Abstract
Forage and seed yields of diploid crested wheatgrass, Agropyron cristatum (L.) Gaertu., were reduced sharply by selling. Some progenies were much more sensitive to selfing than others. Vigor and fertility reductions averaged 44.9 and 43.4%, respectively, in 15 S1 progenies. Inbreeding depression of induced‐autotetraploid crested wheatgrass was much less than that of comparable diploids. Forage yields of seven induced‐tetraploid S1 progenies declined 17.3%, compared with a 54.9% reduction for their exact diploid counterparts.Possible causes of rapid loss of vigor in natural autotetraploids are discussed. Newly synthesized autotetraploids—includiug crested wheatgrass; corn, Zea mays L.; Italian ryegrass, Lolium multillorum Lam.; and alsike clover, Trifolium hybridnm L.—show a much lower degree of inbreeding depression than old natural autotetraploids such as alfalfa, Medicago sativa L.; orchardgrass, Dactylis glomerata L.; and crested wheatgrass, Agropyron desertorum (Fisch. ex. Link) Schult. An accumulation of chromosome aberrations and unfavorable gene combinations in species buffered by autoploidy is offered as a major cause of excessive inbreeding depression in natural autotctraploids. The degree of inbreeding depression in natural autotetraploid species may give an indication of their relative ages.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.