00545nam a2200133Ia 4500008004100000082002300041100001800064245010900082260007100191300001300262490008200275600001600357650003800373140224s9999    xx            000 0 und d  a575.127.5:631.5 J2  aThomas, Mary.  aBack crossing; the theory and practice of the backcross method in the breeding of some non-cereal crops.  aCambridgebCommnwealth Bureau of Plant Breeding and Geneticsc1952  avi,136p.  aCommnwealth Bureau of Plant Breeding and Genetics, Technical Communication 16  aMary Thomas  aCrossing over (Genetics),Breeding