The taxonomic composition at phylum and class levels of
turmeric rhizosphere fungal communities in all investigated regimes
appeared relatively uniformed. Accordingly, OTUs of Ascomycota
were prevalent; especially in soil samples of regime N150 with
74.16±9.06% of total identified OTUs. Besides, the proportion of
OTUs belonging to Basidiomycota tended to increase as the raising
amount of N fertilizer. In addition, several fungal genera such as
Zygomycota, Rozellomycota and Blastocladiomycota were found at
higher rates in soil samples of L group (N0 and N500). However,
statistical analysis showed no significant differences in abundance of
Basidiomycota, Zygomycota, Rozellomycota and
Blastocladiomycota between H and L groups (p>0.05).
27 trang |
Chia sẻ: honganh20 | Ngày: 07/03/2022 | Lượt xem: 321 | Lượt tải: 0
Bạn đang xem trước 20 trang tài liệu Study on rhizosphere microbial communities of medicinal plant curcuma longa l. to enhance turmeric yield and quality, để xem tài liệu hoàn chỉnh bạn click vào nút DOWNLOAD ở trên
iotechnologically potential microorganisms and
eventually to a sustainable production of the novel bioactive
metabolites.
CHAPTER 2. MATERIALS AND METHODS
2.1. Materials
2.1.1. Turmeric cultivar and crop
This study was conducted at a turmeric growing area located
in Dai-Tap commune, Khoai-Chau district of Hung-Yen province
5
(20°47′35″ N, 105°56′42″ E) using local seed rhizome of Curcuma
longa.
2.1.2. Chemicals, oligonucleotides, media and microorganisms
2.2. Methods
2.2.1. Soil sampling and determination of soil physiochemical
parameters
Sampling: Soil samples were taken randomly from turmeric rhizome
soil (10-15 cm depth from the top soil). Samples of each plot were
then bulked, homogenized and grouped together to one sample set,
followed by storing at 4
o
C prior to DNA extraction.
Determination of soil physiochemical parameters
2.2.2. Study on impacts of chemical N fertilizing rates to turmeric
productivity
Experimental design
Field study was conducted from April to December 2016 and
replicated in 2017. The experiment was laid out in a randomized
complete block design and three replicates. Experimental units
consist of 10 m
2
plots each with one fertilizer regime, resulting in a
total of 16 plots in a total area of 160 m
2
. The treatments were four N
fertilizer rates (0, 150, 350 and 500 kgN.ha
-1
.y
-1
) incorporated with K
and P fertilizers (400:200 kg.ha
-1
.y
-1
), resulting in 5 fertilizer
regimes: N0, N150, N350 and N500, respectively. Soil samples were
taken randomly from turmeric rhizome soil (10-15 cm depth from the
top soil) at five points of each plot following a W-pattern (Thomas
1985) [115].
Plant growth and productivity parameters: Plant height (cm);
Number of leaves/plant; Fresh rhizome yield (kg/ha); Fresh rhizome
yield/dry rhizome yield ratio (%); Curcuminoids content.
6
After harvesting, turmeric rhizomes were sliced and dried.
Curcuminoids from turmeric samples were extracted by an
ultrasound assisted extraction method using ethanol/water (70:30,
v/v) solvent as described by Mandal et al. (2009) [116]. The
quantification of curcuminoids content was performed using high
performance liquid chromatography (HPLC) following the method
of Jayaprakasha et al. (2006) [46].
2.2.3. Study on impacts of N fertilizing rates to diversity of turmeric
microbial community
Total DNA extraction from turmeric rhizosphere soil samples
Total DNAs were extracted by using PowerSoil
®
DNA
Isolation kit (Mo Bio Laboratories, Qiagen, USA) and quantified by
Nano drop (Nanodrop 2000c, Thermo Fisher Scientific, USA) in
combination with electrophoresis in gel agarose 1% and stored at
-20
o
C.
Metagenome amplicons sequencing
Sequencing libraries were prepared from the PCR products
using TruSeq® DNA PCR-Free Sample Preparation Kit (Illumina,
USA). The quality of libraries was assessed on Bioanalyzer 2100
system (Agilent, USA) before sequencing on Illumina HiSeq 2500
platform (Illumina, USA).
Bioinformatic analysis
The metagenome databases were analyzed following Qiime2
analyzing pipeline (https://qiime2.org/) [118]. The analysis process
comprises 3 main steps, namely (i) Preprocessing; (ii) Taxonomy;
and (iii) Diversity analysis and visualization.
Preprocessing: Using quality control tools of Qiime (V1.7.0,
[146] and
7
UCHIME algorithm (
manual/uchime_algo.html) [148].
Taxonomy: Using Uparse software (Uparse v7.0.1001,
[149], Unite database
(https://unite.ut.ee/) [150] and Silva database
(https://www.arb-silva.de/) [151].
Diversity analysis and visualization
Microbial diversity indices
Determination of Shannon-Weaver (H), Simpson (D1),
Chao1 and ACE indices was performed by Qiime 2.
PCA & PCoA
Principle Component Analysis (PCA) and Principle
Coordinate Analysis (PCoA) were conducted by applying R software
(v 3.1.2, R Core Team 2014).
Rarefaction curve
Statistical Analysis:
Using ANOVA followed by Tukey’s Honest Significant
Difference (HSD) post hoc tests.
2.2.4. Isolation of PGPR and plant growth promoting assays
Isolation of PGPR strains with phosphate solubilizing ability:
Rhizosphere soil samples were diluted and spread on IPA agar plates
for bacterial colonies formation [138].
IAA producing assay: IAA assay was conducted following
Salkowski’s method [139].
Antagonism to test pathogenic microorganisms: Agar diffusion test
as described by Ahmad & cs. (1998) [140].
Determination of biochemical and physiological characteristics:
According to Bergey’s Manual of Systematic Bacteriology [141,
142].
8
Phylogenetic identification using partial 16S rDNA gene sequences:
The partial 16S rDNA gene sequences of bacterial isolates
were amplified using PCR with primers Pr16F-Pr16R and compared
to published sequence in GenBank using BLASTn tool, and analyzed
by BioEdit 7.0 [144] and MEGA X [145] [146] softwares.
2.2.5. Isolation and characterization of AMF
Isolation of AMF spores from turmeric rhizophere soil samples:
AMF spores from rhizosphere soil samples were isolated using wet
sieving and decanting method (Gerdemann, Nicolson, 1963) [147].
Partial 18S rRNA gene amplification and phylogenetic inference
Fragments of partial small subunit (SSU) rRNA gene from
extracted genomic DNA samples were amplified using universal
eukaryotic forward primer NS31 and reverse primers mixture AM
containing AM1, AM2 and AM3 [148, 149, 150] to amplify AM
fungal SSU sequences. Clones from each sample were tested for the
PCR amplicons and sequenced on an ABI PRISM® 3100 Avant
Genetic Analyzer (Applied Biosystems, USA) sequencer.
2.2.6. Preparation of biopfertilizer for turmeric and case study on
turmeric productivity
Preparation of biofertilizer from isolated turmeric rhizosphere
effective microbial strains
Safety test: Safety tests for microbial strains were conducted
in BALB/c mice as described by Carter et al. [151].
AMF
AMF spores were preserved and inoculated in pot cultures of
Plantago lanceolata (supplied by Institute of Seed and
Biotechnology - Vietnam Academy of Forest Science).
9
PGPR fermentation and biomass harvesting
AMF spores harvesting
Preparation of PGPR and AMF inocula: Biomass mixture
of PGPR strains and spore mixture of AMFs were blended in
1:1 ratio (w/w).
Case study on the effect of biofertilizer in turmeric plant
Experimental design
Experiment was conducted at the Ministry of Health’s
Botanical garden in Thanhtri, Hanoi from May to November 2018.
The 12 m
2
units were designed in a total area of 30 m
2
belonging to 2
experiment groups: (i) Microbial inocula applied turmeric
(symbolized as CP), and (ii) Control (symbolized as DC).
Determination of growth and productivity parameters
The growth parameters are monitored periodically.
Productivity was determined based on fresh biomass at the end of the
experiment.
III. RESULTS AND DISCUSSION
3.1. Investigation of relationship between nitrogen fertilizer
regimes and turmeric productivity
Environmental parameters of turmeric farming site
Initial edaphic conditions prior to experimental plotting were
determined by standard methods according to TCVN 7373:2004,
7374:2004 and 7375:2004. Results showed that the parameters
corresponded sandy loam characteristics with relatively good soil
quality.
10
Turmeric productivity and curcuminoids content in response to N
fertilizer rates
Turmeric productivity of different fertilizing regimes was
determined in terms of fresh rhizome yield and curcuminoids
content. The averaged fresh rhizome yield after harvesting was
recorded in form of mean±SD as following: 21038±5013 kg.ha
-1
.y
-1
(N0), 27003±4703 kg.ha
-1
.y
-1
(N150), 30902±1642 kg.ha
-1
.y
-1
(N350); 20578±2306 kg.ha
-1
.y
-1
(N500).
From these results, it is obvious that obtained turmeric yield
in regimes N0 and N500 was lower than in N150 and N350. Most
likely, either excessive or inadequate nitrogen inputs had negative
effect on turmeric plant’s vigor and nutrient accumulation. Farming
regimes with nitrogen fertilization levels ranging from 150 to 350
kg.ha
-1
were considered optimal for fresh rhizome yield of turmeric.
Figure 3. 2. Averaged fresh turmeric rhizome yield and
curcuminoids content in experimental regimes.
Curcuminoids content in response to N fertilizer rates
The averaged curcuminoids content of each farming regime
was calculated from available data after determination of dry
rhizome weight and analysis of rhizome extracts. Results revealed
11
the highest curcuminoids yield in the experimental plots of N150
farming regime. Figure 3.2 summarizes averaged turmeric yield and
curcuminoids content in relation to N fertilizer inputs. As illustrated
in the figure, with N fertilizers ranging from 150 to 350 kg.ha
-1
.y
-1
,
the turmeric yield and curcuminoid content were both recorded at
higher levels than in either non-fertilized N0 or over- fertilized
N500.
Effects of N, P and K chemical fertilizers on turmeric yield
and curcumin content have been intensively investigated in various
geoecological areas of the global, but research results were
inconsistent. The present results have confirmed the hypothesis of N
fertilizer’s effect on yield and curcumin content in C. longa. On the
other hand, the research has supported fundamental data for
designation of appropriated fertilizing practices for turmeric plant in
Vietnam.
3.2. Investigation of effective microbial groups in turmeric
rhizosphere
The investigation of effective microbial groups in turmeric
rhizosphere was oriented by published research results and reviews
concerning symbiotic microorganisms of C. longa. Accordingly, we
focused on two main rhizosphere microbial groups, namely growth
promoting rhizobacteria (PGPR) and arbuscular mycorrhizal fungi
(AMF), thereby aiming to screening for a collection of microbial
candidates for preparation of effective biofertilizer.
3.2.1. Investigation of plant growth promoting rhizobacteria
(PGPR) in turmeric rhizosphere
3.2.1.1. Isolation and screening of PGPR
The isolation of PGPR strains from turmeric rhizosphere was
performed with following criteria: (i) Dissolve inorganic phosphate;
12
(ii) Production of indole aceteic acid (IAA); (iii) Nitrogen fixation
ability and (iv) Antagonism to test pathogenic microorganisms.
Screening results for PGPR strains from turmeric rhizosphere soil
samples are shown in Table 3.6.
Table 3. 6. Phosphate solubilizing ability, development in nitrogen-
free medium and IAA production of PGPR strains.
N
o.
Strain
Phosphate
solubilizing
ability (D-d, mm)
Development in
nitrogen-free
medium
IAA
production
(ppm)
1 PGP-V2 3 + 24.80±2.21
2 PGP-V4 5 - 9.66±1.72
3 PGP-V5 3 + 67.51±2.11
4 PGP-V15 5 + 35.47±3.05
5 PGP-V18 3 + 26.82±1.46
6 PGP-V20 4 + 77.87±2.78
7 PGP-V21 6 + 63.11±2.09
8 PGP-V22 4 + 11.61±1.85
9 PGP-V24 4 - 45.81±2.89
* D: diameter of halos around bacterial colony; d: diameter of
bacterial colony on agar plate.
The indirect plant growth promoting effect of PGPR strains
was evaluated basing on in vitro antagonism to plant pathogenic
fungi Aspegillus niger and Fusarium oxysporum on agar plates. The
result revealed inhibitory activity against both tested fungi A. niger
and F. oxysporum of Bacillus sp. PGP-V21 with halo diameters of 9
and 3 mm, respectively.
PGP-V5, PGP-V20 and PGP-V21 emerged as promising
effective bacteria with typical PGP characteristics in terms of
relatively potent P solubility, nitrogen fixation and IAA production.
The bacterial strains were taxonomical characterized by determining
morphological and physio-biochemical characteristics, in
combination to partial 16S rRNA gene sequences analysis.
3.2.1.2. Morphological and taxonomical characteristics
13
Figure 3.3. Phylogenetic tree of PGP-V5, PGP-V20, PGP-V21 and
published bacterial species basing on parial 16S rRNA gene sequences
(Maximum likelihood method, 100 bootstrap replicates, consensus tree).
Methylobacterium populi AP014809 was the out group.
Morphological characteristics of bacterial colonies on agar
plates containing LB medium and under microscope (magnification
x1000) were observed. The morphological, physiological and
biochemical features of the strains were compared with Bergey's
classification key [141] [142]. Based on published sequences in
GenBank and subsequent sequence analysis, a classification tree of
strains PGP-V5, PGP-V20 and PGP-V21 has been constructed
(Figure 3.3). As a result, the PGP bacterial strains were determined
as Bacillus sp. PGP-V5, Enterobacter sp. PGP-V20 and Bacillus sp.
PGP-V21.
14
In conclusion, four PGPR strains were isolated and
biologically characterized from rhizosphere of turmeric plant in the
course of the investigation.
3.2.2. Investigation of arbuscular mycorrhizal fungi (AMF) in
turmeric rhizosphere
3.2.2.1. Isolation of AMF
Besides PGPR, AMF has been intensively mentioned as
effective symbionts of turmeric rhizosphere in earlier reports,
especially those in Indian turmeric varieties [160, 161], however,
there has not been any similar research hitherto on the indigenous
turmeric sample of Vietnam.
By wet decanting and filtrating [147], the presence of AMF
spores in rhizosphere soil samples of turmeric in the study area at
three different investigated periods (2, 5 and 8 months after planting)
was determined. The results showed that investigated AMF spore
numbers increased from 23.6±5.5 spores/100 g soil two months after
planting to 66.5±7.5 spores/100 g at 8 months old turmeric.
3.2.2.2. Morphological and taxonomical characterization of AMF
strains isolated from turmeric rhizosphere
Depending on AMF’s spores’ microscopic characteristics,
including spore sizes, shapes and color, three most popular
morphological groups were selected to preserve and culture, namely
AM-N1, AM-N2 and AM-N3. The AMF groups were identified to
belong to three distinct fungal groups of genus Glomus.
15
Figure 3. 5. Phylogenetic tree of AM-N1, AM-N2, AM-N3 and
published fungal species basing on parial 18S rRNA gene sequences
(Maximum likelihood method, 100 bootstrap replicates). Gigaspora
margarita BEG152 was the out group.
By analyzing partial 18S gene sequences after DNA isolation
and Nested-PCR amplification, the AMF strains were taxonomically
identified. The results unraveled relationship between selected AMF
strains and published species on GenBank, most of which were
found to belong to the genus Glomus. The phylogenetic tree of
strains AM-N1, AM-N2 and AM-N3 was constructed and depicted in
Figure 3.5.
Taken these above results together, the isolated AMF strains
from turmeric rhizosphere samples were identified as Glomus sp.
AM-N1, Glomus intraradices AM-N2 and Glomus mosseae AM-N3.
16
3.3. Impact of N fertilizer rates to turmeric rhizosphere
microbial communities
3.3.1. Abundance of turmeric rhizosphere bacterial communities
under varied N fertilizer rates
3.3.1.1. Diversity indices of turmeric rhizosphere bacterial
communities
Achieved bacterial OTUs from turmeric rhizosphere samples
of four fertilization regimes (N0, N150, N350 and N500) were
analyzed using bioinformatic softwares and Unite database. The
average number of fungal species in samples of the N0, N150, N350
and N500 regimes were 3105, 2286, 2760 and 2843, respectively
(Table 3.16).
Table 3. 1. 16S amplicons metagenome sequencing data and
analyzed diversity indices.
Sample name N0 (n=3) N150 (n=3) N350 (n=3) N500 (n=3)
Averaged species
number
3105 2286 2760 2843
Simpson index 0.703 ± 0.11
0.665 ±
0.08
0.712 ± 0.10 0.733 ± 0.12
ACE index 2012 ± 354 1893 ± 196 2068 ± 244 1992 ± 259
Chao1 index 1765 ± 103 1994 ± 262 1549 ± 306 1266 ± 220
Shannon-Weaver 3.77 ± 0.50 2.95 ± 0.25 4.04 ± 0.71 3.73 ± 0.56
Coordinate analysis (PCoA) based on biodiversity indices
(Figure 3.10) allowed a separation of group L (blue) from group H
(red). In other words, there was a difference between the bacterial
communities from the high yielding group H (regimes N150 and
N350) and the low yields L (regimes N0, N500).
3.3.1.2. Taxonomic composition of turmeric rhizosphere bacterial
communities
17
The analysis results showed relatively uniform compositions
of turmeric rhizosphere bacterial communities at phylum and class
levels of groups L and H. Accordingly, predominant proportions of
Alpha-proteobacteria belonging to Proteobacteria were observed in
both groups, accounting for over 40% of the total identified OTUs (p
<0.05). Similarly, class Gemm-1 of Gemmatimonadetes appeared
most analyzed samples with over 5% of total OTUs (p<0.05). The
analysed 16S amplicons metagenome data suggested on one hand an
indigenous soil bacterial communities structure in the research area,
on the other hand a specific composition of rhizosphere bacterial
communities of turmeric plant.
Noteworthy, the Gram negative bacteria of Proteobacteria,
whose representers such as free-living nitrogen-fixing and poor
nutritional conditions adapters [171], were abundantly found in
rhizosphere samples of regime N0. Most likely, the N nutritional
poverty condition in regime N0 inhibited other microbial groups,
promoting competitive advantage and increased distribution of
Proteobacteria, especially those belong to Alphaproteobacteria.
In general, after analyzing NGS sequencing data of ITS and
16S metagenome amplicons of C. longa rhizosphere samples, a total
of 4776 OTUs of bacteria and 1760 OTUs of fungi were obtained.
Bacterial OTUs are identified mainly to belong to Proteobacteria
(40-60%), Firmicutes (5-20%), Crenarchaeota (1-15%),
Gemmatimonadetes (5-10%), Acidobacteria (5-10%), Actinobacteria
(3-10%) and Chloroflexi (3-8%). The majority of identified fungal
OTUs was Ascomycota (40-85%), Basidiomycota (10-60%) and
about 1-12% of the remaining OTUs belonged to Mortierellomycota,
Glomeromycota and Chytridiomycota. The obtained results
suggested the dynamic of microbial taxonomical groups in
rhizosphere soils under the influence of changing farming conditions
(especially N fertilizers) and in addition proposed a relationship
18
between the structure of rhizosphere soil microbiota with
productivity and quality of plants.
3.3.2. Abundance of turmeric rhizosphere fungal communities
under varied N fertilizer rates
3.3.2.1. Diversity indices of turmeric rhizosphere fungal communities
The fungal composition of turmeric rhizosphere at four
fertilization regimes (N0, N150, N350 and N500) was determined by
sequence analysis of ITS amplicons from total DNA samples. After
analyzing the sequence using Uparse software, comparing with Unite
database, OTUs of rhizosphere samples were identified (Table 3.17).
Table 3. 2. ITS amplicons metagenome sequencing data and
analyzed diversity indices.
Sample name N0 (n=3) N150 (n=3) N350 (n=3) N500 (n=3)
Averaged species
number
736 588 718 688
Simpson index 0,927 ± 0,21 0,749 ± 0,09 0,823 ± 0,11 0,833 ± 0,16
ACE index 770 ± 113 623 ± 91 755 ± 106 783 ± 75
Chao1 index 761 ± 83 645 ± 136 754 ± 98 788 ± 177
Shannon-Weaver 5,76 ± 0,3 4,05 ± 0,70 4,43 ± 0,52 4,85 ± 0,48
The principle component analysis (PCA) for OTUs of
rhizosphere soil samples showed a divergence of group H (N150 and
N350) from low yield group L (N0, N500). This result suggested that
the amount of N fertilizer inputs not only affect turmeric yield and
curcuminoids content but also impact the rhizosphere fungal
community structure.
Chemical fertilizers had been determined to be an alteration
factor to microbiological system in different agricultural soils [169]
[170], however this is the first time its impact on rhizosphere fungal
community of turmeric plant C. longa being structurally analyzed
and reported.
19
3.3.2.2. Taxonomic composition of turmeric rhizosphere fungal
communities
The taxonomic composition at phylum and class levels of
turmeric rhizosphere fungal communities in all investigated regimes
appeared relatively uniformed. Accordingly, OTUs of Ascomycota
were prevalent; especially in soil samples of regime N150 with
74.16±9.06% of total identified OTUs. Besides, the proportion of
OTUs belonging to Basidiomycota tended to increase as the raising
amount of N fertilizer. In addition, several fungal genera such as
Zygomycota, Rozellomycota and Blastocladiomycota were found at
higher rates in soil samples of L group (N0 and N500). However,
statistical analysis showed no significant differences in abundance of
Basidiomycota, Zygomycota, Rozellomycota and
Blastocladiomycota between H and L groups (p>0.05).
At class level, OTUs of Sordariomycetes were distributed
more intensively in samples of regimes N350 and N500, while
Eurotiomycetes appeared with a significantly higher proportion in
samples of N0 regime (p<0.05). Agaricomycetes was found as the
most dominant fungal class of Basidiomycota with significant
increased abundance in samples of H group (p<0.05). Findings of
dominant fungal classes in the microbiota of turmeric rhizosphere as
well as their dynamics under varying N fertilizing rates were
unprecedented. These results have contributed to specify a
fundamental reference for extensive studies on optimal fertilization
dosages for turmeric C. longa in Vietnam on worldwide scale.
3.3.3. Differences in composition of selected effective microbial
groups in turmeric rhizosphere
Based on characterized effective microorganisms in turmeric
rhizosphere samples (Section 3.2), an oriented analysis in the
rhizosphere microbial communities of turmeric was performed,
20
focusing on the difference in abundances of PGPR belonging to
Bacilliaceae and AMF belonging to Glomeromycota in four N
fertilization regimes.
3.3.3.1. Bacteria of Bacilliaceae
Depending on the distribution of OTUs belonging to
Bacilliaceae of turmeric rhizosphere samples, three main
taxonomical groups were determined: genus Bacillus, genus
Geobacillus and unclassified bacteria.
Notably, the average proportion of OTUs belonging to
Bacillus in the samples of N0 and N500 regimes (regimes of L
group) accounted for 64 and 65% of the total OTUs of the
Bacilliaceae family, respectively, and reached the peak at over 90%
in samples under N150 and N350 regimes (H group). By statistical
analysis, the difference in abundance of Bacillus-OTUs between two
groups was determined to be significant, with p<0.05. These results
suggest the role of some Bacillus bacteria in turmeric yield and
quality. In particular, the finding may contribute to the orientation for
preparation of biofertilizers from the PGPR strain belonging to
Bacillus for turmeric farming in Vietnam.
3.3.3.2. Fungi of Glomeromycota
Statistical analysis results in taxonomic composition of the
turmeric rhizosphere of groups L and H showed no difference in
proportion of fungi belonging to Glomeromycota at phylum level.
However, the difference between two groups was significant when
considering at the genus level (p<0.05). In detail, the OTUs
belonging to genus Glomus in total OTUs of Glomeromycota
accounted for 13 and 10% in N0 and N500 regimes of L group,
respectively, and for 59 and 36% in N150 and N350 of H group,
respectively.
21
In general, metagenome analysis at the genus level of
Bacilliaceae and Glomeromycota revealed statistically significant
differences between H and L groups, especially at the abundance of
OTUs belonging to genera Bacillus and Glomus, of these effective
representatives were isolated in the turmeric rhizosphere samples.
These results have contributed confirming the prediction of effective
microorganism groups correlating to turmeric yield and quality,
thereby played a pivotal role for selection of indigenous microbial
candidates for preparation of biofertilizer for turmeric plant C. longa.
3.4. Case study for effect of microbial inocula in turmeric
As a combination of isolating result (section 3.2) and genetic
analysis (section 3.3.3), a biofertilizer from strains of PGPR and
AMF was prepared and tested in turmeric plants. The microbial
inocula were composed of Bacillus sp. PGP-V21 and 3 AMF strains
(Glomus sp. AM-N1, Glomus intraradices AM-N2 and Glomus
mosseae AM-N3). These indigenous microbial strains were
determined to be safe in animal models.
Table 3. 3. Growth and productivity parameters of turmeric p
Các file đính kèm theo tài liệu này:
- study_on_rhizosphere_microbial_communities_of_medicinal_plan.pdf