Evaluasi Resistensi dan Daya Hasil Enam Klon Harapan Kentang Transgenik Terhadap Serangan Penyakit Hawar Daun (Evaluation of Resistance to Late Blight and Tuber Yield of Six Potential Potato Transgenic Clones)

Penyakit hawar daun (Phytophthora infestans) merupakan salah satu penyakit utama pada tanaman kentang. Kerusakan yang berat akibat penyakit hawar daun dapat menyebabkan kehilangan hasil panen sampai 80%. Gen pembawa ketahanan terhadap penyakit hawar daun dikenal dengan nama gen RB dan telah berhasil dimasukkan ke dalam genom kentang dan menghasilkan kentang transgenik. Tujuan penelitian untuk menguji ketahanan enam klon kentang transgenik terhadap serangan penyakit hawar daun (P. infestans) dan daya hasil. Penelitian dilakukan di Lapangan Uji Terbatas Desa Citere, Kecamatan Pangalengan, Kabupaten Bandung, 1.400 m di atas permukaan laut. Rancangan percobaan menggunakan rancangan petak terpisah, dengan petak utama perlakuan tidak disemprot fungisida dan disemprot fungisida dua kali seminggu dan anak petak 10 genotipe kentang yang terdiri atas enam hibrida kentang transgenik, satu genotipe kentang transgenik Katahdin SP951 sebagai pembanding resisten dan tiga varietas pembanding rentan kentang nontransgenik Granola, Atlantic, dan Katahdin. Jumlah ulangan tiga kali dengan populasi tanaman terdiri atas 50 tanaman/plot. Pengamatan dilakukan terhadap vigor tanaman, insiden serangan hawar daun, dan komponen hasil. Hasil pengamatan menunjukkan bahwa untuk vigor tanaman tidak terjadi interaksi serta antarperlakuan tidak berbeda nyata. Genotipe yang resisten terhadap hawar daun adalah klon 20, 27, 65, dan 66 setara dengan kontrol positif Katahdin SP951 dan nyata lebih resisten dari varietas pembanding Granola, Atlantic, dan Katahdin. Klon yang resisten terhadap hawar daun menampilkan hasil yang tinggi pada plot tidak disemprot fungisida, sementara pada plot disemprot fungisida 20 kali semua genotipe menampilkan hasil optimalnya. Tingkat kehilangan hasil mencapai 18,8–84,4%. Genotipe dengan intensitas serangan hawar daun tinggi memiliki tingkat kehilangan hasil yang juga tinggi. Klon 20 dan 27 menampilkan daya hasil yang relatif tinggi dengan penundaan penggunaan fungisida 7 minggu setelah tanam.KeywordsGenotipe; P. infestans; Solanum tuberosum LAbstractLate blight (Phytophthora infestans) is one of main potato diseases. Due to severe damage to late blight potato, crop will be cause lost of harvest up to 80%. Gene carriers of resistance to late blight known as the RB gene and have been incorporate into the genom of potato and produce transgenic potato. The objective of the research was to test six advanced transgenic potato clones for resistance to late blight (Phytophthora infestans). The research was conducted at Confined Field Trial at Citere Village, Pangalengan District Bandung (1,400 m above sea level). The experimental design was split plot. The main plot was spray with fungicides twice/week and was replicated three times. Subplot were 10 potato genotypes, consists of six transgenic potato hybrids, transgenic Katahdin SP951 as resistant check and three varieties of nontransgenic as susceptible check, i.e. Granola, Atlantic, and Katahdin.  An experimental unit consists of 50 plants/plot, every treatment with three replicates. Plant observed were plant vigor, intensity of late blight damage, tuber yield component, and lost of yield. The result showed that there were no interaction of plant vigor and also all the treatmens were not significantly different. Transgenic potato clones of 20, 27, 65, 66, and Katahdin SP951 were resistant to late blight compare to check varieties of Granola, Atlantic, and Katahdin. The highest yielding at none spraying of fungicides were obtained from the resistance clones. Whereas,  on the 20 sprayed fungicides all of  the clones were high yielding. Tuber yield lossed ranged from 18,8–84,4%, the susceptible genotypes were also showed high losses. Clones 20 and 27 showed reletive high yielding and can be delayed application fungicides for period of 7 weeks after planting.