Evaluasi Produktivitas Padi Transgenik Rojolele yang Potensial Tahan Penggerek Batang Padi Kuning Scirpophaga incertulas Wlk

Rice yellow stem borer (YSB, Scirpophaga incertulas Wlk) is one of the most damaging rice pests in Indonesia, especially in rice growing centers in West Java. Because there is no source of resistance genes in rice or its close relatives, resistant improvement by genetic engineering is one strategy to obtain resistant rice cultivar. Previously, the cryIB::cryIAa fusion gene from Bacillus thuringiensis has been introduced into the Rojolele variety to obtain 6 transgenic rice events resistant to YSB (X22, U10, W3, Y7, Q20, and P8) and has been tested for resistance in greenhouses. This study was aimed to evaluate the transgenic rice productivity carried out in a confined field trial in field station belonging to the Center for Rice Research in Sukamandi, Subang, West Java. The procedure for the field testing followed the 1998 Guidelines for Biosafety Testing of Agricultural Biotechnology Products: Plant Seri by the Ministry of Agriculture. The parameters observed were agronomic characters (plant height, number of tillers, and number of panicles) and yield components (number of filled grains per panicle, number of empty grains per panicle, panicle length, and weight of 1000 grains). The yield was also measured by dry grain yield. The results indicated that the performance were varied among the 6 events tested. Rice events X22, W3, Y7, and P8 showed agronomic characteristics and yield components resembled Rojolele varieties, and performed well under field condition. X22 and W3 showed closest resemblance to Rojolele in terms of yield potential. Keywords: confined field trial, cryIB::cryIAa, production, rice yellow stem borrer, rojolele rice, transgenic

Pengujian Ketahanan Klon-klon Hasil Silangan Tanaman Kentang Transgenik dengan Nontransgenik terhadap Penyakit Hawar Daun Phytophthora infestans di Lapangan Uji Terbatas

STRAK. Tanaman kentang transgenik Katahdin event SP904 dan SP951 mengandung gen RB, yang diisolasi dari spesies liar kentang diploid Solanum bulbocastanum. Gen RB mempunyai ketahanan yang bersifat durable dengan spektrum yang luas terhadap ras-ras Phytophthora infestans di Amerika Serikat. Dalam perakitan tanaman kentang tahan penyakit hawar daun P. infestans di Indonesia, transgenik Katahdin dijadikan sebagai donor tahan dalam persilangan dengan varietas rentan Atlantik dan Granola. Klon-klon hasil silangan dianalisis secara molekuler mengandung gen RB. Penelitian dilakukan untuk menguji ketahanan klon-klon hasil silangan tanaman kentang transgenik dengan nontransgenik terhadap isolat P. infestans di lapangan uji terbatas (LUT) yang berlokasi di Balai Penelitian Tanaman Sayuran (Balitsa), Lembang dari bulan Oktober 2009 sampai dengan Maret 2010. Klon-klon yang diuji ialah 12 klon hasil silangan Atlantik x transgenik Katahdin SP904 (A); 15 klon hasil silangan Atlantik x transgenik Katahdin SP951 (B); 17 klon hasil silangan Granola x transgenik Katahdin SP904 (C); dan 20 klon hasil silangan Granola x transgenik Katahdin SP951 (D). Atlantik dan Granola digunakan sebagai kontrol rentan, sedangkan transgenik Katahdin sebagai kontrol tahan. Pengamatan dimulai ketika muncul gejala awal, yaitu pada 26, 32, 39, 46, dan 53 hari setelah tanam. Ketahanan tanaman semakin menurun dengan bertambahnya periode pengamatan, diikuti meningkatnya intensitas penyakit dan AUDPC. Semua klon yang diuji menunjukkan keragaman dalam ketahanan fenotipik terhadap hawar daun P. infestans. Klon-klon hasil silangan Atlantik x transgenik Katahdin SP951 mempunyai nilai AUDPC 697, yang hampir sama dengan transgenik Katahdin SP904 yaitu 698,5. Klon-klon Granola x transgenik Katahdin SP951 mempunyai nilai AUDPC 687,5 lebih kecil dibandingkan transgenik Katahdin SP904. Hasil penelitian ini juga menunjukkan bahwa klon-klon tersebut mempunyai ketahanan yang lebih tinggi dibandingkan transgenik Katahdin SP904. Pada pengamatan 46 hari setelah tanam atau 20 hari setelah infeksi diperoleh tiga klon tahan yaitu B49 (skor 7,5), C111 (skor 7,1), dan D26 (skor 7,3). Ketahanan ini lebih tinggi daripada transgenik Katahdin SP904 (skor 5,1) dan transgenik Katahdin SP951 (skor 6,4). <br /><br />ABSTRACT. Ambarwati, AD, Herman, M, Listanto, E, Suryaningsih, E and Sofiari, E 2012. Resistance Testing on Transgenic and Nontransgenic Potato Clones Against Late Blight Phytophthora infestans in Confined Field Trial. Transgenic potato Katahdin event SP904 and SP951 containing RB gene, which were isolated from a wild diploid potato species, Solanum bulbocastanum. RB gene showed durable resistance with broad spectrum to all known races of P. infestans in the USA. In development of potato resistant to late blight P. infestans in Indonesia, Katahdin transgenic were used as a resistant donor and crossed with susceptible varieties i.e. Atlantic and Granola. Clones derived from the crossing were molecularly analyzed and had RB gene contain. Experiment was conducted to assess the resistance of the clones derived from crossing of Katahdin transgenic and nontransgenic to P. infestans in confined field trial (CFT), located at the Indonesian Vegetable Research Institute (IVEGRI), Lembang from October 2009 to March 2010. Several clones tested were 12 clones of Atlantic x Katahdin transgenic SP904 (A); 15 clones of Atlantic x Katahdin transgenic SP951 (B); 17 clones of Granola x Katahdin transgenic SP904 (C); and 20 clones of Granola x Katahdin transgenic SP951 (D). Atlantic and Granola were used as susceptible control whereas Katahdin transgenic as resistant control. Observation was started as late blight symptoms and detected at 26, 32, 39, 46, and 53 days after planting. Plant resistance decreases with increasing period of observation, followed by increasing disease intensity and AUDPC. All clones tested showed variation in phenotypic resistance to late blight P. infestans. Clones derived from crossing of Atlantic x Katahdin transgenic SP951 had AUDPC score 697 and almost similar to Katahdin transgenic SP904 (698.5). Clones derived from crossing of Granola x Katahdin transgenic SP951 had AUDPC score 687.5 and smaller than Katahdin transgenic SP904. The results also indicated that these clones had higher resistance than Katahdin transgenic SP904. Observation at 46 days after planting or 20 days after infection resulted three resistant clones i.e. B49 (score 7.5), C111 (score 7.1); and D26 (score 7.3). This resistance was higher than Katahdin transgenic SP904 (score 5.1) and Katahdin transgenic SP951 (score 6.4). <br />

RESISTANCE EVALUATION ON POPULATIONS OF CROSSES BETWEEN TRANSGENIC POTATO KATAHDIN RB AND NON-TRANSGENIC ATLANTIC AND GRANOLA TO LATE BLIGHT (Phytophthora infestans) IN CONFINED FIELD TRIAL

Late blight resistance gene (RB gene) isolated from Solanum bulbocastanum, is a broad resistance gene against all races of Phytophthora infestans. The gene was transformed into Katah-din event SP904 and SP951 using Agrobacterium tumefaciens and these transgenic plants have been crossed with susceptible potato cultivars Atlantic and Granola. Populations of the crosses have been molecularly characterized for the integration of the RB transgene. The study aimed to evaluate the resistance of the populations of crosses between transgenic Katahdin RB and susceptible non-transgenic parents (Atlantic and Granola) to late blight in a confined field trial at Pasir Sarongge, Cianjur, West Java. A total of 84 clones originated from four popula-tions were evaluated for resistance to late blight. These included 22 clones of Atlantic x transgenic Katahdin SP904, 16 clones of Atlantic x transgenic Katahdin SP951, 19 clones of Granola x transgenic Katahdin SP904, and 27 clones of Granola x transgenic Katahdin SP951. Observations of the late blight infection were conducted when late blight symptoms were detected, i.e. at 56, 60, 63, 70, and 77 days after planting (DAP). The result showed there were high variations in the resistance level of all the 84 clones tested. Clones of crosses between susceptible parents (Atlantic or Granola) and resistant parents (transgenic Katahdin SP904 or Katahdin SP951) showed a similar pattern based on the area under disease progress curve (AUDPC) value, i.e. 377.2 greater than the AUDPC of the resistant parents (180.1), but smaller than that of the susceptible parents (670.7). Observation at 77 DAP resulted four resistant potato clones having resistance score of 7.0-7.6, higher than the transgenic parents Katahdin SP904 (4.6) and Katahdin SP951 (6.8), i.e. clone B8 (Atlantic x transgenic Katahdin SP951) with resistance score of 7.6 and clones B26 (Atlantic x transgenic Katahdin SP951), C183 (Granola x transgenic Katahdin SP904), and D89 (Granola x transgenic Katahdin SP951) with resistance score of 7. These four transgenic potato resistant clones need to be further developed as promising potato clones to late blight.<br /><br />