|
In this study, four citrus varieties Fengjie navel orange (Citrus sinensis Osbeck), Navel Orange (C.sinensis Osbeck), tangerine (C. reticulata Blanco) and mandarin (C. reticulate Blanco) for the test material, the use of paraffin Technology the peel diseases lighter to heavier development process studies to understand the disease at all stages of the pericarp tissue structure, relatively easy to disease and illness is not easy peel citrus species differences in organizational characteristics, the main results are as follows: 1. physiological disease 1 ) fruit oil blotch begins yellow cortex with 4-7 layers of cells, the victim becomes flat parts of the cell cytoplasm contraction in the central cell, epidermal cells are still neat, compact; metaphase cells become narrow, cytoplasm disorders, reduction in cell wall surrounding into a thin layer; arrive late disease epidermal cells, cytoplasmic degradation, oil gland is still intact; final upper oil gland cell rupture, some oil gland hurt, inward depression. 2) fruit leaf spot begins with oil gland becomes flat, oil gland surrounding cells became flat, located in the central cell cytoplasm contraction; metaphase cells cellular aberrations cause the oil concave; late, yellow skin and white skin folds inward, wavy oil gland severely deformed; late, cell degradation, oil gland rupture, yellow outer cortex by bacterial infection. (2) mechanical damage to mechanical damage like diseases like disease first occurred in two cortical white yellow oil intercellular cortical areas of transition, post outside the cortex to yellow, white cortex internal expansion. 3 hurt oil butcher white cortex becomes flat, white and yellow cortex cortical cells rupture into a wavy outer concave. 4 rust diseases like rust-like disease began epidermal cell disease, the progressive development of small local lesions, epidermal parenchyma cells inside the skin lesions, lower oil gland lesions, severe yellow outer cortex cortex occurs even entire chunk of yellow disease, illness and health ministry has obvious boundaries lesion surrounding cells into flat round or polygonal, tightly around the diseased tissue neatly arranged longitudinally. 5. Susceptibility to diseases and illness is not easy citrus varieties 1) Fengjie navel orange susceptibility to diseases. Peel thick, rectangular or polygonal epidermal cells, arranged in neat, orderly, no intercellular space, outer cuticle. Cytoplasm and more small vacuoles. Parenchyma cells subcutaneously round to oval, gradually increases from outside to inside. Oil gland located in this layer, the oil and the oil gland cell spacing. White cortex loose. 2) Newhall navel orange peel is thin compared to Fengjie, epidermal cells are equilateral polygons, subcutaneous parenchyma cells were round, oil and oil gland cell spacing smaller than the Navel Orange. 3) Special thin tangerine peel oil cell sizes, the larger oil intercellular spaces, peel a single cell oil, white thin and loose. 4) citrus peel is thin, with double oil gland, the size varies, the upper oil cell density, cell gap is small, the lower oil gland sparse, large, two oil cells arranged alternately white and thin and loose.
|