Agronomic Evaluation of Rapeseed Varieties (Brassica napus L.) in Response to Late-Season Water Deficit Stress

Drought is a wide spread limiting problem seriously influencing rapeseed (Brassica napus L.) growth, production and quality, mostly in dryland regions. However, identification and development of resistant varieties is prohibited by destitute of effective selection criteria. The aim of this study was to evaluate the prevention possibility of rapeseed varieties against terminal-season water deficit stress through selecting suitable varieties. Thirty-four rapeseed varieties were tested in a split plot design based on randomized complete block design (RCBD) with four replications for two years (2005- 2006 and 2006-2007) at Seed and Plant Improvement Institute of Karaj, Iran. Two irrigation levels consisting of irrigation after 80 mm evaporation from class “A” pan during full growing season as normal irrigation (I) and water deficit stress (S) by restricting watering from the flowering phase until full maturity were established in main plots, and subplots were devoted to split application of varieties. Water deficit stress caused noticeable decrease in plant height, silique plant-1, seed silique-1, 1000-kernel weight, seed yield, oil percentage, oil yield and harvest index. There were significant positive correlations between seed yield and yield-related components. Meanwhile, the highest correlation was recorded for number of seeds per siliqua (r= 0.64; P<0.01), suggesting that late-season water deficit stress could be used in selecting drough tolerant varieties. Among varieties, ‘Sunday’ produced the highest seed yield (4938 kg ha-1) and oil yield (2317 kg ha -1) in normal irrigation, and ‘ORW20-3002’ had the highest seed yield (2348 kg ha-1) and oil yield (1000 kg ha -1) in water deficit stress conditions. Accordingly, ‘ORW20-3002’ and ‘Sunday’ can be reported as varieties with sustainable productivity in stress and nonstress conditions

Agronomic Evaluation of Rapeseed Varieties (Brassica napus L.) in Response to Late-Season Water Deficit Stress

Drought is a wide spread limiting problem seriously influencing rapeseed (Brassica napus L.) growth, production and quality, mostly in dryland regions. However, identification and development of resistant varieties is prohibited by destitute of effective selection criteria. The aim of this study was to evaluate the prevention possibility of rapeseed varieties against terminal-season water deficit stress through selecting suitable varieties. Thirty-four rapeseed varieties were tested in a split plot design based on randomized complete block design (RCBD) with four replications for two years (2005- 2006 and 2006-2007) at Seed and Plant Improvement Institute of Karaj, Iran. Two irrigation levels consisting of irrigation after 80 mm evaporation from class “A” pan during full growing season as normal irrigation (I) and water deficit stress (S) by restricting watering from the flowering phase until full maturity were established in main plots, and subplots were devoted to split application of varieties. Water deficit stress caused noticeable decrease in plant height, silique plant-1, seed silique-1, 1000-kernel weight, seed yield, oil percentage, oil yield and harvest index. There were significant positive correlations between seed yield and yield-related components. Meanwhile, the highest correlation was recorded for number of seeds per siliqua (r= 0.64; P<0.01), suggesting that late-season water deficit stress could be used in selecting drough tolerant varieties. Among varieties, ‘Sunday’ produced the highest seed yield (4938 kg ha-1) and oil yield (2317 kg ha -1) in normal irrigation, and ‘ORW20-3002’ had the highest seed yield (2348 kg ha-1) and oil yield (1000 kg ha -1) in water deficit stress conditions. Accordingly, ‘ORW20-3002’ and ‘Sunday’ can be reported as varieties with sustainable productivity in stress and nonstress conditions

Fenugreek (Trigonella foenum-graecum L.): An Important Medicinal and Aromatic Crop

Fenugreek (Trigonella foenum-graecum L.) is an annual forage legume and a traditional spice and aromatic crop that has been grown for centuries across the Indian subcontinent. In addition to South Asia, the crop is also grown in some parts of North Africa, Middle East, Mediterranean Europe, China, South East (SE) Asia, Australia, the USA, Argentina and Canada. The plant has been used traditionally in Indian Ayurvedic medicines as well as in traditional Tibetan and Chinese medication for several centuries. Modern research has also demonstrated that fenugreek seed and leaves are useful in the treatment of a number of diseases including successfully reducing blood sugar and blood cholesterol levels in both animals and humans. The plant has recently attracted great interest in the pharmaceutical, nutraceutical and functional food industries due to its rich medicinal properties

Ecophysiological parameters of medicinal plant Filipendula vulgaris in diverse habitat conditions

SIMPLE SUMMARY: Dropwort (Filipendula vulgaris Moench) is a perennial plant (hemicryptophyte), growing on xerothermic grasslands Festuco-Brometea and changing-wet Molinia meadows in the Eurasian area. Due to the production of active substances, the species is used in folk medicine and phytotherapy. This study includes determining which of the two different habitats occupied by F. vulgaris creates better conditions for its growth and development. Selected physiological parameters of dropwort plants (PSII activity, chlorophyll content, electrolyte leakage, hydrogen peroxide content, and biomass), the occurrence of mycorrhiza, and soil characteristics were investigated. Soil analysis showed a higher content of nutrients in grasslands, and a higher content of heavy metals in meadows. Plants of F. vulgaris growing in the wet meadows achieved a significantly lower mass compared to plants growing in grasslands. The colonization degree of F. vulgaris by arbuscular mycorrhizal fungi (AMF) from both stands oscillated around high values; dropwort formed the Arum type of mycorrhiza. A much higher content of chlorophylls was observed in plants from grasslands. F. vulgaris showed different photosynthetic activity depending on the habitat. Based on chlorophyll fluorescence imaging, higher activity was found in plants from grasslands, compared to plants from meadows, but in specimens from grasslands, there are symptoms of damage to the PSII system. The analyses carried out showed that better conditions for growth and physiological activity of this species are probably associated with grasslands on a calcareous substrate, although the irradiance stress of excess light is visible, manifested, e.g., by little dysfunction of photosynthetic structures. ABSTRACT: This study attempts to determine which of the habitats occupied by Filipendula vulgaris creates better conditions for its growth and development. Selected physiological parameters—PSII activity, chlorophyll content, electrolyte leakage, hydrogen peroxide content as well as biomass, the occurrence of mycorrhiza, and soil characteristics—were investigated. Grassland soils had a higher content of macronutrients and a lower concentration of heavy metals. The degree of colonization of F. vulgaris by AMF (Arum type) oscillated around high values in both types of stands. Plants growing on xerothermic grasslands achieved much better fluorescence parameters than those collected from meadows. Similar results were obtained from the analysis of chlorophyll content. The destabilization degree of cell membranes was significantly higher in plants collected in meadows than in grasslands. Biomass analysis showed higher values of these parameters in grassland plants. In the case of the parameters of fluorescence emission, plants growing on grasslands achieved significantly lower values than plants collected from meadows. The analyses carried out showed that better conditions for growth and physiological activity of F. vulgaris are probably associated with grasslands on a calcareous substrate

Impact of Salicylic Acid and PGPR on the Drought Tolerance and Phytoremediation Potential of Helianthus annus

The present study was aimed to isolate and characterize plant growth promoting rhizobacteria (PGPR) from the rhizosphere of rainfed area (Karak) in Pakistan. The influence of isolated rhizobacteria, in association with salicylic acid (SA), physiological attributes, drought tolerance potential, and phytoremediation in drought-stressed sunflower exposed was investigated. The isolated bacteria were named P1 and P2 and characterized on the basis of colony morphology and biochemical traits. Both PGPR P1 and P2 were identified on the basis of 16S-rRNA gene sequencing as Planomicrobium chinense strain P1 (Accession No. MF616408) and Bacillus cereus strain P2 (Accession No. MF616406). The fresh cultures (24 h old) of isolates were used to soak the seeds pre-sowing. SA was foliar applied at three-leaf-stage. Likewise, the 30-days-old seedlings (three leaf stage) were exposed to drought stress. Drought stress was imposed to 30-days-old plants (three-leaf stage) by withholding water supply for the next 15 days until the soil water content reached 10%. The PGPR and/or SA treatment resulted in significant accumulation of Cd (84%), Pb (66%), and Ni (65%) in the rhizosphere. PGPR also induced accumulation of Cd and Ni in plant shoot. Combined treatment of PGPR and SA increased the Cu (21%), Co (11%), and Zn (8%) accumulation but decreased (12%) the Fe accumulation as compared to coinoculation of PGPR P1 and P2. Inoculation of plants with PGPR significantly increased shoot length (60%), root length (68%), root fresh (61%), and dry (63%) biomass under water stress. The inoculated plants had increased chlorophyll (67%), carotenoid (70%), leaf protein (64%), sugar (64%), and phenolic (62%) contents while lower leaf proline (62%) content, malondialdehyde (MDA) (64%), and antioxidant enzymes (67%) which suggest their role in drought tolerance. It is concluded that integrative use of PGPR in combination with SA found to be an efficacious strategy to improve the phytoremediation of heavy metals and plant growth under stressed conditions particularly under water-deficient conditions