Keragaman dan Patogenesitas Colletotrichum Asal Tanaman Hortikultura dan Perkebunan Penting di Indonesia.

Abstract

Spesies Colletotrichum yang patogenik telah diteliti secara luas sebagai agen penyebab penyakit antraknosa terutama pada tanaman hortikultura, perkebunan, dan tanaman pangan. Kajian tentang identifikasi spesies Colletotrichum pada tanaman hortikultura dan perkebunan penting di Indonesia masih sangat jarang, dan belum menggunakan metode terkini. Penggunaan gabungan metode diagnostik karakter morfologi, molekuler dengan analisis multilokus gen, dan patogenesitas merupakan pendekatan yang tepat untuk mengidentifikasi Colletotrichum kompleks spesies. Penelitian ini bertujuan untuk mengkarakterisasi keragaman morfologi, molekuler, dan patogenesitas Colletotrichum asal tanaman hortikultura dan perkebunan penting di Indonesia. Spesies Colletotrichum diisolasi dari 14 jenis tanaman hortikultura asal Indonesia, buah jeruk impor asal Cina dan Pakistan, dan 11 klon tanaman karet asal Sumatera Selatan, Indonesia. Isolat Colletotrichum diidentifikasi karakter morfologi, molekuler, dan patogenesitasnya pada tanaman cabai, karet, dan kakao. Identifikasi secara molekuler menggunakan analisis multilokus gen menggunakan penanda gen ITS, ACT, GAPDH, dan TUB2. Patogenesitas isolat diuji pada tanaman cabai, karet, dan kakao dengan metode inokulasi pelukaan daun atau buah, dan tanpa pelukaan. Hasil penelitian menunjukkan pada tanaman hortikultura ditemukan 11 spesies Colletotrichum yaitu C. gloeosporioides sensu stricto, C. endophyticum, C. siamense, C. asianum, C. musae, C. queenslandicum, C. truncatum, C. okinawense, C. nymphaeae, C. paxtonii, dan C. scovillei. Pada penelitian ini diperoleh data terbaru kisaran inang spesies Colletotrichum asal tanaman hortikultura yang diketahui bersifat kosmopolit (memiliki banyak inang) maupun spesifik inang. Spesies kosmopolit seperti C. gloeosporioides s.s menginfeksi jeruk, cabai, karet, dan kakao. Spesies lainnya yaitu C. siamense menginfeksi buah naga, apel, srikaya, karet, dan kakao, sedangkan C. asianum menginfeksi buah alpukat, mangga, cabai, karet, dan kakao. Spesies kosmopolit lainnya yaitu C. truncatum menginfeksi timun suri, tomat, kabocha, buah naga, cabai, karet, dan kakao. Didapatkan data terbaru bahwa C. paxtonii menginfeksi apel, cabai dan karet. Temuan lainnya yaitu C. endophyticum menginfeksi jambu biji dan karet, sedangkan C. queenslandicum menginfeksi jambu mete dan karet. Dua spesies diketahui bersifat spesifik inang yaitu C. musae hanya menginfeksi buah pisang, sedangkan C. okinawense hanya menginfeksi buah papaya. Penelitian pada buah jeruk impor asal Cina dan Pakistan ditemukan 4 spesies Colletotrichum yaitu C. fructicola, C. karstii, C. gloeosporioides s.s, C. siamense, sedangkan pada buah jeruk Indonesia teridentifikasi satu spesies yaitu C. gloeosporioides s.s. Seluruh isolat asal jeruk impor dan asal Indonesia dapat menginfeksi buah cabai, namun hanya C. siamense asal Pakistan dan C. gloeosporioides s.s asal Indonesia yang mampu menginfeksi daun karet. Isolat asal jeruk impor dan lokal mampu menginfeksi daun kakao kecuali C. fructicola asal Cina. Penelitian spesies Colletotrichum pada tanaman karet di Indonesia menghasilkan 2 spesies C. acutatum kompleks spesies yaitu C. wanningense, dan C. cairnsense. Temuan kedua spesies tersebut merupakan laporan pertama spesies Colletotrichum penyebab penyakit antraknosa pada tanaman karet di Indonesia, yang telah diidentifikasi molekuler secara multilokus gen. Isolat C. wanningense dan C. cairnsense berbeda patogenesitasnya pada tanaman karet, namun keduanya tidak patogenik terhadap cabai. Penelitian ini menghasilkan data status terkini spesies Colletotrichum yang menginfeksi tanaman hortikultura Indonesia, buah jeruk asal impor, serta tanaman karet dan kakao di Indonesia. Pengetahuan ini diharapkan dapat bermanfaat dalam upaya pengendalian penyakit yang efektif di lapangan, dan tindakan perkarantinaan tumbuhan di Indonesia.

Pathogenic Colletotrichum species have been widely studied as causative agents of anthracnose, especially in horticultural, plantation and food crops. Studies on the identification of Colletotrichum species in important horticultural and plantation crops in Indonesia are still very rare, and do not use the latest methods. The combined use of diagnostic methods of morphological, molecular characters with multilocus gene analysis, and pathogenicity is an appropriate approach to identify the Colletotrichum species complex. This research aims to characterize the morphological, molecular and pathogenicity diversity of Colletotrichum from important horticultural and plantation crops in Indonesia. Colletotrichum species were isolated from 14 types of horticultural plants from Indonesia, imported citrus fruit from China and Pakistan, and 11 clones of rubber plants from South Sumatra, Indonesia. Colletotrichum isolates were identified for their morphological, molecular and pathogenicity characteristics on chili, rubber and cocoa plants. Molecular identification using multilocus gene analysis using ITS, ACT, GAPDH, and TUB2 gene markers. The pathogenicity of the isolates was tested on chili, rubber and cocoa plants using the leaf or fruit wound inoculation method, and without wounding. The results of the research showed that in horticultural plants 11 species of Colletotrichum were found, namely C. gloeosporioides sensu stricto, C. endophyticum, C. siamense, C. asianum, C. musae, C. queenslandicum, C. truncatum, C. okinawense, C. nymphaeae, C. . paxtonii, and C. scovillei. In this study, the latest data was obtained on the host range of Colletotrichum species from horticultural plants which are known to be cosmopolitan (have many hosts) or host specific. Cosmopolitan species such as C. gloeosporioides s.s infect citrus, chilies, rubber and cocoa. Another species, namely C. siamense, infects dragon fruit, apples, sugar apples, rubber and cocoa, while C. asianum infects avocados, mangoes, chilies, rubber and cocoa. Another cosmopolitan species, C. truncatum, infects suri cucumber, tomato, kabocha, dragon fruit, chili, rubber and cocoa. The latest data shows that C. paxtonii infects apples, chilies and rubber. Another finding is that C. endophyticum infects guava and rubber, while C. queenslandicum infects cashew apple and rubber. Two species are known to be host specific, namely C. musae only infects bananas, while C. okinawense only infects papaya. Research on imported citrus fruit from China and Pakistan found 4 species of Colletotrichum, namely C. fructicola, C. karstii, C. gloeosporioides s.s, C. siamense, while in Indonesian citrus fruit one species was identified, namely C. gloeosporioides s.s. All isolates from imported oranges and from Indonesia can infect chili fruit, but only C. siamense from Pakistan and C. gloeosporioides s.s from Indonesia are able to infect rubber leaves. Imported and local citrus isolates were able to infect cocoa leaves, except for C. fructicola from China. Research on Colletotrichum species on rubber plants in Indonesia produced 2 species of the C. acutatum species complex, namely C. wanningense and C. cairnsense. The discovery of these two species is the first report of the Colletotrichum species causing anthracnose disease in rubber plants in Indonesia, which has been identified molecularly using multi-gene loci. C. wanningense and C. cairnsense isolates differ in their pathogenicity on rubber plants, but both are not pathogenic on chilies. This research produces data on the current status of the Colletotrichum species which infects Indonesian horticultural plants, imported citrus fruit, as well as rubber and cocoa plants in Indonesia. It is hoped that this knowledge will be useful in effective disease control efforts in the field and plant quarantine measures in Indonesia.