Distribution of stone cell in Asian, Chinese, and European pear fruit and its morphological changes

Abstract

This study was conducted to microscopically verify the distribution and morphological changes occurring in stone cells during fruit growth in order to determine physiological changes occurring in stone cells in pear fruits. European pear (P. communis L. cv. ‘Bartlett’), Chinese pear (P. bretschneideri Rehd. cv. ‘Yali’), and Asian pear (P. pyrifolia Nakai cv. ‘Niitaka’) were collected from three trees of each cultivar for microscopic observation at 60 DAFB. Also, ‘Niitaka’ pear fruits were harvested at development stages of 30, 60, 90 and 150 DAFB. Stone cells were observed via light microscopy (LM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The stone cells were found to be clustered less profoundly in the ‘Niitaka’ and ‘Yali’ pears than in ‘Bartlett’ pears, and the sizes of the clusters were smaller. Also, the stone cells were clustered closer to the epidermis in the ‘Niitaka’ and ‘Yali’ pears than in the Bartlett pears. Stone cells appeared in cluster structures beginning at 60 DAFB. The relative decrease in the quantity of stone cell clusters in the flesh was attributed to the fact that stone cells were no longer being generated, and the flesh cells increased dramatically in size. Developing and completed stone cells existed together within the same stone cell cluster.