Introduction, growth and persistence in situ of orchid mycorrhizal fungi

2007 ◽  
Vol 55 (6) ◽  
pp. 665 ◽  
Author(s):  
Penelope S. Hollick ◽  
Jen A. McComb ◽  
Kingsley W. Dixon
Keyword(s):  
Seed Germination ◽  
Mycorrhizal Fungi ◽  
Mycorrhizal Fungus ◽  
Growing Season ◽  
Summer Drought ◽  
Orchid Species ◽  
The Third ◽  
Orchid Mycorrhizal Fungi ◽  
Germination And Growth

The introduction, growth and persistence of orchid mycorrhizal fungi in situ were studied by using a seed-baiting method. A mycorrhizal fungus from the carousel spider orchid, Caladenia arenicola (Hopper & A.P.Br.), was introduced to sites within an area from which the orchid and fungus were absent, adjacent to a natural population of C. arenicola. In the first growing season, the fungus grew up to 50 cm from its introduction point, usually persisted over the summer drought into the second season and even into the third season, stimulating germination and growth to tuber formation of the seeds in the baits. Watering the inoculated areas significantly increased seed germination. This suggests that it is possible to reintroduce the mycorrhizal fungi either before or together with seeds of orchid species needing re-establishment in an area.

scholarly journals Orchid Reintroduction Based on Seed Germination-Promoting Mycorrhizal Fungi Derived From Protocorms or Seedlings

2021 ◽  
Vol 12 ◽  
Author(s):  
Da-Ke Zhao ◽  
Marc-André Selosse ◽  
Limin Wu ◽  
Yan Luo ◽  
Shi-Cheng Shao ◽  
...  
Keyword(s):  
Seed Germination ◽  
Mycorrhizal Fungi ◽  
Essential Element ◽  
Ecological Factors ◽  
New Approach ◽  
Practical Procedure ◽  
In The Wild ◽  
Orchid Mycorrhizal Fungi ◽  
Ecological Specificity

Orchids are among the most endangered in the plant kingdom. Lack of endosperm in their seeds renders orchids to depend on nutrients provided by orchid mycorrhizal fungi (OMF) for seed germination and seedling formation in the wild. OMF that parasitize in germination seeds is an essential element for orchid seedling formation, which can also help orchid reintroduction. Considering the limitations of the previous orchid reintroduction technology based on seed germination-promoting OMF (sgOMF) sourced from orchid roots, an innovative approach is proposed here in which orchid seeds are directly co-sown with sgOMF carrying ecological specificity from protocorms/seedlings. Based on this principle, an integrative and practical procedure concerning related ecological factors is further raised for re-constructing long-term and self-sustained orchid populations. We believe that this new approach will benefit the reintroduction of endangered orchids in nature.

scholarly journals FEATURES OF BRASSICA RAPA'S GROWTH AND DEVELOPMENT, DEPENDING ON THE TERRITORY OF SOWING THE SEED

2019 ◽  
pp. 183-194
Author(s):  
Serhii Vdovenko
Keyword(s):  
Seed Germination ◽  
Soil Temperature ◽  
Growth And Development ◽  
Total Yield ◽  
Growing Season ◽  
Vegetation Period ◽  
Row Spacing ◽  
The Third ◽  
Golden Ball ◽  
And Control

In order to study the effect of the time of sowing seeds on the passage of morphogenesis and productivity of rapeseed, the scheme included experiments where the seeds were sown in I, II, III in April, I and II in May. The experiment used varieties of Golden Ball, Purpurleopop, Purpurov and Geisha, and control was the variant in which the seeds of the Golden Ball varieties were sown in the second decade of April with a row spacing of 45 cm. laboratory - to determine the total yield; statistical - to establish the reliability of the investigated factors. Seed germination analysis used in the experiment ranged from 78.9% to 81.1% on average. The highest indicator of seed germination was characterized by the Purpulepop variety, where the studied value was 83.2%, which was dominated by the seed germination of the control variant by 2.1%. In the early stages of sowing seeds, the period of seedling formation was shorter. Seeding of seeds in the first two decades of April on the surface of the soil was observed for 8 days. The short sprouting period was characterized by all varieties of turnips. As a result of sowing turnip seeds at a later date, namely in the third decade of April - the first and second decade of May and the setting of a higher soil temperature, the period of germination was extended and ranged from 8 to 10 days. By using the term of sowing seeds I-II decade of April, the short interphase period was characterized by Purpleupop and Purpurova varieties, where the specified period was only 22 days. The sowing of turnip seeds at a later date ensured the formation of an interphase period of "seedlings - leaf rosette" in 23-25 days except Purpulopop variety. The interphase period "leaf rosette - the beginning of rooting" and "the beginning of rooting - technical maturity" determined the benefits of early seeding, namely in the first decade of April on varieties Purpulopop and Purpurov.The short vegetation period was characterized by the Golden Ball plants for sowing seeds in the first and third decades of April and the first of May. During the specified seeding period the duration of the growing season was only 40 days. A longer vegetation period was characterized by plants of the Geisha variety for sowing seeds in the first two decades of April. As a result of the use of the researched elements of technology to grow turnips in open soil, the total yield varied from 11.0 t / ha to 24.0 t / ha. The most productive is the first sowing of rapeseed, where its value ranged from 20.6 t / ha to 22.7 t / ha. At the same time, when sowing seeds in the first decade of April, the yield of turnip varieties Purpulepop was the highest and was 22.7 t / ha, or the increase was 2.4 t / ha.

scholarly journals Effect of Direct Sowing and Stratification on Germination and Growth of Peach under Sub-tropical Climate of Uttar Pradesh

2021 ◽  
Author(s):  
K.K. Srivastava ◽  
P. Barman ◽  
D. Kumar
Keyword(s):  
Seed Germination ◽  
Uttar Pradesh ◽  
Subtropical Climate ◽  
Northern India ◽  
Planting Materials ◽  
Germination And Growth ◽  
Mature Seeds ◽  
Direct Sowing ◽  
Growth Of Seedlings

Background: Availability of quality planting materials is the major impediment in extension of cultivation of low chilling peach in northern plans. Plum suckers are mostly used as rootstocks for raising peach; however nematode infestation is a major problem. Seeds of all peach cultivars do not germinate under subtropical climate of plains of Northern India. Hence, an experiment was carried out at ICAR-CISH, Lucknow on seed germination and subsequent growth of seedlings of low chilling peaches.Methods: Fully mature seeds of peach cv. Florda Prince, Pant Peach 1 and Sharbati were collected during June. Some of the seeds were sown direct in-situ during 1st week of December and remaining seeds were sown in the field after 2 months of stratification in the refrigerator at 7-8°C.Result: Stratification had significant effect on seed germination and late matured peach cv. ‘Sharbati’ exhibited higher seed germination. Good linear seedling growth and maximum percentage of buddable seedlings was found in stratified sown seeds of ‘Sharbati’ peach. Thus the study indicated that harvesting of ‘Sharbati’ and ‘Pant Peach-1’ seeds can be done during June and pre-sown stratification is necessary for better germination and growth of seedlings under subtropical climate of Lucknow.

scholarly journals Understanding the distribution of three species of epiphytic orchids in temperate Australian rainforest by investigation of their host and fungal associates

Lankesteriana ◽  
2015 ◽  
Vol 7 (1-2) ◽  
Author(s):  
Kelli Gowland ◽  
Ulrike Mathesius ◽  
Mark Clements ◽  
Adrienne Nicotra
Keyword(s):  
Mycorrhizal Fungi ◽  
Local Environment ◽  
Direct Consequence ◽  
Environmental Constraints ◽  
Terrestrial Orchid ◽  
Orchid Species ◽  
Epiphytic Orchids ◽  
Carbon Transfer ◽  
Orchid Mycorrhizal Fungi ◽  
Fungal Associates

Understanding the environmental constraints that affect species distributions are critical to the mainte- nance of biodiversity. The abundance of epiphytic organisms, those that grow on another substrate, such as a tree or rock, is a direct consequence of the avail- ability and distribution of these substrates (Ackerman et al. 1989). In the case of epiphytic orchids it is also due to the presence of orchid mycorrhizal fungi (OMF). For an orchid, crucial to its germination and establishment, is its association with an OMF. The OMF provides a carbon source to the developing orchid embryo (Rasmussen 1995). Although recipro- cal carbon transfer has been demonstrated in mature plants of a green, terrestrial, orchid species, Goodyera repens (Cameron et al. 2006), it is generally believed that OMF receive no immediate benefit from their association with orchids. Therefore, it would appear intuitive that orchids would associate with all OMF available within their local environment and that they would actively seek this association. 

scholarly journals Availability of orchid mycorrhizal fungi on roadside trees in a tropical urban landscape

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Muhammad Izuddin ◽  
Amrita Srivathsan ◽  
Ai Lan Lee ◽  
Tim Wing Yam ◽  
Edward L. Webb
Keyword(s):  
Mycorrhizal Fungi ◽  
High Throughput Sequencing ◽  
Urban Expansion ◽  
Urban Trees ◽  
Tree Bark ◽  
Orchid Species ◽  
Epiphytic Orchids ◽  
Biophysical Factors ◽  
Natural Establishment ◽  
Orchid Mycorrhizal Fungi

AbstractUrban expansion threatens biodiversity worldwide, therefore urban spaces need to be amenable to biodiversity conservation. On trees in urban environments, natural colonisation and successful translocation of epiphytic orchids are necessary to enhance urban biodiversity, and depend on the availability of compatible orchid mycorrhizal fungi (OMF). However, the extent of OMF presence and distribution, as well as niche requirements for the OMF, remain poorly studied. To identify and quantify OMF on urban trees as well as assess their suitability for native epiphytic orchids, we conducted high-throughput sequencing on tree bark and orchid root samples. OMF were detected at 60% of the study sites on 16% of 270 bark samples (from stem, fork, and branch microsites within each tree). OMF presence and richness on bark samples were related to multiple biophysical factors; in general, humus presence and precipitation levels were positively predictive of OMF presence and richness. We found Ceratobasidiaceae- and Serendipitaceae-associated OMF both on bark and within roots. Orchid species also showed differing mycorrhizal specificity. Sites associated with fungal genera Ceratobasidium, Rhizoctonia, and Serendipita were considered suitable habitats for seven orchid species. The results suggest that urban trees support OMF and are therefore suitable for native orchid species; however, OMF availability are largely constrained by biophysical factors. To maximise the likelihood of translocation success and consequent natural establishment, we propose that (micro)sites are screened for compatible OMF prior to any intervention.

In situ symbiotic seed germination and propagation of terrestrial orchid seedlings for establishment at field sites

2006 ◽  
Vol 54 (4) ◽  
pp. 375 ◽  
Author(s):  
A. L. Batty ◽  
M. C. Brundrett ◽  
K. W. Dixon ◽  
K. Sivasithamparam
Keyword(s):  
Mycorrhizal Fungi ◽  
Seedling Survival ◽  
Natural Habitat ◽  
Survival Rates ◽  
Growing Season ◽  
Individual Species ◽  
Symbiotic Germination ◽  
Terrestrial Orchids ◽  
Eucalypt Woodland

The establishment of five species of temperate terrestrial orchids (Caladenia arenicola Hopper & A.P.Brown, Diuris magnifica D.L.Jones, D. micrantha D.L.Jones, Pterostylis sanginea D.LJones & M.A.Clem. and Thelymitra manginiorum ms) in natural habitat through in situ seed sowing, or by planting of seedlings and dormant tubers, was evaluated. Seed of the Western Australian temperate terrestrial taxa, Caladenia arenicola and Pterostylis sanguinea germinated best when sown into soil inoculated with mycorrhizal fungi at field sites but failed to develop the tubers necessary for surviving summer dormancy. However, seedling survival improved when actively growing symbiotic seedlings were transferred to natural habitat during the growing season. Caladenia arenicola and P. sanguinea seedlings survived the initial transfer to field sites but only P. sanguinea survived into the second growing season. Highest survival was obtained by translocating dormant tubers of C. arenicola and Diuris magnifica, with D. magnifica persisting at the site 5 years after translocation. However, outplanted C. arenicola survived for only 2 years. In another trial, where seedlings and dormant tubers of a rare orchid Thelymitra manginiorum were translocated into eucalypt woodland, 18% persisted after 5 years. The rare orchid D. micrantha exhibited the highest survival rates, with greater than 80% of tubers surviving 5 years after transfer of mature dormant tubers to field sites. This study highlights the benefit of using optimised methods for seedling production by symbiotic germination and nursery growth to produce advanced seedlings or dormant tubers to maximise the survival of translocated plants. It also demonstrates the need to consider different strategies when dealing with individual species.

scholarly journals Shallow Genome Sequencing for Phylogenomics of Mycorrhizal Fungi from Endangered Orchids

2019 ◽  
Author(s):  
Sarah A. Unruh ◽  
J. Chris Pires ◽  
Lawrence Zettler ◽  
Luigi Erba ◽  
Igor Grigoriev ◽  
...  
Keyword(s):  
Genome Sequencing ◽  
Mycorrhizal Fungi ◽  
Phylogenetic Trees ◽  
Species Boundaries ◽  
Internal Transcribed Spacer Region ◽  
Orchid Species ◽  
The World ◽  
Orchid Mycorrhizal Fungi ◽  
Current Species ◽  
Tulasnella Calospora

ABSTRACTMost plant species form symbioses with mycorrhizal fungi and this relationship is especially important for orchids. Fungi in the genera Tulasnella, Ceratobasidium, and Serendipita are critically important for orchid germination, growth and development. The goals of this study are to understand the phylogenetic relationships of mycorrhizal fungi and to improve the taxonomic resources for these groups. We identified 32 fungal isolates with the internal transcribed spacer region and used shallow genome sequencing to functionally annotate these isolates. We constructed phylogenetic trees from 408 orthologous nuclear genes for 50 taxa representing 14 genera, 11 families, and five orders in Agaricomycotina. While confirming relationships among the orders Cantharellales, Sebacinales, and Auriculariales, our results suggest novel relationships between families in the Cantharellales. Consistent with previous studies, we found the genera Ceratobasidium and Thanatephorus of Cerabotasidiaceae to not be monophyletic. Within the monophyletic genus Tulasnella, we found strong phylogenetic signals that suggest a potentially new species and a revision of current species boundaries (e.g. Tulasnella calospora); however it is premature to make taxonomic revisions without further sampling and morphological descriptions. There is low resolution of Serendipita isolates collected. More sampling is needed from areas around the world before making evolutionary-informed changes in taxonomy. Our study adds value to an important living collection of fungi isolated from endangered orchid species, but also informs future investigations of the evolution of orchid mycorrhizal fungi.

Distribution of the Orchid Mycorrhizal Fungus, Rhizoctonia solani, in Relation to Its Host, Pterostylis acuminata, in the Field

1995 ◽  
Vol 43 (6) ◽  
pp. 565 ◽  
Author(s):  
AJ Perkins ◽  
PA Mcgee
Keyword(s):  
Plant Pathology ◽  
Rhizoctonia Solani ◽  
Host Plant ◽  
Mycorrhizal Fungi ◽  
Mycorrhizal Fungus ◽  
The Other ◽  
Distribution Model ◽  
Orchid Mycorrhizal Fungi ◽  
Adult Plants

The plant pathology model was tested as an explanation of the distribution of orchid mycorrhizal fungi in the field. The mycorrhizal fungus, Rhizoctonia solani Kuhn AG 6, was isolated from adult plants and protocorms of Pterostylis acuminata R.Br. at a study site and from adult plants at five other locations in the Sydney region. In litter and trap seedlings, R. solani AG 6 was found within 50 cm of adult plants of the orchid P. acuminata and was more abundant close to the host plant. In the laboratory, protocorms of P. acuminata became infected with R. solani AG 6, but not with fungi isolated from the other orchids, P. concinna R.Br., P. ophioglossa R.Br. and Caladenia catenata (Smith) Druce, found at the site. It was concluded that the co-distribution model better explains the distribution of fungus and host in this case.

scholarly journals An expanded role for in vitro symbiotic seed germination as a conservation tool: two case studies in North America (Platanthera leucophaea and Epidendrum nocturnum)

Lankesteriana ◽  
2015 ◽  
Vol 7 (1-2) ◽  
Author(s):  
Emily Massey ◽  
Lawrence Zettler
Keyword(s):  
North America ◽  
Seed Germination ◽  
Case Studies ◽  
Mycorrhizal Fungi ◽  
Orchid Species ◽  
Symbiotic Germination ◽  
Symbiotic Seed Germination ◽  
Platanthera Leucophaea

Interest in using mycorrhizal fungi to cultivate orchids from seed in vitro (=symbiotic seed germina- tion) has intensified in recent years and this approach is now an important conservation tool worldwide. In North America, symbiotic germination has been attempted for a growing number of orchid species in peril as a means to acquire seedlings suitable for reintroduction.

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