Orchid mycorrhizae (botany) mycorrhizaei

It's relationship between fungi and orchid. It's called symbiotic relation. The type of fungi is endomycorrhizae. fungi is help in take phosphorus and nitrogen in soil and orchid gave a nutrition in fungi.

1. Orchid Mycorrhizae Presented by :- Parekh Nidhi Jagdishbhai Roll No :- 12 College :- M. N college, Visnagar

2. content Mycorrhizae definition Types Orchid Mycorrhizae Role in seed germination seed germination Factors affecting seed germination Nutrients exchange between orchid and Mycorrhizal fungi

3. Mycorrhizae J Mycorrhiza are a symbiotic association between plant roots and fungi. There major role is to enhance nutrient and water uptake by the host plant by exploiting a large volume of soil then roots alone can do. The plant provides the fungus with carbohydrates formed from photosynthesis.

4. Types :- 1) Endomycorrhizae 2) Ectomycorrhizae

5. Orchid mycorrhizae Micorrhiza in orchid species are highly important throughout their whole life including germination and further development. The early stage of orchid reproduction and development, especially the germination of orchid seed, are highly influenced by the relationship with their appropriate mycorrhizal fungi as well as their surrounding environments.

6. Fungi forming orchid mycorrhizae The man group of fungi in habiting orchid roots is basidiomycetes, this fungi come from range of taxa including Pathogenic Rhizoctonia . Sebacina , Tulasnella Russula species. Though rare in orchids, Ascomycete association have been documented in serveral orchid species.

7. Role in seed germination The most important contribution of mycorrhizal fungi to orchid is supplying nutrition for growth and development. Orchid seeds under natural conditions are unable to germinate without a supply of C, mineral nutrients as well as vitamins from their symbiotic partners. Additionally, Mycorrhizal fungi also contribute to supplying and retaining water for orchid species during germination. This is also a highly essential roll of mycorrhizal fungi because orchid seeds commonly have a hydrophobic testa to avoid imbibition in unfavourable environments.

8. Seed germination Under the coexistence with mycorrhizal fungi, orchid seed can germinate and develop into unique seedling structure called protocorm that consist of parenchyma cells. Then for the development of the protocorm into plant is also supported by their mycorrhizal fungi. In protocorm of orchid, the entered fungal hyphae from coiled complex called Pelotons . Orchid can obtain nutrients by digesting them.

9. Factors affecting Seed germination Many environmental factor including abiotic factors, such as a light Soil structure Moisture And biotic factors, such as a microorganism Are required to be considered for the successful germination of orchid seeds and further development This factor affect not only orchid seeds but also the success in symbiotic association between orchid and micorrhizal fungi. FOR EXAMPLE :- It has been shown that organ development of symbiotic orchid seedlings and development of photosynthetic structure are affected by light intensity, whereas development of micro tropic tissues suppress the by light.

10. Nutrient exchange Mycorrhizal symbiosis are important for the growth and survival of many plant species and a responsible for up to 80% of nitrogen and phosphorus uptake by plants. In general, o mutualistic relationship for nutrient exchange is established between plant and micorrhizal fungi in which plant provide photosynthetically fixed C to the symbiotic fungi and the y benefit from fungi with regard to absorption of mineral nutrient such as N and P. Compared to the other types of mycorrhizas, the orchid fungus symbiosis is considered to be unique since the nutrient movement is not bi-directional in the early development stages and even in adults of some orchid species. As the orchid Seeds are Very tiny with very little storage, colonization buy fungi is required for their germination and/or early protocorm development.

11. Therefore, the mycorrhizal fungi Were throughout to provide both mineral nutrient and carbon to the non photosynthetic orchid seedlings and to receive no reward. However , similar to all other mycorrhizal symbioses, the mycorrhizal fungi receive C as a reward for exchanging mineral nutrient after orchid develop green leaves for photosynthesis. Although the majority of orchid are autotrophic with photosynthetic ability, more than 100 species are my coheterotropic which are completely achlorophylls and nutritionally dependent on their symbiotic fungi throughout the whole life cycle.