Rice Artificial Hybridization for Genetic Analysis

Artificial hybridization has probably been practiced since ancient time; however, the science of genetics did not initiate until Gregor Mendel conducted a series of crosses between different pure lines of garden pea and made careful observations and systematical analyses of their offspring. Artificial hybridization or crossing between carefully chosen parents has been and still is the primary way to transfer genes from different germplasm for self-pollinated rice. Through gene recombination, novel genetic variation is created by different arrangements of genes existing in parental lines. Procedures of artificial hybridization involve the selection of appropriate panicles from representative plants of the female parents, the emasculation of female parents, and the pollination of emasculated panicles with abundant pollens of selected male parents. Of the numerous proposed methods, hot water and vacuum emasculation have proven to be the most robust and reliable ones. A successful and efficient hybridization program also relies on the knowledge of parental lines or germplasm, the reproductive biology and development of rice, the conditions needed to promote flowering and seed development, and the techniques to synchronize flowering of diverse parents.