Perbaikan Genetik Padi Gogo Lokal Aceh (Oryza sativa L.) melalui Iradiasi Sinar Gamma untuk Genotipe Umur Genjah dan Produksi Tinggi

Abstract

Local rice cultivars that have resistance to biotic and abiotic stresses still have weaknesses in terms of long life and low production. In general, local cultivars have a relatively long lifespan when compared to superior varieties that have been released by the government. This weakness has caused farmers to rarely cultivate local rice cultivars commercially. Local rice is tolerant to stress but has a long lifespan, so it needs a touch of plant breeding to shorten the lifespan of the plant so that it can be grown throughout the year or more than once a year. Plant breeding programmes to assemble varieties begin with the determination of programme objectives, the provision of genetic material to increase diversity through crossing or mutation with radiation techniques, selection, preliminary tests, multilocation tests, and multi-season tests and then released as new varieties. The purpose of the upland rice breeding programme in this study is to increase genetic diversity through gamma irradiation so that mutants with short-lived and high-yielding traits are expected to be obtained. For this purpose, local Acehnese cultivars were used as plant breeding material. The local Aceh upland rice cultivars explored, namely Arias Putih, Gameso, and upland rice variety Inpago Unsoed 1 as a comparison of drought-resistant varieties and Ciherang varieties as a comparison of drought-sensitive varieties to be tested for drought by gravimetric method. Cultivars that were tolerant of drought stress were used as research materials. Furthermore, the Lethal Dose (LD50) test was conducted to obtain the dose of gamma irradiation in this study. After obtaining LD50, 3 doses of irradiation were taken with the highest dose of 100 grey above LD50 224.14 Gy, namely (100 Gy, 200 Gy and 300 Gy) for irradiation on the Mutan-1 (M-1) population, then planted in the field until harvest. The M-1 plant population was observed for morphoagronomic characters. This study was conducted until the M-2 generation. In the Mutan-2 (M-2) population, the value of genetic diversity, phenotypes and heritability were calculated. This research has the ultimate goal of assembling early maturing and high yielding upland rice varieties so that in the end drylands can be utilised throughout the year as a national rice granary in an effort to support national food security.