A review of pear and pear breeding, and studies of pear and plum seedlings

arborescence arbre fruitier breeding methods calidad chromosome number ciruela enfermedades de las plantas etapas de desarrollo de la planta fruit trees histoire historia history maladie des plantes nombre chromosomique nutritive value pears pera plant anatomy plant developmental stages plant diseases plums poire prune prunus domestica pyrus communis quality resistencia invernal tree form valeur nutritive valor nutritivo variedades varieties winter hardiness