Formation of Mycorrhizae by Jarrah (Eucalyptus marginata Donn ex Smith) in Litter and Soil

1984 ◽  
Vol 32 (5) ◽  
pp. 511 ◽  
Author(s):  
P Reddell ◽  
N Malajczuk
Keyword(s):  
Arbuscular Mycorrhizae ◽  
Prescribed Burning ◽  
Habitat Preferences ◽  
Fungal Growth ◽  
Nutrient Status ◽  
Nitrogen And Phosphorus ◽  
Eucalyptus Marginata ◽  
Factors Affecting ◽  
Main Site ◽  
Vesicular Arbuscular

In soils under forest conditions and on seedlings grown under glasshouse conditions jarrah mycorrhizae exhibited strong habitat preferences. Litter on the forest floor was the main site for the formation of the white and brown ectomycorrhizae, and removal of the litter layer by prescribed burning reduced by 90% the numbers of these two ectomycorrhizae. Black ectornycorrhizae were dominant in the mineral horizons of soil and were unaffected by the type of surface litter. In glasshouse experiments litter from different plant species significantly influenced formation of ectomycorrhizae by jarrah seedlings. Litter from Acacia pulchella R. Br. was favourable for formation of ectomycorrhizae but ectornycorrhizae were absent from Banksia grandis Willd. litter. Black ectomycorrhizae, Hysterangium- initiated ectomycorrhizae and vesicular arbuscular mycorrhizae formed on jarrah seedlings in the soils used in glasshouse studies. Addition of nitrogen and phosphorus to these soils influenced the relative abundance of mycorrhizae. It is postulated that inoculum levels, nutrient status of litter and soil and the presence of compounds inhibitory to fungal growth are critical in determining the abundance of mycorrhizae. Factors affecting formation of mycorrhizae by jarrah and the ecological implications of these results are discussed.

Site and Seasonal Effects on Susceptibility of Eucalyptus marginata to Phytophthora cinnamomi

1989 ◽  
Vol 37 (6) ◽  
pp. 481 ◽  
Author(s):  
JT Tippett ◽  
JF Mcgrath ◽  
TC Hill
Keyword(s):  
Phytophthora Cinnamomi ◽  
Water Status ◽  
Fungal Growth ◽  
Soil Nutrient ◽  
Nutrient Status ◽  
Seasonal Effects ◽  
Soluble Carbohydrate ◽  
Eucalyptus Marginata ◽  
Relative Water ◽  
Stem Lesions

Susceptibility of Eucalyptus marginata stems and roots to invasion by Phytophthora cinnamomi was compared at four sites in the northern jarrah forest and reasons for differences in tree susceptibility were sought. The sites were located in both the low (750 mm year -I ) and high (1 100 mm year -1) rainfall zones and differed in understorey composition and soil nutrient status. Stems were inoculated at monthly intervals between October 1983 and April 1984. Measurement of stem lesions induced by inoculation showed that rate of fungal growth in trees at all sites generally increased during the October-December (1983) period. During February and March (1984) there was a large difference in the susceptibility of stems and roots in low-rainfall zone sites compared with those in high-rainfall zone sites. Roots inoculated during February at three of the four sites showed the same relative susceptibilities as stems inoculated one week later. Mean relative water contents (RWC) of the phloem (inner bark) were used to compare the water status of the saplings at the four sites and the observed inhibition of the fungus in the sapling stems and roots at the driest sites, coincided with the months when phloem RWC values were at their lowest. Phloem was also sampled from pole-sized trees at the four sites and seasonal changes in RWC values, soluble carbohydrate concentrations and phenols were monitored for 12 months. Soluble carbohydrate concentrations in the phloem of some of the saplings inoculated at each site were also determined. Concentrations of carbohydrates and phenols did change seasonally and differed between sites but no evidence was found to suggest that they had a direct effect on fungal growth.

scholarly journals Vesicular Arbuscular Mycorrhiza Influences the Histo-Anatomic Characteristics of Vegetative Organs in Artemisia annua

2019 ◽  
Vol 2 (1) ◽  
pp. 5-11
Author(s):  
Erzsébet Domokos ◽  
Lilla Laura Csősz ◽  
Béla Darkó ◽  
László Jakab-Farkas
Keyword(s):  
Arbuscular Mycorrhizae ◽  
Artemisia Annua ◽  
Nutrient Status ◽  
Glandular Hair ◽  
Hair Density ◽  
Vegetative Organs ◽  
Vesicular Arbuscular Mycorrhizae ◽  
Leaf Chlorophyll ◽  
Vesicular Arbuscular ◽  
Stimulate Plant Growth

Abstract Recent studies have shown that vesicular-arbuscular mycorrhizae stimulate plant growth in case of Artemisia annua plants. According to these studies mycorrhization can enhance plant height and biomasses, shoot branching and inter-nodal length, foliar glandular hair density, and nutrient status of shoots and leafs. Contradictory data were obtained in case of leaf chlorophyll content and photosynthetic rate. The effects of vesicular-arbuscular mycorrhizae on roots, shoots and leafs anatomy of A. annua have not been studied yet. The aim of this paper was to compare the microscopic characteristics of the vegetative organs from the Artemisia annua plants treated with vesicular-arbuscular mycorrhizae, with those from the control plants. Rhizophagus irregularis influenced the development of vascular tissues in root and stem of Artemisia plants by increasing their surface in the organs. Mycorrhization also reduced the percentage of lignification in the cortex of the root, increased the percentage of palisade parenchyma in leaf and had a positive effect on foliar glandular hair density. Further investigations are necessary to find out the role of these histo-anatomic alterations in the growth and development of Artemisia plants.

Response ofBradyrhizobium-Inoculated Soyabean and Lablab Bean to Inoculation With Vesicular-Arbuscular Mycorrhizae

1992 ◽  
Vol 28 (4) ◽  
pp. 399-408 ◽  
Author(s):  
A. A. Mahdi ◽  
I. M. A. Atabani
Keyword(s):  
Dry Matter ◽  
Glomus Mosseae ◽  
Arbuscular Mycorrhizae ◽  
Dry Matter Yield ◽  
Triple Superphosphate ◽  
Nitrogen And Phosphorus ◽  
Field Inoculation ◽  
Plant Nitrogen ◽  
Vesicular Arbuscular ◽  
Tissue Nitrogen

SUMMARYPot and field investigations were conducted to study the effects of vesicular-arbuscular mycorrhizal (VAM) inoculation and triple superphosphate fertilization on nodulation, dry matter yield and tissue nitrogen and phosphorus contents ofBradyrhizobium-inoculated soya-bean and lablab bean in the Sudan.Inoculation of both crops with the VAM fungusGlomus mosseaein clay and sandy soils in pots increased nodulation, dry matter yield and tissue nitrogen and phosphorus contents more than triple superphosphate fertilizer, but even greater responses were obtained fromG. mosseaecombined with fertilizer. Crop responses in the two soils were similar, despite the large differences in soil physico-chemical properties.In the field, inoculation of both crops with any of four VAM fungi enhanced nodulation, dry matter yield and plant nitrogen and phosphorus contents more than did triple superphosphate.Gigaspora margaritaandGlomus mosseaewere superior toGigaspora calosporaandAcaulosporaspecies and resulted in more extensive root infection, especially in soyabean.

Factors affecting post-fire seedling establishment of selected mallee understorey species

2000 ◽  
Vol 48 (1) ◽  
pp. 59 ◽  
Author(s):  
J. S. Cohn ◽  
R. A. Bradstock
Keyword(s):  
Large Scale ◽  
Prescribed Burning ◽  
New South ◽  
Eucalyptus Species ◽  
Factors Affecting ◽  
Acacia Species ◽  
Introduced Herbivores ◽  
South Wales ◽  
Rabbit Grazing ◽  
Seedling Germination

Factors affecting the survival of post-fire germinants in mallee communities, in central western New South Wales, were examined. Experiments compared the relative effects of native and introduced herbivores (kangaroos, goats, rabbits), after small- and large-scale fires (20–50 and > 10 000 ha, respectively), with particular emphasis on edge effects, seedling clustering, topography and eucalypt canopy presence. The experiments (1985–1997) focused on common understorey species Acacia rigens Cunn. ex Don, A. wilhelmiana F.Muell. and Triodia scariosa N.T.Burb. subsp. scariosa, in mallee dominated by Eucalyptus species. Following a large fire (1985), high spring rainfall and rabbit grazing on A. rigens only, survival of Acacia species and T. scariosa remained relatively high 4 years later (60–70%). After small burns (1987, 1988), low spring rainfall and grazing by rabbits and kangaroos, survival of Acacia species declined to between 0 and 30% of the germinants by the second summer. In most cases, local extinction had occurred within 8 years. After small burns (1988, 1989) and low spring rainfall, the survival of T. scariosa declined to between 0 and 35% of germinants by the second summer (effect of grazing unknown). No consistent effect of edge, topography and eucalypt canopy was found. Survival of clustered Acacia seedlings was between 10 and 20% lower than unclustered seedlings. Given the high frequency of low rainfall and its interaction with grazing, prescribed burning of mallee for wildfire control and nature conservation may require the local elimination of rabbits and a reduction in kangaroo numbers, especially in the first spring and summer following seedling germination.

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