Influence of Arbuscular Mycorrhizae Strains on Phosphorous Nutrition, Rooting, and Growth of Tea (Camellia Sinensis) Clones
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Date
2021
Authors
Chelangat, Awa
Journal Title
Journal ISSN
Volume Title
Publisher
Kenyatta University
Abstract
Phosphorus is a critical nutrient for plant growth and makes up about 0.2% of dry matter
by weight. In soil, phosphates may be present in relatively large amounts, but much of
it is often made unavailable because of its very low solubility due to its complexes with
iron, aluminum, and calcium, resulting in very low concentrations (10 μm or less) in
the soil solution. Tea roots alone may be incapable of taking up phosphate ions that are
demineralized in soils with a basic pH. Mycelia of mycorrhizal fungus can, however,
access these phosphorus sources, and make them available to the plants they colonize.
Mycorrhizal fungi form relationships with over 95% of plant species. This therefore
formed the basis for the current study which determined the effect of different
mycorrhizal strains on infection rates, root initiation and establishment, phosphorus
uptake, shoot growth parameters in seedlings of different tea clones, treated with
different Mycorrhizal strains. In addition, the chemical and physical property changes
in soils treated with different mycorrhizal fungal strains was determined. The study was
laid out in a Randomized Complete Block Design (RCBD) with factorial arrangements.
The phosphorus treatment was a standard rate in all the plots while two clones of tea
(S15/10 and SC 12/28), and three mycorrhizal treatments (0 Kg/ha, 50 Kg/ha and 70
Kg/ha). The treatments were then replicated three times. Data were collected on initial
time of callusing, length of time for roots to start growing, chlorophyll content,
percentage success of shoot formation, length of roots, infection percentage of
Mycorrhizae, root biomass, soil phosphorus content, plant tissue phosphorus, and root
infection by mycorrhizal fungus (%). Application of mycorrhizae strains improved the
chlorophyll content in both tea clones with clone S 15/10 being the highest (489.8) at
50 kg Mycorrhizae ha-1
rate, while the highest callusing rate (73.3%) was also observed
on the same treatment. Significant differences (P≤0.05) were observed on the growth
parameters with the highest recorded under clone SC 12/28 where mycorrhizae strains
were incorporated. The soil pH was positively influenced by reducing the acidity
content significantly where mycorrhizae strains were introduced with the highest unit
change (1.3) being recorded on clone SC 12/28 at the 50 kg Mycorrhizae ha-1
rate. The
same treatment also significantly increased the soil total phosphorus level (2.3 g/kg)
compared to all other treatments with the least change observed on the control. The
introduction of mycorrhizae strains significantly increased the abundance of other
already existing mycorrhizae fungi population indicating a positive co-existence. The
intensity of AMF colonization in the root fragments was highest (86.7%) under clone
SC 15/10 at the rate of 50 kg Mycorrhizae ha-1 while the highest Arbuscule abundance
in mycorrhizal parts of root fragments (85.9%) was observed at the 70 kg Mycorrhizae
ha-1
rate on clone SC 15/10 with clone SC 12/28 at the rate of 50 kg Mycorrhizae ha-1
having 83.8%. The results show that mycorrhizal inoculation combined with
phosphorus application clearly reinforces growth, mineral content, and the chlorophyll
content.
Description
A Research Thesis Submitted in Partial Fulfillment of the Requirements for the Award of the Degree of Master of Science in Agronomy at The Kenyatta University, May,2021
Keywords
Arbuscular Mycorrhizae Strains, Phosphorous Nutrition, Rooting, Growth of Tea (Camellia Sinensis) Clones