Influences of irrigation frequency on the growth and flowering of chrysanthemum grown under restricted root volume were tested. Chrysanthemum cuttings (Chrysanthemum morifolium "Reagan White") were grown in seedling tray which contained coconut peat in volumes of 73 and 140 cm(3). Plants were irrigated with drip irrigation at irrigation frequencies of 4 (266 mL), 6 (400 mL), and 8 (533 mL) times/day to observe their growth and flowering performances. There was interaction between irrigation frequency and substrate volume on plant height of chrysanthemum. Plants grown in 140 cm(3) substrates and irrigated 6 times/day produced the tallest plant of 109.25 cm. Plants irrigated 6 and 8 times/day had significantly higher level of phosphorus content in their leaves than those plants irrigated 4 times/day. The total leaf area, number of internodes, leaf length, and leaf width of chrysanthemums grown in 140 cm(3) substrate were significantly higher than those grown in 73 cm(3) substrate. The numbers of flowers were affected by both irrigation frequencies and substrate volumes. Chrysanthemums irrigated 8 times/day had an average of 19.56 flowers while those irrigated 4 times/day had an average of 16.63 flowers. Increasing irrigation frequency can improve the growth and flowering of chrysanthemums in small substrate volumes.
Tissue culture studies of Celosia cristata were established from various explants and the effects of various hormones on morphogenesis of this species were examined. It was found that complete plant regeneration occurred at highest percentage on MS medium supplemented with 2.0 mg/L NAA and 1.5 mg/L BAP, with the best response showed by shoot explants. In vitro flowering was observed on MS basal medium after six weeks. The occurrence of somaclonal variation and changes in cellular behavior from in vivo and in vitro grown plants were investigated through cytological studies and image analysis. It was observed that Mitotic Index (MI), mean chromosome numbers, and mean nuclear to cell area ratio of in vitro root meristem cells were slightly higher compared to in vivo values. However, in vitro plants produced lower mean cell areas but higher nuclear areas when compared to in vivo plants. Thus, no occurrence of somaclonal variation was detected, and this was supported by morphological features of the in vitro plants.
The possibility of controlling Fusarium wilt--caused by Fusarium oxysporum sp. cubensec (race 4)--was investigated by genetic engineering of banana plants for constitutive expression of rice thaumatin-like protein (tlp) gene. Transgene was introduced to cauliflower-like bodies' cluster, induced from meristemic parts of male inflorescences, using particle bombardment with plasmid carrying a rice tlp gene driving by the CaMV 35S promoter. Hygromycin B was used as the selection reagent. The presence and integration of rice tlp gene in genomic DNA confirmed by PCR and Southern blot analyses. RT-PCR revealed the expression of transgene in leaf and root tissues in transformants. Bioassay of transgenic banana plants challenged with Fusarium wilt pathogen showed that expression of TLP enhanced resistance to F. oxysporum sp. cubensec (race 4) compared to control plants.
Phenylalanine ammonia lyase (PAL) plays a major role in plant growth, development and adaptation. In Arabidopsis thaliana, the enzyme is encoded by four genes, namely PAL1, PAL2, PAL3, and PAL4 with PAL1 and PAL2 being closely related phylogenetically and functionally. PAL1 promoter activities are associated with plant development and are inducible by various stress agents. However, PAL2 promoter activities have not been functionally analysed. Here, we show that the PAL2 promoter activities are associated with the structural development of a plant and its organs. This function was inducible in an organ-specific manner by the avirulent strain of Pseudomonas syringae pv. tomato (JL1065). The PAL2 promoter was active throughout the course of the plant development particularly in the root, rosette leaf, and inflorescence stem that provide the plant with structural support. In aerial organs, the levels of PAL2 promoter activities were negatively correlated with relative positions of the organs to the rosette leaves. The promoter was inducible in the root following an inoculation by JL1065 in the leaf suggesting PAL2 to be part of an induced defence system. Our results demonstrate how the PAL2 promoter activities are being coordinated and synchronised for the structural development of the plant and its organs based on the developmental programme. Under certain stress conditions the activity may be induced in favour of certain organs.
Ant-garden (AG) associations are systems of epiphytic plants and arboricolous (i.e., tree-living) ants, in which the ants build fragile carton nests containing organic material. They collect and incorporate seeds or fruits of epiphytes that then germinate and grow on the nest [sensu Corbara et al. (1999) 38:73-89]. The plant roots stabilize the nest carton. AGs have been well-known in the neotropics for more than 100 years. In contrast, reports on similar associations in the paleotropics are scarce so far. After discovering a first common AG system on giant bamboo [Kaufmann et al. (2001) 48:125-133], we started a large-scale survey for AGs in Peninsular Malaysia, Borneo, Java, and southern Thailand. A great variety of AG systems (altogether including 18 ant species and 51 plant species) was discovered and is described in the present paper. The high number of species participating in AG associations was reflected by a great variability in the specific appearances of the nest gardens. Frequently, further groups of organisms (e.g., hemipteran trophobionts, fungi) were also involved. Preference patterns of particular ant and epiphyte species for each other and for particular phorophytes (carrier trees) were detected. We integrate domatia-producing, so-called ant-house epiphytes in our study and compare their phases of establishment, as well as other characteristics, to "classical" AGs, coming to the conclusion that they should be regarded only as a special type of AG epiphyte and not as a separate ecological category.
Constructed wetland (CW) is a low-cost alternative technology to treat wastewater. This study was conducted to co-treat landfill leachate and municipal wastewater by using a CW system. Typha domingensis was transplanted to CW, which contains two substrate layers of adsorbents, namely, ZELIAC and zeolite. Response surface methodology and central composite design have been utilized to analyze experimental data. Contact time (h) and leachate-to-wastewater mixing ratio (%; v/v) were considered as independent variables. Colour, COD, ammonia, nickel, and cadmium contents were used as dependent variables. At optimum contact time (50.2 h) and leachate-to-wastewater mixing ratio (20.0%), removal efficiencies of colour, COD, ammonia, nickel, and cadmium contents were 90.3%, 86.7%, 99.2%, 86.0%, and 87.1%, respectively. The accumulation of Ni and Cd in the roots and shoots of T. domingensis was also monitored. Translocation factor (TF) was >1 in several runs; thus, Typha is classified as a hyper-accumulator plant.
The presence of abundant oil palm residues in Malaysia prompted the need to utilize this waste to avoid environmental
pollution. This waste was abundant at the oil palm mill and accounted for almost 50% of production. The study was
conducted to determine the morphological effect of Palm Oil Mill Effluent (POME) sludge on the maize growth performance
and gas exchange. Physicochemical, growth morphology and gas exchange was measured after treated with POME sludge
from different treatment pond systems: Mixing, anaerobic, facultative, algae and dumping. The results indicated the
pH, C, and CEC of mixing the < anaerobic < facultative < algae < dumping ponds. There was a significant presence of
macronutrient (N, Mg, Ca, Fe, S) in the treated POME sludge, contrary to the presence of heavy metal (Cd, Cu, Ni and
Pb) elements which were not significantly different in all the treatments and lower than WHO/FAO standard. Root Shoot
Ratio (RSR) and Specific Leaf Area (SLA) indicated significant difference in biomass accumulation and yield compared to
the control. The gas exchange variable was a significant difference on stomata conductivity (Gs) and transpiration rate
(E). However, the POME sludge from the facultative, algae and dumping ponds showed positive correlations between net
photosynthesis, stomata conductivity and transpiration rate. Indeed, the increased transpiration rate (E) was correlated
with stomata conductance (Gs) after treatment with anaerobic, facultative, algae and dumping ponds. In conclusion, the
POME sludge amendment was able to increase the maize biomass and yield.
With the population growth, urbanization and industrialization, China has become a hotspot of atmospheric deposition nitrogen (ADN), which is a threat to ecosystem and food safety. However, the impacts of increased ADN on rice growth and grain metal content are little studied. Based on previous long-term ADN studies, greenhouse experiment was conducted with four simulated ADN rates of 0, 30, 60 and 90 kg N ha-1 yr-1 (CK, N1, N2 and N3 as δ15N, respectively) to assess rice growth and metal uptake in a red soil ecosystem of southeast China during 2016-2017. Results showed that simulated ADN could promote rice growth and increase yields by 15.68-24.41% (except N2) and accumulations of cadmium (Cd) or copper (Cu) in organs. However, there was no linear relationship between ADN rate and rice growth or Cd or Cu uptake. The 15N-ADN was mainly accumulated in roots (21.31-67.86%) and grains (25.26-49.35%), while Cd and Cu were primarily accumulated in roots (78.86-93.44% and 90.00-96.24%, respectively). 15N-ADN and Cd accumulations in roots were significantly different between the two growing seasons (p
The world faces two enormous challenges that can be met, at least in part and at low cost, by making certain changes in agricultural practices. There is need to produce enough food and fibre for a growing population in the face of adverse climatic trends, and to remove greenhouse gases to avert the worst consequences of global climate change. Improving photosynthetic efficiency of crop plants can help meet both challenges. Fortuitously, when crop plants' roots are colonized by certain root endophytic fungi in the genus Trichoderma, this induces up-regulation of genes and pigments that improve the plants' photosynthesis. Plants under physiological or environmental stress suffer losses in their photosynthetic capability through damage to photosystems and other cellular processes caused by reactive oxygen species (ROS). But certain Trichoderma strains activate biochemical pathways that reduce ROS to less harmful molecules. This and other mechanisms described here make plants more resistant to biotic and abiotic stresses. The net effect of these fungi's residence in plants is to induce greater shoot and root growth, increasing crop yields, which will raise future food production. Furthermore, if photosynthesis rates are increased, more CO2 will be extracted from the atmosphere, and enhanced plant root growth means that more sequestered C will be transferred to roots and stored in the soil. Reductions in global greenhouse gas levels can be accelerated by giving incentives for climate-friendly carbon farming and carbon cap-and-trade programmes that reward practices transferring carbon from the atmosphere into the soil, also enhancing soil fertility and agricultural production.
Basal stem rot, caused by the basidiomycete fungus, Ganoderma boninense, is an economically devastating disease in Malaysia. Our study investigated the changes in lignin content and composition along with activity and expression of the phenylpropanoid pathway enzymes and genes in oil palm root tissues during G. boninense infection. We sampled control (non-inoculated) and infected (inoculated) seedlings at seven time points [1, 2, 3, 4, 8, and 12 weeks post-inoculation (wpi)] in a randomized design. The expression profiles of phenylalanine ammonia lyase (PAL), cinnamyl alcohol dehydrogenase (CAD), and peroxidase (POD) genes were monitored at 1, 2, and 3 wpi using real-time quantitative polymerase chain reaction. Seedlings at 4, 8, and 12 wpi were screened for lignin content, lignin composition, enzyme activities (PAL, CAD, and POD), growth (weight and height), and disease severity (DS). Gene expression analysis demonstrated up-regulation of PAL, CAD, and POD genes in the infected seedlings, relative to the control seedlings at 1, 2, and 3 wpi. At 2 and 3 wpi, CAD showed highest transcript levels compared to PAL and POD. DS increased progressively throughout sampling, with 5, 34, and 69% at 4, 8, and 12 wpi, respectively. Fresh weight and height of the infected seedlings were significantly lower compared to the control seedlings at 8 and 12 wpi. Lignin content of the infected seedlings at 4 wpi was significantly higher than the control seedlings, remained elicited with no change at 8 wpi, and then collapsed with a significant reduction at 12 wpi. The nitrobenzene oxidation products of oil palm root lignin yielded both syringyl and guaiacyl monomers. Accumulation of lignin in the infected seedlings was in parallel to increased syringyl monomers, at 4 and 8 wpi. The activities of PAL and CAD enzymes in the infected seedlings at DS = 5-34% were significantly higher than the control seedlings and thereafter collapsed at DS = 69%.
We previously evaluated the biochemical changes induced by the local product TCM for diabetes (TCM-D™) on blood glucose levels and other biochemical changes in normal mice fed orally with the recommended human dose (30 ml/kg daily) and ten times this dose for eight weeks. TCM-D™ is an aqueous extract of the roots of Trichosanthes kirilowii Maxim, Paeonia lactiflora Pall, Glycyrrhiza uranlensis Fisch. and Panax ginseng Meyer (red) combined at the dry weight proportions of 36%, 28%, 18% and 18% respectively. The study showed that at these dosages the blood glucose levels as well as the body weights in treated mice were significantly reduced when compared with pretreatment values and control animals. The present study evaluated the effect of the extract in a mouse model of Type 1 diabetes mellitus.
The Clitoria ternatea (Fabaceae) root, seed, and leaf are commonly used in Ayurvedic medicine in Malaysia and Indonesia. The methanol leaf extracts of C. ternatea was tested for toxicity by means of brine shrimp lethality test and acute oral toxicity assay. In the brine shrimp lethality test, the leaf extract were non-toxic or showed weak lethality (LC50 > 1 mg/ml) at the 6 h, 12 h and 24 h incubation period. Nevertheless, at the 48 h incubation time, the leaf extract exhibited moderate toxicity activity with LC50 values of 0.49 mg/ml. In the acute toxicity study using mice, the median lethal dose (LD50) of the extract was found greater than 2000 mg/kg, and we found no pathological changes by means of macroscopic examination of tissues of mice treated with the extract. We conclude that the C. ternatea leaf extract is not toxic in mice and brine shrimp.
Successful biotrophic plant pathogens can divert host nutrition towards infection sites. Here we describe how the protist Plasmodiophora brassicae establishes a long-term feeding relationship with its host by stimulating phloem differentiation and phloem-specific expression of sugar transporters within developing galls. Development of galls in infected Arabidopsis thaliana plants is accompanied by stimulation of host BREVIS RADIX (BRX), COTYLEDON VASCULAR PATTERN 2 (CVP2) and OCTOPUS (OPS) gene expression leading to an increase in phloem complexity. We characterised how the arrest of this developmental reprogramming influences both the host and the invading pathogen. Furthermore, we found that infection leads to phloem-specific accumulation of SUGARS WILL EVENTUALLY BE EXPORTED TRANSPORTERS (SWEET11 and SWEET12) facilitating local distribution of sugars towards the pathogen. Utilising Fourier-transform infrared (FTIR) microspectroscopy to monitor spatial distribution of carbohydrates, we found that infection leads to the formation of a strong physiological sink at the site of infection. High resolution metabolic and structural imaging of sucrose distributions revealed that sweet11 sweet12 double mutants are impaired in sugar transport towards the pathogen, delaying disease progression. This work highlights the importance of precise regulation of sugar partitioning for plant-pathogen interactions and the dependence of P. brassicae's performance on its capacity to induce a phloem sink at the feeding site.
This study was conducted to screen the endophytic bacteria as a biological control agent (BCA) against Ganoderma boninense. A total of 581 endophytic bacteria were successfully isolated from symptomless oil palm root tissues at Teluk Intan, Perak, Malaysia. Three endophytic bacteria, Pseudomonas aeruginosa GanoEB1, Burkholderia cepacia GanoEB2, and Pseudomonas syringae GanoEB3 were found to have a potential as BCA based on their percentage inhibition of radial growth (PIRG) in dual culture and culture filtrate tests. Two nursery trials were conducted to evaluate the capability of these bacteria to suppress Ganoderma disease in oil palm seedlings that were artificially infected with G. boninense using rubber wood block (RWB) sitting technique. The percentage of disease incidence (DI), severity of foliar symptoms (SFS) and dead seedlings were used as the assessment tools. As a result, DI and SFS have developed much slower in the seedlings that were pre-treated with bacteria compared to untreated seedlings. After 6 months of inoculation, Ganoderma disease incidence was reduced from 62-75% in the seedlings treated with P. aeruginosa GanoEB1, followed by B. cepacia GanoEB2 (31-59%) and P. syringae GanoEB3 (30-31%). Among these three endophytic bacteria, P. aeruginosa GanoEB1 was the most effective in controlling Ganoderma disease and the dead seedlings were in the range of 13.3-26.7%, followed by B. cepacia GanoEB2 (33.3% for both trials) and P. syringae GanoEB3 (33.3-40.0%) compared to untreated seedlings at 60% for both trials. A field study needs to be conducted to verify their effectiveness in controlling Ganoderma in oil palm.
In the present study, capability of water hyacinth in removing heavy metals such as Cadmium (Cd), Chromium (Cr), Copper (Cu), Zinc (Zn), Iron (Fe), and Boron (B) in ceramic wastewater was investigated. The metal removal efficiency was identified by evaluating the translocation of metals in roots, leaves and shoot of water hyacinth. The heavy metal removal efficiency followed the order Fe>Zn>Cd>Cu>Cr>B during the treatment process. Water hyacinth had luxury consumption of those 6 elements. This study used the circulation system with 3 columns of plants which functioned as bioremediation of the sample. The concentration of metals in roots is much higher 10 times than leaves and stems. Roots give the result of metalR>metalL. The removal concentration from water hyacinth was estimated under pH of 8.21 to 8.49. This study proves water hyacinth to be a best plant for phytoremediation process
Mycorrhizal fungi are an essential component to consider for better management of soil fertility, particularly in
degraded rangelands of drylands. The present article presents a field survey of colonization and intensity of arbuscular
mycorrhizal fungi (AMF) on prickly pear (Opuntia ficus-indica) roots from young (5 years old) and old (more than 20
years) plantations. The results observed were explained by seasonality and edaphic factors. Prickly pear roots showed
a mycorrhizal frequency (F%) up to 100% of colonization and a mycorrhizal intensity (M%) that may exceed 70%.
According to ANOVAs, both F% and M% varied significantly between Prickly pear plantation ages, but only M% between
seasons. The Generalized linear model showed that edaphic factors have no effect on the variation of F%. However
the statistical model showed that M% were significantly influenced by active CaCO3
, organic matter, carbon, nitrogen,
phosphorus contents and C/N. Our findings highlight the importance of mycorrhization in rehabilitation programs of
degraded rangelands by prickly pear plantations in semiarid and arid lands, particularly during early plant ages and
under environmental abiotic stresses such as climate and soil type.
Maize is an imperative grain crop used as a staple food in several countries around the world. Water deficiency is a serious
problem limiting its growing area and production. Identification of drought tolerant maize germplasm is comparatively
easy and sustainable approach to combat this issue. Present research was conducted to evaluate 50 maize genotypes
for drought tolerance at early growth stage. Drought tolerance was assessed on the basis of several morphological
and physiological parameters. Analysis of variance showed significant variation among the tested maize genotypes for
recorded parameters. Principal component analysis revealed important morpho-physiological traits that were playing
key role in drought tolerance. Correlation studies depicted significant positive correlation among the attributes such as
fresh shoot length (FSL), fresh root length (FRL), dry shoot weight (DSW), dry root weight (DRW), relative water contents
(RWC) and total dry matter (TDM) while a strongly negative correlation was observed among RWC and excised leaf
water loss. Results concluded that the parameters fresh shoot weight, fresh root weight, FRL, DRW, TDM, cell membrane
thermo stability (CMT) and RWC can be useful for rapid screening of maize germplasm for drought tolerance at early
growth stages. Furthermore, the genotypes 6, 16, 18, 40, 45 and 50 can be used as a drought tolerant check in breeding
programs. Moreover, biplot analysis along with other indices was proved to be a useful approach for rapid and cost
efficient screening of large number of genotypes against drought stress condition.
Allelopathy is a process in which one plant species may usefully or adversely affect the growth of other plant species
through the production of allelochemicals. During the present investigation, mulch effect of Jatropha curcas leaves was
evaluated on seed germination and seedling growth of maize varieties viz. Pioneer (V1), Azam (V2) and Jalal (V3). Mulch
was applied at 1 and 2 tons/hectare. Phenolic compounds were detected in Jatropha curcas leaf (131.15 mg gallic acid
eq./gm extract). Mulch applied at 2 tons/hectare significantly reduced seed germination (%), germination index, relative
water content, root width and seedling dry weight. From the findings of the present investigation, it was inferred that
Jatropha curcas leaves exhibited phytotoxic effects on maize at high concentrations.
This paper presents the results of mercury analysis on 786 abiotic (surface sediments) and biotic (plant and animal tissues) samples collected from 10 sites at Matang Mangrove Forest Reserve in Peninsular Malaysia. Sediment samples were collected at the surface level from both river bank and forest understory. Whereas plant tissues obtained from Rhizophora apiculata Blume and Rhizophora mucronata L. consisted of leaves (in four stages namely young, mature, senescent and decomposing), bark and roots (divided into xylem, cortex and epidermis), the animal samples were represented by muscle tissue of the gastropod Cassidula aurisfelis Bruguière and the cockle Tegillarca granosa L. The mercury concentration measurements were obtained through a cold vapor atomic absorption spectrometer. The core data have been analysed and interpreted in the paper "Distribution of mercury in sediments, plant and animal tissues in Matang Mangrove Forest Reserve, Malaysia" [1].
A proteomic analysis of a soil-dwelling, plant growth-promoting Azotobacter vinelandii strain showed the presence of a protein encoded by the hypothetical Avin_16040 gene when the bacterial cells were attached to the Oryza sativa root surface. An Avin_16040 deletion mutant demonstrated reduced cellular adherence to the root surface, surface hydrophobicity, and biofilm formation compared to those of the wild type. By atomic force microscopy (AFM) analysis of the cell surface topography, the deletion mutant displayed a cell surface architectural pattern that was different from that of the wild type. Escherichia coli transformed with the wild-type Avin_16040 gene displayed on its cell surface organized motifs which looked like the S-layer monomers of A. vinelandii. The recombinant E. coli also demonstrated enhanced adhesion to the root surface.