关键词: 主成分分析, 主成分分析

Abstract: In order to study the reason for ‘male pear’ ‘female pear’ occurrence, and the differences between ‘male pear’ and ‘female pear’, the pear calyx shed or persistence and ‘male pear’, ‘female pear’ were analyzed in this thesis. The author reviewed the effects of pear calyx shed factors, including breed characters, pollination varieties and pollen amount, plant growth regulators, light, tree age and growth, trim and load, ordinal position of inflorescence, and reviewed differences between calyx shed fruit and persistent calyx fruit, including fruit shape, diseases and pests, mineral elements and plant hormone contents, microstructure, quality and other aspects. Reasons for pear fruit quality differences between ‘male pear’ and ‘female pear’ were analyzed, and developing study on ‘male pear’ and ‘female pear’ was prospected in the future.