Physiological and growth response of rice plants (Oryza sativa L.) to Trichoderma spp. inoculants

Trichoderma spp., a known beneficial fungus is reported to have several mechanisms to enhance plant growth. In this study, the effectiveness of seven isolates of Trichoderma spp. to promote growth and increase physiological performance in rice was evaluated experimentally using completely randomized design under greenhouse condition. This study indicated that all the Trichoderma spp. isolates tested were able to increase several rice physiological processes which include net photosynthetic rate, stomatal conductance, transpiration, internal CO(2) concentration and water use efficiency. These Trichoderma spp. isolates were also able to enhance rice growth components including plant height, leaf number, tiller number, root length and root fresh weight. Among the Trichoderma spp. isolates, Trichoderma sp. SL2 inoculated rice plants exhibited greater net photosynthetic rate (8.66 μmolCO(2) m(−2) s(−1)), internal CO(2) concentration (336.97 ppm), water use efficiency (1.15 μmoCO(2)/mmoH(2)O), plant height (70.47 cm), tiller number (12), root length (22.5 cm) and root fresh weight (15.21 g) compared to the plants treated with other Trichoderma isolates tested. We conclude that beneficial fungi can be used as a potential growth promoting agent in rice cultivation

Effects of elevated atmospheric CO2 on photosynthesis, growth and biomass in Shorea platycarpa F. Heim (Meranti Paya)

Elevated atmospheric CO2 is widely reported to stimulate the plant growth and affect plant physiological processes. However, studies on the respond of tropical plant species to elevated CO2 are quite limited and remain largely unknown. The objective of this study was to investigate the effects of elevated atmospheric CO2 treatments on the photosynthetic characteristics, growth and biomass in Shorea platycarpa. Saplings of S. platycarpa were grown for seven months in the open roof gas chamber supplied with elevated CO2 (800±50 μmol mol-1) and in the shade house with ambient CO2 (400±50 μmol mol-1). Measurements of S. platycarpa growth and photosynthetic characteristics were made at frequent intervals. Biomass characteristics were determined using destructive methods after seven months of treatment and nondestructive method was used for leaf area index (LAI) determination. Photosynthetic rate (A) of S. platycarpa was not significantly affected by elevated CO2. Increased water use efficiency (WUE) of S. platycarpa grown in elevated CO2 was due to the reduced stomatal conductance (gs) and transpiration rate (E). The CO2 elevation had no significant effect on the S. platycarpa relative growth rates (RGR) and biomass but significantly reduced the leaf area. A weak correlation was found between photosynthetic rate (A) and relative growth rate (RGR). The results clearly showed that photosynthesis, growth rate and biomass of S. platycarpa were not significantly enhanced by elevated CO2. The findings indicated that elevated CO2 did not affect a relatively slow growing and a late successional peat swamp tree species

Effects of drought stress on growth and physiological characteristics of roselle (Hibiscus sabdariffa L.)

Drought is the major abiotic stress which causes major losses to agriculture production. This study was conducted to determine the effect of drought stress on the growth and physiological characteristics of Hibiscus sabdariffa. The drought stress treatments were 33, 67 and 100% of the field capacity. Each treatment was replicated five times in a randomized complete block design. According to the results, drought stress had significant effects on the growth and physiological traits of H. sabdariffa. As the drought stress increased, the plant height, leaf area, specific leaf area, fresh and dry weight of shoot and root, photosynthetic rate, stomatal conductance, intercellular CO2 concentration and the transpiration rate decreased. The root-shoot ratio was significantly increased in stressed plants. The changes in number of branches per plant and chlorophyll content were, however, not significant. These findings suggested that H. sabdariffa might be able to tolerate drought stress by increasing the root-shoot ratio and stability of chlorophyll content

Formation and utilisation of acid sulfate soils in Southeast Asia for sustainable rice cultivation

Large parts of lowland areas in Southeast Asia were submerged in seawater some 4300 years ago due to a rise in sea level. During this period, the coastal plains in the region were pyritised. Agricultural development led to oxidisation of the pyrite (FeS2) which in turn allowed weathered mineral silicates to be present in the sediments. High levels of Al and/or Fe are thus present in the soils/water that affect plants and aquatic life. Rice grown on the so-called acid sulfate soils suffer from low pH and Al 3+ and/or Fe2+ toxicity, with yields below the national average. The critical pH and Al concentration for rice growth is 6 and 15-30 uM respectively. The soil become infertile due to high concentrations of acid sulfate. Application of ground magnesium limestone (GML) or basalt in combination with bio-fertiliser fortified with phosphate-solubilising bacteria (PSB) can help reduce the acid sulfate. The PSB not only excrete organic acids that inactivate Al and Fe via chelation, but also increase soil pH to the level that precipitates Al as inert Al-hydroxides. Additionally, rice roots are able to excrete organic acids under the presence of high concentration of Al and/or Fe, which further reduces the availability of Al and Fe in the water

Temperature Stress on Physiological and Morphological Traits in Rhizophora apiculata

الاحتباس الحراري له تأثيرات كبيرة على النظم البيئية الحيوية، والتي تسببت أيضًا في ارتفاع درجات الحرارة وثاني أكسيد الكربون الذي يتبعه تغيرات في العوامل اللاأحيائية المختلفة، والتي تشكل تهديدات لبيئة غابات المنغروف. تم إجراء هذا البحث لفحص الخصائص الفسيولوجية والمورفولوجية لأشجار القرم Rhizophora apiculata فيما يتعلق بارتفاع درجة حرارة الهواء لأنواع الأشجار المتنوعة التي تستجيب لتغير المناخ. حيث تم زراعة الشتلات لمدة ثلاثة أشهر في غرف نمو منظمة بثلاث درجات حرارة متفاوتة 38 درجة مئوية، 21 درجة مئوية تحت ثاني أكسيد الكربون عند 450 جزء في المليون، والمنطقة المحيط بتركيز ثاني أكسيد الكربون 450 ± 20 جزء في المليون تحت متوسط درجة الحرارة عند 28 درجة مئوية كشرط تحكم. تمت معالجة النباتات كل 48 ساعة بـ 3 لترات من الماء المالح بتركيز 28 جزء من المليون. بعد أسبوعين عند درجة حرارة عالية، أظهرت أشجار المانغروف نتائج إيجابية لجميع المعلمات. أدت التغيرات في درجات الحرارة إلى اختلافات كبيرة، مثلاً سلبية لزيادة درجة الحرارة مما أدى إلى تلف شديد للعديد من العينات بينما كانت إيجابية لانخفاض درجة الحرارة مما أدى إلى نمو بطيء. أظهرت النتائج الفسيولوجية انخفاضًا في معدلات التمثيل الضوئي مقارنةً بالعينات الخاضعة للرقابة. تشير هذه النتائج إلى أن مستويات القدرة على التمثيل الضوئي المنخفضة يمكن أن تكون قد حدثت بسبب انخفاض آلية تفاعل تثبيت ثاني أكسيد الكربون، ومواد أصباغ التمثيل الضوئي، والتباين بين معدل التنفس والتمثيل الضوئي.Global warming has had considerable effects on vital ecosystems, which has also been caused by increased temperatures and CO2 that follow changes in different abiotic factors, which poses threats to mangrove forests environment. This research was conducted to examine the physiological and morphological characteristics of the Rhizophora apiculata mangrove regarding higher air temperature for the variety of tree species that respond to climate change. Seedlings were cultivated for three months in regulated growth chambers with three varying temperatures of 38°C, 21°C under CO2 at 450 ppm, and ambient CO2 concentration i.e., 450 ± 20 ppm under average temperature at 28°C as the control condition. The plants were treated every 48 hours with 3 L of saline water of 28 ppt. After two weeks at high temperature, the mangrove showed positive results for all parameters. The temperature variations resulted in major variations, such as negative for increased temperature resulting in extreme damage to many samples while positive for decreased temperature resulting in slow development. The physiological results show decreased photosynthesis rates compared to controlled samples. These findings indicate that low photosynthetic capability levels could have occurred due to reduced CO2 fixative reaction mechanism, photosynthetic pigment material, and the discrepancy between respiratory and photosynthesis rate

Insight and attitude of illness in relation to the relapse rate among schizophrenic patients in Hospital Universiti Sains and Hospital Kota Bharu

Background: Lack of insight in schizophrenia has p~en increasingly in focus. It is frequently reported that schizophrenic patients have poor insight towards their illness. Several rating scales were developed to measure the -insight in relation to the different important aspects. Objectives: This cross-sectional study was conducted to determine the relationship between the level of insight and attitude of illness to the relapse rataamong schizophrenic patients in Hospital Universiti Sains Malaysia and Hospital. Kota Bharu. Methods: . A total of 409 schizophrenic patients who were in· stable condition involved in this cross-sectional study. Various aspects of insight towards illness need for treatment and attribution of the symptom' were assessed with our new scale: Insight and Attitude Scale of Schizophrenia (lASS). The measurement of insight has been based on this new self-administer~d questionnaire. Results: Insight and Attitude Scale of Schizopprenia (lASS) is presented, and evidence in support of its reliability and validity is provided. The result found there is significant corr.elation between patients' insight and relapse rate. Patients with high insight are more likely to have ·less relapses compared to patients with low insight. Conclusion: The scale is a quick and acceptable measure for insight among our population. Patients_ with high insight ~co:e were significantly less likely to have relapse compared w1th those with low 1nsight scoore suggesting that insight may influence the relapse rate among schizophremc patients in the study population

Growth and phenolic constituents’ production in roselle (Hibiscus sabdariffa var. ukmr-2) as influenced by irrigation treatment

This study was carried out to investigate the influence of irrigation on the growth and phenolic content production of Hibiscus sabdariffa var. UKMR-2. The greenhouse cultivation for UKMR-2 was done under control condition using two different irrigation treatments; Water Treatment 1 (WT1) with 1.72 L/plant/day and Water Treatment 1 (WT2) with 0.86 L/plant/day. Roselle calyces were harvested at selected maturation stage and extracted with water via sonication (50 °C, 30 mins). Analysis of total phenolic, anthocyanin content and antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity (DPPH) assay was performed using water extract of roselle calyces. The growth parameters such as plant height, stem diameter, number of branches and leaves were also recorded. The result showed the mean value for WT1 and WT2 treatment respectively: total phenolic content (TPC) were 2.54±0.34 and 2.47±0.34 mg gallic acid equivalent (GAE)/g DW; total anthocyanin content (TAC) were 8.06±1.10 and 7.64±1.38 mg cyanidin-3-glucoside /g DW; IC50 value were 0.28±0.50 and 0.30±0.61mg/mL. WT1 treated plants growth and percentage yield tended to be more higher compared with WT2 treatments. However, there are no significant differences (p>0.05) recorded on the growth parameter with different irrigation treatment. The results also showed that different irrigation treatment have no significant influence on the TAC, TPC and antioxidant activity (p>0.05). All data showed higher quality on growth and calyx’s productivity (including higher concentrations of phenolic contents and antioxidant activity) in UKMR-2 from WT1. Therefore, WT1 (1.72 L/plant/day) is recommended option for roselle cultivation to produce higher phenolic contents, without negative effect on the growth and quality of roselle calyces