Studies On Senescence Of Hyphae Of Cultivated Auricularia Auricula-Judae

Auricularia auricula-judae was one of the foremost cultivated edible fungi in China and was the main variety in Heilongjiang province. Cultivation of Auricularia auricula-judae (has)already become the backbone industry for enriching the people in some cities and counties. The senescence in hyphae was a problem frequently encountered in the process of production and seed production of Auricularia auricula-judae, which brought tremendous economic losses for Auricularia auricula-judae production. No references are found on senescence of hyphae in Auricularia auricula-judae at home and abroad, and there is not rationale of controlling senescence in hyphae. The paper, therefore, made a preliminary study on senescence of hyphae in Auricularia auricula-judae, to provide the scientific data for reveling the mechanism of senescence in hyphae of Auricularia auricula-judae.Micromorpholgical studies on senescence process of hyphae in cultivated Auricularia auricula-judae that indicated, in 30d after inoculation,the hyphae were uniform and well-knit; the cell wall was smooth. Under transmission electron microscope, the cells were intact, with abundant inclusions and all organelles were normal. In 60d part swelling hyphae were observed and the color of hyphae were darker. Under transmission electron microscope, the cell wall was unconsolidated, and the mitochondria and vacuole were swollen; nuclei were irregularly swollen, and nucleoli disappeared, and then granules and vesicles increased. Meanwhile, a few electron-dense granules appeared, which indicated the senescence of hyphae. In 90d membrane of part of the nuclei was broken, and a great amount of lipid granules, vesicles and electron-dense granules were observed. The cell wall was futher loose. In 120d lots of hyphae became fractured and the color was much daker. Under transmission electron microscope, collapsion of cell wall and disintegration of cytomembrane systeme were observed, and part of cell organelles, such as mitochondria, disappeared. In 150d most of hyphae were completely fractured and lost their shapes, and the cytomembrane and cell inclusions were almost disappeared, but part of collapsed cell walls were observed. It was indicated that, the senescence process of Auricularia auricula-judae hyphae was irreversible, which developed from individual to whole cells gradually.Studies on morphology and amount of mitochondrial in process of senescence in hyphae of Auricularia auricula-judae showed that mitochondrial were gradually swollen and deformation, even broken at last, with increased of cell age, and its amount also constantly decreased. It indicated that, the close relationship between the senescence of hyphae in Auricularia auricula-judae and the morphology and amount of mitochondrial. Studies on the physiological change of senescence process of Auricularia auricula-judae hyphae showed that there was positive correlation between the changes of malondialdehyde (MDA) content and the senescence degree of hyphae in Auricularia auricula-judae, have certain regularity, could as a reference index of senescence of Auricularia auricula-judae hyphae. Superoxide dismutase (SOD ) activity have dropped with increased of cell age, but more descend among 30d to 90d, and lesser descend among 90d to 150d, which unconspicuous regularity. Peroxidase (POD) activity instability in process of Auricularia auricula-judae hyphae, not obviously regularity. Catalase (CAT)activity whole task back with growth of hyphae, but it was restless, not striking regularity.Studies on effect of senescence of Auricularia auricula-judae hyphae by comparing the four kinds of inorganic salts showed that, KH2PO4 not only affected its growth rate, but also could restrain senescence. Moreover, adding KH2PO4 of 0.3% that its integrated effect was the most significant. MgSO4 has certain inhibitory action on the senescence and growth rate of Auricularia auricula-judae hyphae. but anti-aging effect not significant. NaCl although the anti-aging effect was significance, but seriously inhibit the growth of Auricularia auricula-judae hyphae was not conducive to producting. CaCO3 has stimulative growth of hyphae, but promoted the senescense process of hyphae, and sparse grewing(growth) and regeneration ability was poor.