Abbreviations: BC, body-cell. BN, body-cell nucleus. EC, egg cytoplasm . EN, egg nucleus. ER, endoplasmicr eticulum. EN, egg nucleus. FN, free nucleus. GC, genelative cell. GN, generative nucleus . Mt, mitochondrion. NE, nuclear envelope. Pt, plastid. SC, sperm cytoplasm. S, stach grain. SN, sperm nucleus. TC, tube cell. V, vacuole.Differential interference contrast micrograph(Fig: 1a);Phase contrast micrographs(Figs: 2a, 7, 9a, 10insert, a, 12a, 13a, 14a);DAPI-epifluorescence micrographs(Figs: 1b, 2b, 4a, b, c, 8, 9b, 10b, 12b, 13b, 14b);DiOC6(3)-epifluorescence micrograph(Fig. 12c);Transmission electron micrographs(Figs: 3, 5, 6a, b, 11a, b, 12d). Fig. 1a: A tube cell and a generative cell in the pollen. Bar=10μm. b: Arrow-heads indicate plastid and/or mitochondrial nucleoids in the generative cell. Distinguishment of plastids from mitochondria at this stage is difficult because of almost same size of their nucleoids and no accumulation of starch grain in plastids. Fig . 2a: A body-cell in the pollen tube. Granular appearance of plastids(arrow)becomes prominent due to accumulation of starch grains. Bar=10μm. b: Arrow-head indicates Pt nucleoid in the body-cell . Fig. 3. The matrix of spatula-shaped plastids in the body-cell is much electron dense and contains large starch grains. Thylakoids are poorly developed. Mitochondria in the body-cell are specifically sphedcal. Bar=1μm. Fig. 4a: Longitudinal section of the unfertilized egg cell shows a large vacuole in the middle of the egg and the egg nucleus on the micropylar side of the vacuole. Pt and/or Mt nucleoids(arrows)are found through the whole egg cytoplasm. Bar=25μm. b: Pt nucleoids(arrow-heads)are located near the egg nucleus. Bar=10μm. c: Pt and/or Mt nucleoids(arrow-heads)are located on the surface of the egg cell. Bar=1μm. Fig. 5. Rod-shaped plastids in the egg cell contain no starch grain and are covered by a sheath of ER(arrow-heads). Bar=1μm.
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