<p>ABSTRAK<br />Benih merupakan komponen dasar dalam menentukan produktivitas<br />tanaman kakao. Benih yang sehat dapat merupakan faktor penting dalam<br />menentukan keberhasilan produktivitas kakao. Benih kakao mempunyai<br />kadar air cukup tinggi sehingga berpotensi terinfeksi cendawan, yang<br />dapat menurunkan mutu benih dan produksi kakao. Penelitian bertujuan<br />untuk mengisolasi dan mengidentifikasi beberapa cendawan terbawa benih<br />pada kakao hibrida. Penelitian dilakukan di Kebun Induk Benih Pusat<br />Penelitian Kopi dan Kakao Indonesia, Jember, Laboratorium Mikro-<br />biologi, Balai Penelitian Bioteknologi Perkebunan Indonesia, dan<br />Laboratorium Pengendalian Hayati IPB Bogor pada bulan Juni sampai<br />Oktober 2008. Penelitian menggunakan benih kakao hibrida dari hasil<br />persilangan buatan antar TSH 858 dengan Sca 6, dan percobaan disusun<br />dengan rancangan acak lengkap dengan 3 ulangan. Benih ditumbuhkan<br />pada 3 media, yaitu water agar (WA), potato dextrose agar (PDA), dan<br />kertas saring (KS). Tingkat infeksi pada benih diamati setiap hari dan<br />dianalisis dengan analisis sidik ragam dan dilanjutkan dengan uji selang<br />berganda Duncan. Cendawan diisolasi, dibiakkan, dimurnikan, dan<br />diidentifikasi dengan menggunakan buku kunci identifikasi. Tingkat<br />infeksi cendawan terbawa benih kakao hibrida tertinggi terdapat pada hari<br />keempat (35,00%) dan kelima (51,67%) pada media PDA. Sebanyak 13<br />spesies cendawan terbawa benih kakao hibrida berhasil diidentifikasi<br />dengan menggunakan media WA dan PDA, serta 8 spesies cendawan<br />dengan media KS. Ke-13 cendawan terbawa benih yang ditemukan sangat<br />berpotensi menurunkan mutu fisiologis benih dan produktivitas kakao.<br />Cendawan tersebut perlu diuji lebih lanjut karena masing-masing memiliki<br />sifat-sifat patogenik, saprofitik, atau antagonistis terhadap cendawan lain<br />pada benih kakao. Cendawan terbawa benih kakao hibrida paling dominan<br />adalah Aspergillus spp., Penicillium chrysogenium, Coletotrichum<br />acutatum, Curvularia geniculata, dan Fusarium spp. Cendawan-cendawan<br />yang diduga berbahaya adalah Aspergillus spp., Coletotrichum acutatum,<br />Curvularia geniculata, Fusarium spp., Phoma glomerata, dan<br />Macrophoma sp., dan yang diduga bersifat patogenik adalah Aspergillus<br />flavus, Aspergillus ochraceus, Cladosporium herbanum, Curvularia<br />geniculata, Fusarium oxysporum, Phoma glomerata, dan Macrophoma sp.</p><p>Kata kunci : Theobroma cacao, benih hibrida, infeksi cendawan, media<br />tanam</p><p>Isolation and Identification of Fungi on Hybrid Cacao Seeds</p><p>ABSTRACT<br />Seed is the basic component influencing the productivity of cacao<br />plantation. Healthy seed is the most important factor in determining the<br />success of cacao productivity. Moisture content of cacao seeds is quite<br />high potentially to cause fungi infection, which can further reduce seed<br />quality and cacao production. The research aimed at isolating and<br />identifying several seedborne fungi on hybrid cacao. The study was<br />conducted at main nursery of Indonesian Coffee and Cocoa Research<br />Institute Jember, Laboratory of Microbiology, Indonesian Biotechnology<br />Research Institute for Estate Crops, and the Laboratory for Biological<br />Control of IPB Bogor from June to October 2008. Research used hybrid<br />cacao seeds derived from crossing between TSH 858 x SCA 6, and the<br />experiment was arranged using completely randomized design with three<br />replicates. Cacao seeds were grown on three media, i.e. water agar (WA),<br />potato dextrose agar (PDA), and filter paper (KS). Infection rates on the<br />seedlings were observed every day and analyzed using ANOVA followed<br />by Duncan's multiple regression test (DMRT). Fungi were isolated,<br />cultured, purified, and identified using the identification keys. The highest<br />rate of seedborn fungal infection occured on fourth (35.00%) and fifth<br />(51.67%) days on PDA media. A total of 13 species of seedborn fungi on<br />hybrid cocoa were identified by using WA and PDA media, as well as 8<br />other species by using KS. The 13 seedborne fungi potentially reduce seed<br />physiological quality and cacao productivity. These fungi need to be<br />further tested because each has its own pathogenic, saprophytic, or<br />antagonistic properties towards other fungi on cacao seeds. Predominant<br />seedborn fungi on hybrid cacao were Aspergillus spp., Penicillium<br />chrysogenium, Coletotrichum acutatum, Curvularia geniculata, and<br />Fusarium spp. The fungi suspected harmful were Aspergillus spp.,<br />Coletotrichum acutatum, Curvularia geniculata, Fusarium spp., Phoma<br />glomerata, and Macrophoma sp., and those suspected pathogenic were<br />Aspergillus flavus, Aspergillus ochraceus, Cladosporium herbanum,<br />Curvularia geniculata, Fusarium oxysporum, Phoma glomerata, and<br />Macrophoma sp.<br />Key words : Theobroma cacao, fungi infection, hybrid seed, growing<br />media</p>
Isolation and Identification of Fungi Associated with the Spoilage of Sweet Orange and Banana in Sokoto Metropolis
