BIODIVERSITAS BAKTERI TANAH PEMARASIT NEMATODA SISTA KUNING (GLOBODERA ROSTOCHIENSIS)

Irianti Kurniasari, Dr. Ir. Jaka Widada, M.P

2012 | Tesis | S2 Bioteknologi

Nematoda sista kuning (Globodera rostochiensis) dilaporkan keberadaanya pertama kali di Indonesia pada tahun 2003, dan saat ini menjadi hama penting pada tanaman kentang. Bakteri tanah pemarasit sista ditemukan hanya memarasit nematoda dari genus Globodera sp. Penelitian ini bertujuan untuk mengetahui keberadaan dan keragaman bakteri tanah pemarasit G. rostochiensis. Isolasi bakteri tanah pemarasit G. rostochiensis dilakukan dari tanah yang diambil pada daerah perakaran tanaman kentang terserang dan tidak terserang G. rostochiensisdi 6 lokasi yang berbeda di Kabupaten Wonosobo dan Banjarnegara. Medium yang digunakan untuk menumbuhkan isolat bakteri yaitu medium nutrien dan ekstrak tanah agar. Uji kemampuan parasitasi isolat bakteri dilakukan terhadap sista dan telur nematoda sista kuning G. rostochiensis. Biodiversitas isolat bakteri tanah pemarasit G. rostochiensis ditentukan dengan menganalisis keragaman genetik menggunakan PCR TP-RAPD dan UPGMA. Diperoleh 45 isolat bakteri tanah pemarasit G. rostochiensis, dengan jumlah isolat yang berasal dari daerah perakaran tanaman kentang terserang dan tidak terserang G. rostochiensis sebanyak 24 dan 21 isolat. Persentase tertinggi kemampuan parasitasi terhadap sista dan telur berturut-turut sebesar 80% dan 98,7%. Hasil analisis keragaman genetik diperoleh bahwa 33 isolat mempunyai nilai indeks similaritas kurang dari 97%, dan 12 isolat memiliki nilai indeks similaritas lebih dari 97%, sehingga 73,3% isolat bakteri tanah pemarasit G. rostochiensis berbeda. Kesimpulan dari penelitian ini yaitu bakteri tanah pemarasit G. rostochiensis telah ada dan beragam di tanah pertanaman kentang.

Golden potato cyst nematode, Globodera rostochiensis, was firstly reported to be detected in Indonesia for the first time in 2003 and currently is being an important potato pest. The parasitic soil bacteria found only parasitic on cyst nematode of the genera Globodera, but not specifically on the species G. rostochiensis. This research is conducted to find out the existence and diversity of parasitic soil bacteria against G. rostochiensis. Soils taken from rhizospheric healthy and infected potato plant were used for bacterial isolation. Nutrient and soil extracts agar media used to grow the bacterial isolates. The parasitic ability of bacterial isolates were tested against cysts and eggs ofG. rostochiensis using bioassay method. The genetic diversity of the isolates was determined using PCR TP-RAPD (Polymerase Chain Reactions Two Primer Random Amplified Polymorphic DNA) technique and UPGMA (Unweighted Pair Group Method Arithmetic Average). Fourty five isolates were observed to be parasitic against cysts and eggs of G. rostochiensis. Among them, 24 and 21 isolates were from healthy and infected potato plant rhizosphere soils, respectively. Eighty and ninety eight point seven percent of total cysts and eggs, respectively, could be parasitized by the best isolate. The genetic diversity analysis showed that 33 isolates have similarity index value less than 97% and 12 isolates have similarity index value more than 97%, indicated that 73,3% of the isolates are different. It can be concluded, that the soil bacteria which are parasitic to G. rostochiensis has been evolved, as well as their diversity.

Kata Kunci : biodiversitas, bakteri parasit, parasit telur dan sista, nematoda sista kuning, Globodera rostochiensis