Mutation Breeding

You would like to know about the usefulness of experimentally induced mutations in plants? Then visit this link Mutation Breeding

Further useful basic and practical information on methods of mutation breeding is given in the “Mutation Breeding Manual” edited by F.S.MEDINA, ETSUO AMANO and SHIGEMITSU TANO (2004), available now online under   <http://www.fnca.jp/english/mb/mbm/e_mbm.html>

 
Induced mutations in Melilotus

Melilotus, called sweet clover, comprises several species. Most but not all of them contain a bitter compound, which can be converted by enzymes into coumarin. This substance reduces blood coagulation and for this purpose is applied as a medicine. When taken up in larger quantities, as by grazing cattle, it could be dangerous in causing continuous bleeding. Therefore plant breeders have tried for decades to select sweet clover strains lacking this compound. Some were successful by employing hybridisation among distantly related species, embryo culture and grafting. Others tried to use mutation induction as a tool to get rid of this harmful compound. You want to know more about such experiments? Visit this link: Induced mutations in Melilotus

Many of the mutants observed carry distinct morphological alterations. These illustrate a range of ontogenetic misregulations caused by gene mutations,  deletions and possibly other events. Rather surprising is the frequency of disturbances in the regulation of leaf and flower development. Melilotus normally has typical trifoliate leaves and the rather complicated papilionaceous or ‘butterfly’ flowers common to leguminous plant species. If these characteristics are changed, two main criteria of botanical classification are lost. More details can be found on this link: developmental misregulation

More recently, Melilotus is being used as a model species for molecular genetics in the family of Leguminosae, a family that comprises numerous crop plants like peas or beans, as well as forage plants like clovers and alfalfa. A most valuable unique characteristic of this family is the ability to establish symbioses with particular bacteria and in this way obtain the required nitrogen from the air instead of from the soil or fertilizer. You want to know the status of this kind of research, visit the following website of the University of California at Los Angeles: Investigations on Sweetclover Molecular Biology and Genetics

 

FAQ

“Do you really believe, that the treatments leading to induced mutations have any relationship to the processes driving natural evolution?”

“Randomly appearing mutations are selected by the environment and the positive ones have a better chance for accumulation in the subsequent generations.  This evolutionary concept makes sense for unicellular populations, but is this really an applicable model for the highly differentiated multicellular organisms with their specialized tissues and organs? Higher plants have a remarkable ability to react to and interact with the environment. But the (re-)acting genes are active only in certain somatic tissue, during certain periods and not in the generative organs. How can they be selected for a better chance of transmission into the subsequent generations?”

“Is it true, that evolution is mainly based on elements regulating gene activities than on protein coding genes? If so, does this also apply to the mutants obtained after mutagenic treatments?”