An Anatomical Study Of Rind Development And Splitting Occurrence In Navel Orange

'Skagg's Bonanza' navel orange and 'Newhall' navel orange that are widely grown at Gannan, Jiangxi province were used as experiment materials in this study. Histological structural traits were compared between the development of 'Skagg's Bonanza' and 'Newhall' and the development of normal fruits and cracking fruits of 'Skagg's Bonanza' sampled from different positions of rind, including upper, equator and pedicel. Factors that affected the splitting of navel orange were also discussed based on preview research. The results were as follows:1. The anatomization structure of rind of navel orangeStructure of the rind: The rind of navel orange is comprised of exocarp, mesocarp and endocarp. Exocarp is composed of a layer of epidermal cells that were covered with cuticle, subepidermal cells and oil gland layers cells. Mesocarp is consisted with retiary structural cells; Vascular bundle adheres to the mesocarp.Growth of the rind: Cells of epidermis arranged less regularly and compactly since the middle ten-day of August and the interspaces were emerged after September. With increasing of the thickness of cutin layer and oil gland layers, the distribution of density of oil gland layers and albedo layers was decreasing.Diversities among different positions of the rind: The thickness of subepidermal of upper is less than the equator and pedicel. Contracting with pedicel and equator which have different thickness between various species, upper has thinner oil gland in despite of dissimilar species. The largest oil gland is distributed at pedicel and the smallest are allocated at the upper. The oil glands have a nearly rotund shape at equator while they usually have an elliptic shape at pedicel. The lowest dentist of albedo layers is allocated at the upper.2. The differences of the anatomization structure of rind of navel orange Diversities of epidermis and subepidermal: Subepidermal of the upper rind of'Skagg's Bonanza' navel orange was thinner than 'Newhall' navel orange. The epidermis of 'Newhall' navel orange arranged more regularly than that of 'Skagg's Bonanza' navel orange after August. The epidermis of 'Skagg's Bonanza' navel orange waves greatness, have the bigger interspaces between cells.Differences of the oil gland: The thickness of oil gland layers of equator and upper of 'Skagg's Bonanza' navel orange, especially the former, was thinner than 'Newhall' navel orange. The density of oil gland layers of'Skagg's Bonanza' decreased quicker than that of 'Newhall' navel orange during the development of 'Skagg's Bonanza'. The oil glands of 'Newhall' navel orange are smaller than those of 'Skagg's Bonanza' before September, which turn to the opposite since September. The oil glands of 'Skagg's Bonanza' have a nearly rotund shape at equator while they have an elliptic shape at pedicel, but almost every oil gland of 'Newhall' navel orange has elliptic shape which appearances more evidently at pedicel.Differences of the albedo layers: Comparing with the 'Newhall' navel orange, the...