Identifikasi gen aroma pada progeni-progeni backcross Antara varietas ciherang dengan pandan wangi

Abstract

Marker-assisted PCR has been considered as the most potential method for fragrant selection. RM223 is the only suitable marker to identify mutated badh2 gene of Pandan Wangi. This research applies RM223-assisted PCR in the introgression of fragrant gene (mutated badh2) of Pandan Wangi variety, to engineer non-transgenic fragrant variety with good agronomic traits as those of Ciherang. Gene introduction was carried out through site-directed crossing; Pandan Wangi was crossed and backcrossed to Ciherang until heterozygot BC5F1, followed by selfing to obtain homozygot BC5F2. RM223-assisted selection was conducted in each cross and backcross generation. RM223 was able to identify native, mutated and heterozygot badh2 of Ciherang, Pandan Wangi, and their cross/backcross progenies, respectively. Therefore, the introgression of mutated badh2 within progenies were observed, as well as the statues of badh2 gene (native/mutated) and alleles (homozygot/heterozygot). Further backcross and selfing to obtain BC5F2 is in progress.

PCR berbantuan marka spesifik merupakan metoda deteksi aroma padi yang pada saat ini dianggap paling potensial. RM223 merupakan satu-satunya marka yang dapat mengidentifikasi badh2 termutasi varietas Pandan Wangi. Penelitian ini mengaplikasikan PCR berbantuan marka RM223 pada introgresi gen aroma (badh2 termutasi) varietas Pandan Wangi, dalam rangka merekayasa varietas nontransgenik beraroma Pandan Wangi dengan karakter agronomi sebaik padi Ciherang. Introduksi dilakukan secara persilangan terarah (site-directed crossing), dimana Pandan Wangi disilang dan dibackcross dengan Ciherang hingga diperoleh BC5F1 heterozygot yang kemudian diselfing untuk mendapatkan BC5F2 homozygot (Ciherang aromatik). Pada setiap generasi persilangan/backcross dilakukan seleksi PCR berbantuan marka RM223. Didapatkan RM223 dapat mendeteksi badh2 utuh pada Ciherang, termutasi pada Pandan Wangi serta heterozygot pada progeni persilangan hingga BC3F1. Oleh karena itu dapat teramati introgresi gen badh2 termutasi pada progeni hasil persilangan/backcross, dan status gen (native/termutasi) serta alel (homozygot/ heterozygot) badh2. Backcross dan selfing untuk mendapatkan BC5F2 sedang dalam proses.