Regeneration and interspecific hybridization in annual Medicago species

When and at which stage in Medics' flowers, pollan grains may grow and fertilize the pistile? How the fragile flowers of medics may be emasculated for inter and intra-specific hybridization, with high percentage of success? This study was carried out to answer these questions. To find the exact time of pollan maturation and their fertilability, the flowers of two species of medics, Medicago polymorpha and M.rigidula were visited at various sizes. And stages Pollan sacs were removed and cultured on agar based media. The best size of the flowers for emasculation before self fertilization was recognized for the two species. This size was about the stage before the tip of the standard petal past its calyx teeth. To emasculate the flowers on the mentioned stage, various density of ethilic alcohol, suction pump, surgical blade and fine/ needle were used. The best method to emasculate the flowers was opening the flowers through standard petal by surgical blade and removing the pollan sacs by suction pump or fine needle. After hybridization, to cover the fragile emasculated flowers to keep them fresh and moist, a glass tube was used, instead of paper bag, for 15 days at 25 degree of centigrade.