Cytomorphological Characterization of Wide Cross Derivatives in Rice

Wild species of Rice offer an important source of variability for improvement of cultivated Rice. Wide hybridization is the only way to transfer useful genes from wild species into cultivated Rice. In order to utilize the resistant potential of Oryza rufipogon to various biotic and abiotic stresses, this species was crossed with cultivated varieties of Oryza sativa. The crossability between O. sativa and O. rufipogon varied from 17.5-33 (%). The highest crossability was observed in IR-6/O. rufipogon (33%) and least in KS-282/O. rufipogon (17.5%). Based on crossability, IR-6 showed a close affinity with O. rufipogon. All the F1 hybrids were intermadiate in plant morphology between the two parents. The F1 hybrids showed both mid parent and high parent hetrosis for various quantitative traits. All the F1 hybrids showed normal meiosis with remarkably high chromosome pairing. Therefore favorable alleles can be easily introgressed from the wild O.rufipogon into cultivatd Rice O. Sativa.