Principles of Cultivar Development: Theory and technique

aabb Agricultural Agronomy apomixis backcrossing breeder seed bulk chromosome clones combining ability components Crop Sci cross-pollinated cultivar cultivar development cycle of selection desired diallel diploid environment epistasis epistatic evaluation F₁ F₂ plants Fehr female parent flowering foundation seed frequency gametes genetic gain genetic variability genotypes germplasm grown half-sib families half-sib seed haploid heritability heterosis heterozygote heterozygous homozygosity homozygous hybrid seed improvement inbred lines inbreeding inbreeding depression increase individual plants interaction intercrossing involved Iowa Iowa State University isolines locations loci maize male parent male-sterile plants mass selection mating meiosis method mixture msms multiline mutation number of parents number of plants obtained open-pollinated percent performance pest plant breeders plant introductions plots pollen procedure progeny testing random reciprocal crosses recombination recurrent parent recurrent selection release replicated tests resistance rows Season seed production self-pollinated selfed seed single cross soybean species sterility superior testcross tester variance yield