| dc.description.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. | en_US |
