Nowadays, phytochemicals and antioxidants in plants are raising interest in consumers for their roles in the maintenance of human health. Phenolics and flavonoids are known for their health-promoting properties due to protective effects against cardiovascular disease, cancers and other disease. Ginger (Zingiber officinale) is one of the traditional folk medicinal plants and it is widely used in cooking in Malaysia. In this study, four levels of glasshouse light intensities (310, 460, 630 and 790 μmol m−2s−1) were used in order to consider the effect of light intensity on the production, accumulation and partitioning of total phenolics (TP), total flavonoids (TF) and antioxidant activities in two varieties of Malaysian young ginger (Zingiber officinale). TF biosynthesis was highest in the Halia Bara variety under 310 μmol m−2s−1 and TP was high in this variety under a light intensity of 790 μmol m−2s−1. The highest amount of these components accumulated in the leaves and after that in the rhizomes. Also, antioxidant activities determined by the 1,1-Diphenyl-2-picryl-hydrazyl (DPPH) assay in both of varieties, increased significantly (p ≤ 0.01) with increasing TF concentration, and high antioxidant activity was observed in the leaves of Halia Bara grown under 310 μmol m−2s−1. The ferric reducing (FRAP) activity of the rhizomes was higher than that of the leaves in 310 μmol m−2s−1 of sun light. This study indicates the ability of different light intensities to enhance the medicinal components and antioxidant activities of the leaves and young rhizomes of Zingiber officinale varieties. Additionally, this study also validated their medicinal potential based on TF and TP contents.

Physic nut, Jatropha curcas L. is an important bio-fuel crop. The present study was conducted to determine the extent of genetic variation and relationship among 48 J. curcas accessions of from Malaysia using 14 morphological traits during 2009-2010. In respect of all traits, there were highly significant differences among the accessions. The phenotypic coefficient of variation was the highest for oil yield per ha followed by total no. of seed per plant and seed yield. Similarly, the genotypic coefficient of variation was the highest for seed yield followed by oil yield per ha and total number of seeds per plant. Broad sense heritability was high in general and exceeded 63.5% for all the traits studied. The percentages of genetic advance was higher (>70%) for total number of seeds per plant and seed yield. Morphological traits viz. total number of seeds per plant, total number of branches per plant, number of primary branches per plant and seed yields per ha exhibited a high genotypic coefficient of variation, heritability and genetic advance. Seed yield was significantly (p≤ 0.05) and positively correlated with plant height, total branches, leaf greenish, total number of seeds, number of fruits and oil yield. Based on UPGMA cluster and principal component analyses, the accessions, D-01-09 and B-03-02 (grouped into a single cluster) had above average seed yield, oil yield, number of fruits, total number of seeds, leaf greenish, plant height and primary branch compared to other accessions. For the improvement of J. curcas, two accessions (D-01-09 and B-03-02) could be used as parents and required to be hybridized with the accessions (

A field study was conducted to determine the effect of organic and mineral-based fertilizers on phytochemical contents in the tubers of two cassava varieties. Treatments were arranged in a split plot design with three replicates. The main plot was fertilizer source (vermicompost, empty fruit bunch compost and inorganic fertilizer) and sub-plot was cassava variety (Medan and Sri Pontian). The amount of fertilizer applied was based on 180 kg K 2 O ha −1. The tubers were harvested and analyzed for total flavonoids, total phenolics, antioxidant activity and cyanogenic glucoside content. Total phenolic and flavonoid compounds were determined using the Folin-Ciocalteu assay and aluminium chloride colorimetric method, respectively. Different sources of fertilizer, varieties and their interactions were found to have a significant effect on phytochemical content. The phenolic and flavonoid content were significantly higher (p < 0.01) in the vermicompost treatment compared to mineral fertilizer and EFB compost. The total flavonoids and phenolics content of vermicompost treated plants were 39% and 38% higher, respectively, than those chemically fertilized. The antioxidant activity determined using the DPPH and FRAP assays were high with application of organic fertilizer. Cyanogenic glycoside levels were decreased with the application of organic fertilizer. Among the two types of compost, vermicompost resulted in higher nutritional value of cassava tubers. Medan variety with OPEN ACCESSMolecules 2012, 17 2379 application of vermicompost showed the most promising nutritional quality. Since the nutritional quality of cassava can be improved by organic fertilization, organic fertilizer should be used in place of chemical fertilizer for environmentally sustainable production of better quality cassava.

Lettuce varieties Bombilasta BBL and Italian 167 were treated with different concentrations of cadmium (0, 3, 6, 9, and 12 mg/L) in a nutrient film technique (NFT) system to study its toxicity on phytochemicals and nutrient elements. Antioxidants analysis which employed DPPH and FRAP, flavonoids, phenolic, vitamin C, malondialdehyde (MDA), and proline indicated significant effects of Cd treatment on the varieties tested. Different concentration levels of Cd lead to positive interactions in FRAP, phenolic, and MDA but no significant effect in flavonoids, vitamin C, and proline. Contents of macro-and microelements in the varieties were significantly affected with increase in the toxicity levels of Cd in all nutrient elements tested with interactions exhibited for iron, manganese, and zinc.

No abstract

The source and quantity of nutrients available to plants can affect the quality of leafy herbs. A study was conducted to compare quality of Cosmos caudatus in response to rates of organic and mineral-based fertilizers. Organic based fertilizer GOBI (8% N:8% P2O5:8% K2O) and inorganic fertilizer (15% N, 15% P2O5, 15% K2O) were evaluated based on N element rates at 0, 30, 60, 90, 120 kg h−1. Application of organic based fertilizer reduced nitrate, improved vitamin C, antioxidant activity as well as nitrogen and calcium nutrients content. Antioxidant activity and chlorophyll content were significantly higher with increased fertilizer application. Fertilization appeared to enhance vitamin C content, however for the maximum ascorbic acid content, regardless of fertilizer sources, plants did not require high amounts of fertilizer.

Chilli (Capsicum annum L.) plant is a high economic value vegetable in Malaysia, cultivated in soilless culture containers. In soilless culture, the adoption of small container sizes to optimize the volume of the growing substrate could potentially reduce the production cost, but will lead to a reduction of plant growth and yield. By understanding the physiological mechanism of the growth reduction, several potential measures could be adopted to improve yield under restricted root conditions. The mechanism of growth reduction of plants subjected to root restriction remains unclear. This study was conducted to determine the physiological mechanism of growth reduction of root-restricted chilli plants grown in polyvinyl-chloride (PVC) column of two different volumes, 2392 cm3 (root-restricted) and 9570 cm3 (control) in soilless culture. Root restriction affected plant growth, physiological process, and yield of chilli plants. Root restriction reduced the photosynthesis rate and photochemical activity of PSII, and increased relative chlorophyll content. Limited root growth in root restriction caused an accumulation of high levels of sucrose in the stem and suggested a transition of the stem as a major sink organ for photoassimilate. Growth reduction in root restriction was not related to limited carbohydrate production, but due to the low sink demand from the roots. Reduction of the total yield per plant about, 23% in root restriction was concomitant, with a slightly increased harvest index which reflected an increased photoassimilate partitioning to the fruit production and suggested more efficient fruits production in the given small plant size of root restriction.

The seedling stage is a critical period for survival under drought stress. To identify biochemical and molecular drought response changes, oil palm seedlings were exposed to different levels of drought severity. Total chlorophyll, total soluble protein and total proline content were measured while expression of stress responsive genes was quantified using qPCR. The diminishing total chlorophyll (chl) content and the ratio of chl a to chl b (chl a :chl b) were observed to be significant. The significant reduction of chl a was closely related to photosystem II deficiency. Based on the effects of drought on chlorophyll content, the samples can be categorised into mild (7 days of water withholding; DWW), moderate (14 DWW) and severe (21, 28 and 35 DWW). Sample at 21 DWW was used to represent the severe stage. Genes encoding ethylene responsive binding protein, late embryogenesis abundant (LEA), dehydrin (DHN), cold-induced, heat shock protein 70 and metallothionein type 2 were differentially up-regulated in the leaves, while in the roots only LEA and DHN were up-regulated. The proline content increased gradually in both vegetative tissues, while the total soluble protein content was affected by increasing drought severity. The activity of catalase was highest in the roots at the severe drought stage, while guaicol peroxidase activity was shown to be highest in the leaves under mild drought. These findings provide new insights into stress tolerance mechanisms of oil palm seedlings and can be used to develop stress tolerant oil palm through classical breeding and genetic engineering.