Resistance Test toward of 48 Lines Rice to Blast Disease (Pyricularia oryzae) Race 001
| Main Author: | Fitrianna, Yulita |
|---|---|
| Other Authors: | Widyastuti, Utut, Aswidinnoor, Hajrial |
| Terbitan: |
IPB (Bogor Agricultural University)
, 2011
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| Subjects: | |
| Online Access: |
http://repository.ipb.ac.id/handle/123456789/51244 |
Daftar Isi:
- Blast disease, caused by Pyricularia oryzae Cav., is one of the major fungal diseases infected rice (Oryza sativa L.) in Indonesia. The aim of this research was to examine the resistance of rice from the infection of P. Oryzae race 001 and to detect the existance of Pi-ta gene in resistant lines of rice. Resistance evaluation to blast disease (Pyricularia oryzae) on Cisadane (resistant), Kencana Bali (susceptible) as control, and 48 lines of rice was carried out in the green house by using injection inoculated method with P. oryzae race 001. Rice seedling were planted on sterilize soil, and sixteen days old of rice were soaked in the fungal spore suspension (105 spores/ ml) in the dark for 24 hours, and moved to the light. Rice disease was observered on 7-9th days after infection. There were 2 step screening of blast-resistant, which screening I performed a total of three replicates and screening II performed from selected plant in screening I a total of two replicates for each line of rice, with 10 plants in each replication. The result of second screening at green house showed that 13 lines resistant to P. oryzae 001 were IPB140-F-2-1, IPB115-F-4-2-2, IPB113-F-2-2, IPB107-F-7-3, IPB140-F-5, IPB149-F-2, IPB149-F-8, Martapura, IPB149-F-4, IPB149-F-5, IPB113-F-1, IPB102-F-92-1-1, IPB107-F-5-1 with the percentage of resistance ≥ 80 %. Two pairs of DNA primers specific to the dominant indica Pi-ta gene were designed from DNA sequence in gene bank with accession number AF207842 to amplify the Pi-ta DNA fragments by polymerase chain reaction (PCR) method. The results revealed that all of 13 resistant and 2 susceptible lines (IPB107-F-18-4-2 and IPB107-F-16E-6) of rice carrying Pi-ta genes, even in Kencana Bali. The previous experiment shown that Kencana Bali does not have Pi-ta resistance gene. It is expected that Kencana Bali has deletion of Pi-ta resistance gene in the end part of exon 2. Further more, those results also indicated that Pi-ta gene did not confer resistance to race 001 of Pyricularia oryzae. Resistance to P. oryzae race 001 might be controlled by different resistant gene.
- Penyakit blas yang disebabkan oleh cendawan Pyricularia oryzae Cav. merupakan salah satu penyakit utama yang menyerang padi di Indonesia. Penelitian ini bertujuan untuk menguji tingkat ketahanan galur-galur padi terhadap serangan penyakit blas dan mengidentifikasi keberadaan gen ketahanan Pi-ta pada galur padi yang tahan. Penelitian dilakukan dengan menggunakan padi varietas Kencana bali (peka) dan Cisadane (tahan) sebagai kontrol serta 48 galur padi hasil seleksi Program Pemuliaan di Departemen Agronomi dan Hortikultura IPB dengan metode injeksi menggunakan P. oryzae ras 001. Padi berumur 16 hari setelah tanam diinokulasikan dengan 1 ml suspensi spora (104-105 spora/ml) isolat P. Oryzae. Tanaman diinkubasi pada kondisi gelap lalu dipindah ke ruang terang dan dilakukan pengamatan hingga 7-9 hari setelah infeksi. Pengujian tahan blas dilakukan 2 tahap, yaitu penapisan I dilakukan sebanyak 3 ulangan dan penapisan II dilakukan sebanyak 2 ulangan untuk masing-masing galur terpilih dari penapisan I, dengan 10 tanaman pada tiap ulangan. Pengamatan hingga penapisan II menunjukkan adanya 13 galur padi tahan terhadap P. oryzae ras 001 yaitu IPB140-F-2-1, IPB115-F-4-2-2, IPB113-F-2-2, IPB107-F-7-3, IPB140-F-5, IPB149-F-2, IPB149-F-8, Martapura, IPB149-F-4, IPB149-F-5, IPB113-F-1, IPB102-F-92-1-1, IPB107-F-5-1 dengan persentase ketahanan ≥ 80 %. Dua pasang primer spesifik untuk gen Pi-ta didesain dari sekuen DNA dengan nomor aksesi AF207842 untuk mengamplifikasi fragmen DNA gen Pi-ta dengan metode PCR. Hasil identifikasi gen ketahanan Pi-ta menunjukkan bahwa 13 galur tahan maupun 2 galur rentan (IPB107-F-18-4-2 dan IPB107-F-16E-6) mempunyai gen Pi-ta, bahkan pada Kencana Bali. Percobaan sebelumnya, menunjukkan bahwa Kencana Bali tidak memiliki gen ketahanan Pi-ta. Diduga bahwa varietas Kencana Bali mengalami delesi di daerah bagian belakang ekson 2. Hasil identifikasi gen Pi-ta juga mengindikasikan gen Pi-ta tidak spesifik berperan dalam mekanisme pertahanan tanaman pada galur-galur padi ini, sehingga diduga ada gen lain yang berperan dalam proses ketahanan tanaman padi terhadap serangan P. oryzae ras 001.