KARAKTER MORFOLOGI DAN MOLEKULER ISOLAT Phytophthora palmivora ASAL KELAPA DAN KAKAO
Authors: MOTULO HIASINTA FJ , S-SINAGA MEITY , SUASTIKA GEDE , ASWIDINNOOR HAJRIAL , HARTANA ALEX 
Published: June 2020

ABSTRAK<br />Phytophthora palmivora merupakan patogen penyebab penyakit<br />gugur buah pada tanaman kelapa dan busuk buah pada tanaman kakao.<br />Penelitian ini bertujuan untuk membedakan isolat P. palmivora asal kelapa<br />dan asal kakao berdasarkan karakter morfologi dan molekuler.<br />Pengambilan sampel penyakit gugur buah kelapa dan busuk buah kakao<br />dilakukan di Kabupaten Banyuwangi dan Jember, Jawa Timur, Kabupaten<br />Minahasa dan Bolaang Mongondow, Sulawesi Utara, dan Kabupaten<br />Gorontalo, Gorontalo. Analisis morfologi, ekstraksi DNA dan amplifikasi<br />DNA dengan PCR dilakukan di Laboratorium Mikologi dan Laboratorium<br />Virologi, Departemen Proteksi Tanaman, Faperta IPB. Analisis perunutan<br />DNA dilakukan di Laboratorium Biologi Molekuler, Balai Besar<br />Bioteknologi dan Sumberdaya Genetik dan Laboratorium Bioteknologi,<br />LIPI Serpong. Penelitian dilaksanakan pada bulan April 2005 sampai<br />Februari 2007. Berdasarkan karakter morfologi seperti diameter koloni,<br />panjang dan lebar sporangium, tipe koloni, bentuk sporangium, per-<br />bandingan panjang dan lebar sporangium serta runutan DNA ruas ITS<br />menunjukkan bahwa keduapuluh-dua koleksi isolat yang menunjukkan<br />gejala penyakit gugur buah kelapa dan busuk buah kakao adalah P.<br />palmivora. Isolat P. palmivora asal kelapa berbeda dengan isolat P.<br />palmivora asal kakao berdasarkan diameter koloni, panjang dan lebar<br />sporangium serta runutan DNA ruas ITS. Duapuluh-dua isolat P.<br />palmivora asal kelapa dan asal kakao mempunyai sporangium yang mudah<br />lepas dari sporangiospora (caducous), pedikel yang pendek dan papila<br />serta bervariasi dalam bentuk dan ukuran sporangium. Bentuk sporangium<br />terdiri dari 4 tipe yaitu ovoid, limoniform, obturbinate, dan obpyriform.<br />Ukuran sporangium berkisar antara 40 – 62 µm panjang dan 28 – 43 µm<br />lebar. Isolat P. palmivora memiliki tipe koloni rosaceous, stelate dan<br />cottony. Rata-rata diameter koloni isolat asal kelapa 54.8 cm lebih tinggi<br />dari isolat asal kakao 43,4 cm. Hasil perunutan DNA hasil PCR<br />menunjukkan adanya keragaman genetik antar isolat asal kelapa dan kakao<br />di Indonesia. Isolat asal kakao berbeda dengan isolat asal kelapa<br />berdasarkan perunutan DNA ruas ITS. Isolat P. palmivora asal kelapa dan<br />kakao dari Indonesia tidak berada dalam satu kelompok dengan isolat<br />yang berasal dari Thailand, Taiwan, Korea, Puerto Rico, Ghana, dan<br />Cameron.<br />Kata kunci : Kelapa, Cocos nucifera, kakao, Theobroma cacao, penyakit,<br />P. palmivora, morfologi, molekuler, keragaman, runutan<br />DNA-ITS, Jawa Timur, Sulawesi Utara, Gorontalo, Jawa<br />Barat<br />ABSTRACT<br />Morphology and molecular characteristics of P.<br />palmivora isolates from coconut and cacao<br />Phytophthora palmivora, is the pathogen of coconut nutfall and<br />cacao black pod diseases. This study was conducted to differentiate the<br />isolates of P. palmivora from coconut and those from cacao fruit based on<br />morphology and molecular characteristics. Samples of nutfall of coconut<br />and black pod of cacao were collected from Banyuwangi and Jember<br />Districts, East Java, Minahasa and Bolaang Mongondow Districts, North<br />Sulawesi, and Gorontalo District, Gorontalo. Morphological analysis,<br />DNA extraction and amplification of PCR-DNA were conducted in<br />Micology Laboratorium and Virology Laboratorium, Plant Protection<br />Division, Faperta IPB. Sequencing DNA analysis was conducted in<br />Molecular Biology Laboratory, Balai Besar Bioteknologi dan Sumberdaya<br />Genetik and Biotechnology Laboratory LIPI Serpong. This research was<br />conducted from April 2005 to February 2007. Comparative morphological<br />evaluated i.e. diameter of colony, length and width of sporangium, l/w<br />ratio, type of colony and sequence Internal Transcribed Sequence (ITS)-<br />DNA showed that all isolates of Phytophthora isolated from coconut and<br />cacao in Indonesia were Phytophthora palmivora. Morphology<br />characteristics of pathogen isolates from cacao were smaller and<br />significantly different in length, width, length/width ratio of<br />sporangium and diameter of colony compared to coconut’s isolates.<br />Sporangia of 22 isolates were caducous with short pedicel, but were<br />variable in shape and size. The culture produced ovoid, limoniform,<br />obturbinate, dan obpyriform sporangia, average 40-62 µm in length and<br />28-43 µm in width. The colony types were stelate, cottony and rossaceous<br />with average diameter of coconut isolates 54.8 cm and cacao isolates 43.4<br />cm. Specific fragment of 900 bp was successfully amplify from coconut<br />and cacao infected by P. palmivora. The DNA sequence analysis of the<br />nuclear ribosomal internal transcribed spacer (ITS) region showed that the<br />coconut isolates were not in the same cluster with the cacao isolates. Based<br />on sequence analysis, the P. palmivora isolates from Indonesia showed<br />different cluster from those of Taiwan, Ghana, Puerto Rico and Costa Rica<br />isolates.<br />Key words : Coconut, Cocos nucifera, cacao, Theobroma cacao,<br />diseases, P. palmivora, diversity, morphology, molecular,<br />sequencing ITS-DNA, East Java, North Sulawesi,<br />Gorontalo, West Jav