• The Korean Journal of Mycology
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• v.26 no.1 s.84
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• pp.97-102
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• 1998

VA-mycorrhizal spores were collected from the 14 citurs orchards of different soil textures and locations in Cheju island. Five species and two kinds of spores were identified as based on the morphological characteristics of the spores; Acaulospora bireticulata, Glomus deserticola, G. geosporum, G. vesiculiferum, and Sclerocystis pachycaulis. Additionally, two kind spores of Acaulospora were also observed but difficult to be identified in this moment. Glomus deserticola and unidentified spores of Acaulospora (brown spores sized 90 to $125\;{\mu}m$ in diameter) were most frequently observed in the all soil specimens in Cheju, while the other kinds of spores were rarely observed in the soil of Cheju.

• Korean Journal of Environmental Agriculture
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• v.17 no.2
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• pp.182-188
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• 1998

The effect of arbuscular mycorrhizae(AM) on the growth of trifoliate orange seeding were investigated in volcanic ash soil. Trifoliate orange is used as a root stock of citrus in Cheju island. Seedings innoculated with AM fungi were grown for 16 weeks in pots of various levels of fertilizer. Growth characteristics and mineral nutrient contents were measured and spores of AM fungi colonized were identified. Seventy % of the replicsted pots of seedings were colonized by AM in the treatment of high level fertilizer and additional phosphate (40g of 21-17-17 complex fertilizer and 50g of fused phosphate added to 50L of soil). In treatments of low levels fertilizer or without fused phosphate addition, the pots colonized were less than 20 %. Colonization of trifoliate seedings with AM fungi greatly increased the growth of seedings. Shoot length and weight of shoot and root positively regressed on AM colonization ratio. AM colonization caused higher concentrations of P, Cu and Mg in plant, and the relations were significant at 5 % level. Contents of N and Zn in plants also tended to increase, while that of Ca to decrease, with increasing colonization ratio. Four species of AM fungi - Glomus deserticola, G. rubiforme, G. vesiculiferum and Acaulospora sp, - were found in the soil where roots of trifoliate orange as an innoculation materials were collected. All of the 4 species were found in the inoculated pot soils after the seedling growth, indicating that these species can be colonized in trifoliate orange roots.

• Korean Journal of Environmental Agriculture
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• v.17 no.2
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• pp.174-181
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• 1998

In four citrus grow of Satsuma mandarin (rootstock of trifoliate orange) including two grove of organical management and two groves of conventional management, spores of arbuscular mycorrhizal(AM) fungi were identified and seasonal changes in spore density in soils and AM colonization of citrus roots were investigated. AM colonization in weeds found in the groves were also examined. Three species of Glomus (G.deserticola, G. vesiculiferum, G. rubiforme ) and one unknown species of Acaulospora were observed in all of the groves. Annual mean density of AM fungal spores were in the range of 10,000${\sim}$40,000 per 100g soil with more spores in the organically-managed groves. The least spores were observed in December in all groves, and the most spores in April in the organically-managed groves while in February or April in the conventionally- managed. Annual mean AM colonization more 27% of citrus root were observed in the organically-managed with the high peaks in April and October and the minimum in August, while mean colonization less than 15% in the conventionally-managed with the peak in February and the minimum in different times depending on groves and years. AM colonization corresponded to a sigmoidal curve consisting of a laf phase during winter and a subsequent increase in spring, then succeeded by a maximum, and then a decrease at the end of vegetation. Fungal spore density and AM colonization showed a parallel pattern during the sample period. The seasonality appeared to be related more to the phenology of the plant than to the soil factors. Generally more spore density and AM colonization were found in organically managed groves. AM colonization was not correlated with available P and organic matter content in soil in this field investigation. Among sixteen weed species found in the groves, Astrogalus sinicus of Leguminosae, Portulaca oleracea of Portulacaceae showed high colonization in all groves and they can be considered as a source of inoculumn and host plants for propagation of AM fungi.