Introduksi toleransi genangan berbantuan marka sub1 Pada varietas ciherang

Abstract

Perubahan iklim global yang sulit diramalkan mendesak perlunya pengembangan varietas padi toleran banjir/genangan. Mengingat varietas alami toleran genangan kurang ekonomis untuk kultivasi skala besar, maka penelitian ini bertujuan untuk mengintroduksi toleransi genangan pada varietas popular dengan produktivitas tinggi (Ciherang). Metoda introduksi dilakukan secara persilangan terarah (site-directed crossing), dimana donor sub1 disilangkan dengan host Ciherang, dan F1 dibackcross dengan Ciherang untuk mendapatkan BC1F1. Pada setiap generasi persilangan/backcross dilakukan uji genangan, diikuti PCR dengan marka sub1, yang dipilih berdasarkan hasil validasi berbagai marka sub1 kodominan (RM464A, RM219) dan dominan (C173, AEX1) yang tersedia pada saat ini. Hasil penelitian mendapatkan F1 dan BC1F1 Ciherang toleran genangan. Marka dominan AEX1 merupakan marka sub1 yang paling sesuai. Hasil analis is PCR mendapatkan pita sub1 pada progeni (F1, BC1F1) yang tadinya tidak ada. Menunjukkan keberhasilan transfer gen sub1 dari donor ke host dan mengkonfirmasi toleransi genangan progeni timbul akibat introgresi sub1, bukan karena mekanisme escape.

Unpredictable global climate changes have triggered the need for engineered submergence-tolerant rice. Due to in-economical of native submergence tolerant varieties for large scale cultivation, therefore, this research aims to introduce submergence tolerance into high productivity popular rice. Introduction was carried out through sitedirected crossing, where sub1 donor was crossed with Ciherang host, and the F1 progenies were further backcrossed to Ciherang to obtain BC1F1 progeny. Submergence test was performed in every cross/backcross generation, followed by PCR using sub1 marker, which was chosen based on validation results of currently available co-dominant (RM464A, RM219) and dominant (C173, AEX1) sub1 markers. F1 and BC1F1 submergence-tolerant Ciherang were obtained. AEX1 dominant marker was the most appropriate for this research. PCR results showed additional sub1 band within progeny (F1, BC1F1) that was not presence previously. Indicating the success of sub1 gene transfer from donor to host, as well as confirming that progenies-submergence tolerance was due to sub1 introgression, not escape mechanisms.