DEVELOPMENT OF JAPONICA TYPE CYTOPLASMIC MALE STERILE (CMS) RICE LINES FOR COMMERCIAL HYBRID RICE IN MEDITERRANEAN ECOLOGICAL CONDITION

Abstract

Hybrid rice has an average 15 % to 20 % yield advantage over inbred lines. The availability of stable cytoplasmic male sterility system is vital for commercial hybrid rice. The experiment was conducted to develop japonica type CMS lines of national rice varieties. National varieties were tested to determine as maintainer, CMS or restorer features via test cross. The test crosses were made by using 19 japonica type national rice varieties and 21 CMS lines and 1 restorer line. All national rice varieties which tested are determined maintainer features. In addition to, 5 CMS introduction lines and 1 restorer lines adapted Mediterranean ecological condition for hybrid breeding process. Two maintainer were backcrossed for 6 generations and it was developed similar agronomic features and 100% spikelet sterile CMS lines. For production of CMS lines Osmancik-97 and Kiziltan, it was employed wild abortive rice which is CMS V20A. Successive backcrossing of varieties succeeded to produce completely male sterile CMS lines. Wild abortive cytoplasm did not affect agronomic characteristic. Since Osmancik-97 is one of the most popular varieties and it was used as a donor gene for new varieties, the WA-CMS lines of Osmancik-97 and Kiziltan will be useful for hybrid rice breeding.