotrema sp. memiliki persentase penghambatan tertinggi yaitu 54,25%, dan Ceratorhiza sp. sebesar 51,62% serta Ceratobasidium sp. sebesar 49,04%. Hasil uji efektivitas secara in vivo pada minggu ketujuh menunjukkan bahwa inokulasi Sistotrema sp. paling efektif dalam menurunkan intensitas penyakit hingga sebesar 89,8%, dan Ceratorhiza sp. sebesar 86,4% serta Ceratobasidium sp. sebesar 77,9%. Inokulasi Sistotrema sp. terbukti pada minggu ketujuh dapat meningkatkan tinggi tanaman sebesar 23,76% serta jumlah daun sehat sebesar 52,64%; Ceratorhiza sp. meningkatkan tinggi tanaman sebesar 15,94% serta jumlah daun sehat sebesar 34,58%; dan Ceratobasidium sp. meningkatkan tinggi tanaman sebesar 14,70% serta jumlah daun sehat sebesar 28,66%.
Groundnut (Arachis hypogaea L.) is a food commodity that is widely cultivated in Indonesia because it has high economic value and nutritional content that can be used as a source of protein and vegetable oil. C.personata caused peanuts to develop leaf spot disease and has impact on decreasing crop yields both in quality and quantity. In order to reduce the impact of the use of fungicides, the use of biocontrol agents that are more environmentally friendly is the right step to control C.personata. The use of Binucleate Rhizoctonia was reported to be effective in controlling the growth rate of pathogenic jamur such as R. solani, Pythium spp., Phytophthora spp., and Fusarium spp. on cucumber plants. This research needs to be conducted to determine the potential of BNR as a biocontrol agent for leaf spot disease caused by C.personata on groudnut plants. This research was conducted to isolate and identify C.personata from groundnut leaves with leaf spot sysptoms and three BNR isolates were identified as Ceratorhiza sp., Sistotrema sp., and Ceratobasidium sp. from the roots of Phalaenopsis amabilis and Dendrobium liniale, the Koch Postulates test, test of the inhibition of BNR isolates against C.personata in vitro, and test the effectiveness of BNR as a biocontrol agent for C.personata in groundnut seedling. The results showed that C.personata had septed and branched hyphae and conidia were short, slightly curved, filled and insulated. BNR has hyphae binuclear, hyaline colored, hyphal branching angle of 90o, and each has a different monilioid cell. Ceratorhiza sp. has elongate barrel-shaped monilioid cells, Sistotrema sp. has clavate-shaped monilioid cells at the end of the hyphae, as well as Ceratobasidium sp. do not have monilioid cells. The results of the in vitro inhibition test on the seventh day showed that Sistotrema sp. had the highest inhibition percentage of 54.25%, and Ceratorhiza sp. of 51.62% and Ceratobasidium sp. of 49.04%. The results of the in vivo effectiveness test in the seventh week showed that the inoculation of Sistotrema sp. most effective in reducing disease intensity by 89.8%, and Ceratorhiza sp. of 86.4% and Ceratobasidium sp. of 77.9%. Inoculation of Sistotrema sp. proven in the seventh week to increase plant height by 23.76% and the number of healthy leaves by 52.64%; Ceratorhiza sp. increased plant height by 15.94% and the number of healthy leaves by 34.58%; and Ceratobasidium sp. increased plant height by 14.70% and the number of healthy leaves by 28.66%.
Kata Kunci : bercak, biokontrol, binukleat, daun, kacang
