lntrogression of Bcterial Leaf Blight Resistance Gene from Oryza Minuta J:B. Presl. Ex C. B. Presl. into New Rice Type (Oryza sativa L.)

Abstract

F 1 Hybrids, backcrossp rogenies, advancedi ntrogressionl ines (2n=24) and monosomica lien addition lines or MAALs (2n=25) were successfully produced following embryo rescue between an elite new plant type (NPT) breeding line of Oryza sativa (2n=24, AA) and a wild species, O. minuta (2n=48, BBCC). F 1 hybrids performance were intermediateb etweent hep arents. TheF 1 hybrids had 36 chromosomesin dicating having 12 chromosomeA from O. sativa and 12 Band 12 C from o. minuta. THE BACK CROSS progenies had different chromosome number indicating abnormal meiosis of the hybrids and back crossp rogenies. Plant with 2n=24 and 25 chromosomesw ere obtained in BC4FI. The hybrids and backcross progenies were susceptible to bacterial leaf blight (BB). However, several of the 2n=24 plants derived resistant plant to bacterial leaf bligkt race 1 of the Philippines races. The gene is differentf rom introgressedg ene intio rice from O. longistaminata( Xa21)a ndf rom o. Minuta Acc. 101141.