scholarly journals Mycorrhizal Switching and the Role of Fungal Abundance in Seed Germination in a Fully Mycoheterotrophic Orchid, Gastrodia confusoides

2022 ◽  
Vol 12 ◽  
Author(s):  
Yuan-Yuan Li ◽  
Margaux Boeraeve ◽  
Yu-Hsiu Cho ◽  
Hans Jacquemyn ◽  
Yung-I Lee
Keyword(s):  
Seed Germination ◽  
Spatial Patterns ◽  
Seedling Establishment ◽  
Mycorrhizal Fungi ◽  
Forest Site ◽  
Bamboo Forest ◽  
Patterns Of Distribution ◽  
Fungal Abundance ◽  
Germination Experiments ◽  
Adult Plants

Mycorrhizal associations are essential for orchid germination and seedling establishment, and thus may constrain the distribution and abundance of orchids under natural conditions. Previous studies have shown that germination and seedling establishment in several orchids often decline with increasing distance from adult plants, resulting in non-random spatial patterns of seedling establishment. In contrast, individuals of the fully mycoheterotrophic orchid Gastrodia confusoides often tend to have random aboveground spatial patterns of distribution within bamboo forests. Since G. confusoides is parasitic on litter-decaying fungi, its random spatial patterns of distribution may be due to highly scattered patterns of litter-decaying fungi within bamboo forests. To test this hypothesis, we first identified the main mycorrhizal fungi associating with developing seeds and adult plants at a bamboo forest site in Taiwan using Miseq high-throughput DNA sequencing. Next, we combined seed germination experiments with quantitative PCR (qPCR) analyses to investigate to what extent the abundance of mycorrhizal fungi affected spatial patterns of seed germination. Our results show that seed germination and subsequent growth to an adult stage in G. confusoides required a distinct switch in mycorrhizal partners, in which protocorms associated with a single Mycena OTU, while adults mainly associated with an OTU from the genus Gymnopus. A strong, positive relationship was observed between germination and Mycena abundance in the litter, but not between germination and Gymnopus abundance. Fungal abundance was not significantly related to the distance from the adult plants, and consequently germination was also not significantly related to the distance from adult plants. Our results provide the first evidence that the abundance of litter-decaying fungi varies randomly within the bamboo forest and independently from G. confusoides adults.

scholarly journals Increasing fungal abundance in the substrate enhances seed germination in a fully mycoheterotrophic orchid

2021 ◽  
Author(s):  
Yuan-Yuan Li ◽  
Margaux Boeraeve ◽  
Yu-Hsiu Cho ◽  
Hans Jacquemyn ◽  
Yung-I Lee
Keyword(s):  
Seed Germination ◽  
Spatial Patterns ◽  
Seedling Establishment ◽  
Mycorrhizal Fungi ◽  
High Throughput Sequencing ◽  
Patterns Of Distribution ◽  
Mycorrhizal Associations ◽  
Fungal Abundance ◽  
Germination Experiments ◽  
Adult Plants

Mycorrhizal associations are essential for orchid germination and seedling establishment, and thus may constrain the distribution and abundance of orchids under natural conditions. Previous works have shown that germination and seedling establishment in several orchids often decline with increasing distance from adult plants, resulting in nonrandom spatial patterns of seedling establishment. In contrast, individuals of the fully mycoheterotrophic orchid Gastrodia confusoides often tend to have random spatial patterns of distribution within bamboo forests. Since G. confusoides is parasitic on litter-decaying fungi, its random spatial patterns of distribution may be due to highly scattered patterns of litter-decaying fungi within bamboo forests. To test this hypothesis, we first identified the main mycorrhizal fungi associating with developing seeds and adult plants using Miseq high-throughput sequencing. Next, we combined seed germination experiments with quantitative PCR (qPCR) analyses to investigate to what extent the abundance of mycorrhizal fungi affected spatial patterns of seed germination. Our results show that seed germination and subsequent growth to an adult stage in G. confusoides required a distinct switch in mycorrhizal partners, in which protocorms associated with a single Mycena fungus, while adults associated with a fungus from the genus Gymnopus. A strong, positive relationship was observed between germination and Mycena abundance in the litter, but not between germination and Gymnopus abundance. Fungal abundance was not significantly related to the distance from the adult plants, and consequently germination was also not significantly related to the distance from adult plants. Our results provide the first evidence that the spatial distribution and abundance of litter-decaying fungi are distributed randomly within the bamboo forest and independently from G. confusoides adults.

scholarly journals Germinación, dispersión y establecimiento de plántulas de Mimosa tenuiflora (Leguminosae) en México

2015 ◽  
pp. 543-554
Author(s):  
Sara L Camargo-Ricalde ◽  
Rosaura Grether
Keyword(s):  
Sulfuric Acid ◽  
Seed Germination ◽  
Seedling Establishment ◽  
Continuous Light ◽  
Seed Storage ◽  
Mother Plant ◽  
Constant Darkness ◽  
Seedling Characters ◽  
Germination Experiments ◽  
Mimosa Tenuiflora

Mimosa tenuiflora (Willd.) Poir. is an important natural resource in Mexico, due to its diverse uses. However, seed germination, dissemination and seedling establishment of this species had not been studied up to date. Fruits and seeds were collected in the State of Chiapas, Mexico (S. L. Camargo el al. 118, U AMIZ). Germinatíon experiments were carried out afier four years of seed storage; I 935 seeds were sown in Petri dishes containing moistened Wathman filter papero Optimum temperatures were determined in a gradíent 5-40 ° C, with continuous light for mechanically scarified and non scarified seeds. Three photoperiod experiments were made: a) continuous light, b) constant darkness and e) 12 hr lightJ12 hr darkness. Three germinate pretreatments were applied: al meehanical scarification, b) sulfuric acid scarification, el fire scarification and d) control. Three replicates of 15 seeds each were made for each variable and pretreatment. Standard deviations (S) were determined, a one-way analysis of variance ( ANOVAl and media comparison (Scheffé's test) were applied (p<0.05). Analysis of fruit and seed dissemination and seedling establishment was made qualitatively on the basis of field and laboratory observations; radius of dissemination of the fruits from the mother plant was measured; development of laboratory grown seedlings was followed during three months. Seeds germinated al 10- 3(J°C; however, the highest percentages of geCllÚnation were obtained at 200e (84.44%) and 25°C (95.55%); seeds are indistinctIy photoblastic and percentages of germination, afier the three germinate pretreatments, were: control (24.44- 35.55%), mechanical scarification (84.44-88.88%), sulfuric acid searificatÍon (73.33-91.11%) and fire scarification (0% l. Fruits and seeds are disseminated by the wind in a radius of 5-8 m fram the mother plant; rain carrÍes them from slopes to lower plains and human activities contri bu te to their dissemination. Growth of seedlings is fast; they develop a paripinnate protophyll and ten biparipinnate pronomophylls; the first nomophyll develops during the weeks 12 to 14. lt is concluded that optimum temperatures for seed germination of M. tenuiflora are 20 ° C and 2S o C; seeds are indistinctly photoblastic; percentage and rate of germination are highly increased by coat scarification. This species has certain advantages for its establishment in open areas, given by the abundant production of seeds, thelr small size, the rate of germination and Ihe fast growlh, as well as by its seedling characters: the tap root system, the hypocotyl-epicotyl axis woody at the base and, the eompound leaves with Iinear-oblong leaflets having changes in orientation in response to light. Our results confirm the invasive and typically secondary character of this species.

scholarly journals Characterization of the Heat-Stable Proteome During Seed Germination in Arabidopsis with Special Focus on LEA Proteins

2021 ◽  
Vol 22 (15) ◽  
pp. 8172
Author(s):  
Orarat Ginsawaeng ◽  
Michal Gorka ◽  
Alexander Erban ◽  
Carolin Heise ◽  
Franziska Brueckner ◽  
...  
Keyword(s):  
Seed Germination ◽  
Seedling Establishment ◽  
Intrinsically Disordered Proteins ◽  
Late Embryogenesis Abundant ◽  
Disordered Proteins ◽  
Similar Proportion ◽  
Special Focus ◽  
Lea Proteins ◽  
Intrinsically Disordered ◽  
Heat Stable

During seed germination, desiccation tolerance is lost in the radicle with progressing radicle protrusion and seedling establishment. This process is accompanied by comprehensive changes in the metabolome and proteome. Germination of Arabidopsis seeds was investigated over 72 h with special focus on the heat-stable proteome including late embryogenesis abundant (LEA) proteins together with changes in primary metabolites. Six metabolites in dry seeds known to be important for seed longevity decreased during germination and seedling establishment, while all other metabolites increased simultaneously with activation of growth and development. Thermo-stable proteins were associated with a multitude of biological processes. In the heat-stable proteome, a relatively similar proportion of fully ordered and fully intrinsically disordered proteins (IDP) was discovered. Highly disordered proteins were found to be associated with functional categories development, protein, RNA and stress. As expected, the majority of LEA proteins decreased during germination and seedling establishment. However, four germination-specific dehydrins were identified, not present in dry seeds. A network analysis of proteins, metabolites and amino acids generated during the course of germination revealed a highly connected LEA protein network.

scholarly journals Seed longevity of maize conserved under germplasm bank conditions for up to 60 years

2021 ◽  
Author(s):  
Filippo Guzzon ◽  
Maraeva Gianella ◽  
Jose Alejandro Velazquez Juarez ◽  
Cesar Sanchez Cano ◽  
Denise E Costich
Keyword(s):  
Seed Germination ◽  
Plant Genetic Resources ◽  
Seed Viability ◽  
Storage Conditions ◽  
Seed Longevity ◽  
Germplasm Bank ◽  
Significant Difference ◽  
Different Temperatures ◽  
Germination Experiments

Abstract Background and Aims The long-term conservation of seeds of plant genetic resources is of key importance for food security and preservation of agrobiodiversity. Nevertheless, there is scarce information available about seed longevity of many crops under germplasm bank conditions. Methods Through germination experiments as well as the analysis of historical monitoring data, we studied the decline in viability manifested by 1000 maize (Zea mays subsp. mays) seed accessions conserved for an average of 48 years at the CIMMYT germplasm bank, the largest maize seedbank in the world, under two cold storage conditions: an active (–3 °C; intended for seed distribution) and a base conservation chamber (–15 °C; for long-term conservation). Key Results Seed lots stored in the active chamber had a significantly lower and more variable seed germination, averaging 81.4 %, as compared with the seed lots conserved in the base chamber, averaging 92.1 %. The average seed viability detected in this study was higher in comparison with that found in other seed longevity studies on maize conserved under similar conditions. A significant difference was detected in seed germination and longevity estimates (e.g. p85 and p50) among accessions. Correlating seed longevity with seed traits and passport data, grain type showed the strongest correlation, with flint varieties being longer lived than floury and dent types. Conclusions The more rapid loss of seed viability detected in the active chamber suggests that the seed conservation approach, based on the storage of the same seed accessions in two chambers with different temperatures, might be counterproductive for overall long-term conservation and that base conditions should be applied in both. The significant differences detected in seed longevity among accessions underscores that different viability monitoring and regeneration intervals should be applied to groups of accessions showing different longevity profiles.

Allelopathic potential of Artemisia campestris ssp. caudata on Lake Huron sand dunes

1997 ◽  
Vol 75 (11) ◽  
pp. 1903-1912 ◽  
Author(s):  
Kyeong W. Yun ◽  
M. A. Maun
Keyword(s):  
Seed Germination ◽  
Seedling Growth ◽  
Mycorrhizal Fungi ◽  
Sand Dune ◽  
Sand Dunes ◽  
Dry Weight ◽  
Fungal Colonization ◽  
Test Species ◽  
Allelopathic Potential ◽  
Artemisia Campestris

Greenhouse studies were conducted to test allelopathic effects of Artemisia campestris ssp. caudata on seed germination and seedling growth of several sand-dune species and colonization by mycorrhizal fungi. The aqueous extracts of A. campestris showed no inhibitory effect on seed germination, seedling elongation, or dry-weight growth of plants at lower concentrations (10 and 50%), but 100% concentration of the extracts caused varying degrees of inhibition depending on the test species. The mixing of dry leaves of seedlings of A. campestris to the sand showed severe inhibition of Elymus canadensis seedlings. The percent germination of test species in soil from the rhizosphere of A. campestris was significantly lower than that of the control. The leaf area and dry weight were also lower but the differences were not significant. The aqueous extract inhibited mycorrhizal fungal colonization in roots of three sand-dune grasses. Key words: allelopathy, Artemisia campestris ssp. caudata, seed germination, seedling growth, mycorrhizal fungi.

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 Novel Approach to Study the Diversity of Soil Microbial Communities in Qatar

2020 ◽  
Author(s):  
Jane Oja ◽  
Sakeenah Adenan ◽  
Abdel-Fattah Talaat ◽  
Juha Alatalo
Keyword(s):  
Microbial Communities ◽  
High Throughput ◽  
Mycorrhizal Fungi ◽  
High Throughput Sequencing ◽  
Soil Microbial Communities ◽  
Arbuscular Mycorrhizal ◽  
Soil Microbial ◽  
Fungal Abundance ◽  
Novel Approach ◽  
Soil Climate

A broad diversity of microorganisms can be found in soil, where they are essential for nutrient cycling and energy transfer. Recent high-throughput sequencing methods have greatly advanced our knowledge about how soil, climate and vegetation variables structure the composition of microbial communities in many world regions. However, we are lacking information from several regions in the world, e.g. Middle-East. We have collected soil from 19 different habitat types for studying the diversity and composition of soil microbial communities (both fungi and bacteria) in Qatar and determining which edaphic parameters exert the strongest influences on these communities. Preliminary results indicate that in overall bacteria are more abundant in soil than fungi and few sites have notably higher abundance of these microbes. In addition, we have detected some soil patameters, which tend to have reduced the overall fungal abundance and enhanced the presence of arbuscular mycorrhizal fungi and N-fixing bacteria. More detailed information on the diversity and composition of soil microbial communities is expected from the high-throughput sequenced data.

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