Ciri Morfologi, Fisiko-Kimia dan Kerintangan Dua Titisan Padi Kemandulan Jantan Sitoplasma (CMS) Baru

CMS (cytoplasmic male sterile) line is one of the most important hybrid parents in hybrid rice production technology using Three-Line systems. Test-crosses for selection of candidate local maintainer lines were conducted using 24 rice varieties and two CMS-WA (wild abortive) lines IR78374A/B and 1A/B. The F 1 of the two combinations, namely IR78374A/P519 and 1A/MR243 had less than 10% spikelet fertility (6.4 and 7.2%, respectively), indicated that P519 and MR243 are partially maintainers and could be used for the development of new locally adapted CMS lines. As a results, two CMS lines, namely 0025A/B and 0047A/B were generated after 5 to 6 successive backcrossing of IR78374A with P519 and 1A with MR243. The CMS 0025A/B and 0047A/B lines had maturation age which is comparable to other commonly grown inbred varieties. The percentage of stigma exertion rate for CMS 0025A/B and 0047A/B were 17.9 and 21.3%, respectively, lower than that of IR78374A/B (43.2%). Both showed poor out-crossing rate. CMS 0025A/B and 0047A/B are classified as long and slender grain. They had intermediate amylose content. Their gel consistency was hard, comparable to that of MR263 (medium).  CMS 0025A/B and 0047A/B lines were also moderately resistant to foliar blast disease and brown planthopper infestation.