Morphological Characteristics And Development Of Tannin Cells In The Fruit Of Persimmon Germplasm And Relations With Its Classification

Tannin cells in persimmon fruit were observed by light microscope. Tannin cells were obtained by pressing mature soft fruit and filtration and purifying or spreading mature soft fruit flesh direct to the holding flake. 204 cultivars which included several species and four types (PCNA, PVNA, PCA, PVA) were selected for this study. Tannin cells' developments during the all seasons of 5 cultivars were observed and analyzed. The results as follows:1. Tannin cells were distinguished easily with parenchymatous cells whatever dyeing them even though in the ovary.2. Tannin cells appear various shape, size and surface character on tannin cells in different cultivars, different fruits or even in the same fruit. Shape of tannin cells can be classified six groups in mature fruits of different varieties, which conclude threadlike, long, oblong, round, polygon and needle;Surface characters of tannin cell can classified thorn, tumour, concave, smooth.3. Size of tannin cells in mature fruits is about 3 times than that of in young fruits. A large number of tannin cells with different shape exist mainly in mesocarp which were about 2 times bigger than those of in epicarp. Tannin cells exist in mesocarp as individuals or bundle and gobbet in some cultivars.4. PCNA and PCA varieties are partly different in developments of tannin cells. The length and width of tannin cells enlarged with fruit development, its length increased rapidly, and width of tannin cells grew slowly. The size of tannin cells of PCNA cultivar "Jiro" are smaller than those of 4 PCA cultivars at the same period. About 50 days after blooming, the tannin cells development seems to cease 30 days or more, and then cell size slight fluctuate until fruit mature, while cell size of other 4 PCA cultivars enlarged constantly until fruit mature. It showed that the individual development of tannin cells between PCNA and PCA cultivar was different obvious.5. Tannin cells also existed in the fruit of some persimmon species. The shape of cell is similar on the whole among species, but they showed differences on quantity, size and color. D. lotus and D. glaucifolia had many small size tannin cells which existed in an agglomerate form, thus with much fewer parenchyma cells. Tannin cells of D. eathayensis tended to be very small, which were almost not detectable under a low-resolution microscope. In contrast, tannin cells of D. oleifera were larger than those in other species. D. oleifera, D. lotus, D. glaucifolia, and D. eathayensis usually had colorless tannin cells, whereas D. nitida and red purple and D. erantha had green-yellow tannin cells.6. Tannin cells showed obvious difference in different types of persimmon. Tannin cells in almost astringent varieties were colorless except some brown cells appear in a few of them, while those in non-astringent varieties can be found more or less browning cells. The sizes of tannin cell in astringent cultivars were bigger or fatter, and in non-astringent cultivars were smaller or thinner. In PCNA cultivars, a few of coacervate brown tannin cells can always be found besides many concretionary brown tannin cells , and the cells always dispersed evenly in the flesh, so brown specks in the flesh are small or fine. In PVNA cultivars, many contracted tannin cells with hollow hole on the cell surface, which exsit as bundle around seeds, can be found, so, large and high density brown specks can be seen in the flesh.