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81.
High concentrations of manganese (Mn), iron (Fe), and aluminium (Al) induced in waterlogged acid soils are a potential constraint for growing sensitive wheat cultivars in waterlogged‐prone areas of Western Australian wheat‐belt. Tackling induced ion toxicities by a genetic approach requires a good understanding of the existing variability in ion toxicity tolerance of the current wheat germplasm. A bioassay for tolerance to high concentration of Mn in wheat was developed using Norquay (Mn‐tolerant), Columbus (Mn‐intolerant), and Cascades (moderately tolerant) as control genotypes and a range of MnCl2 concentrations (2, 250, 500, 750, 1000, 2000, and 3000 μM Mn) at pH 4.8 in a nutrient solution. Increasing solution Mn concentration decreased shoot and root dry weight and intensified the development of toxicity symptoms more in the Mn‐intolerant cv. Columbus than in Norquay and Cascades. The genotypic discrimination based on relative shoot (54% to 79%) and root dry weight (17% to 76%), the development of toxicity symptoms (scores 2 to 4) and the shoot Mn concentration (1428 to 2960 mg kg–1) was most pronounced at 750 μM Mn. Using this concentration to screen 60 Australian and 6 wheat genotypes from other sources, a wide variation in relative root dry weight (11% to 95%), relative shoot dry weight (31% to 91%), toxicity symptoms (1.5 to 4.5), and shoot Mn concentration (901 to 2695 mg kg–1) were observed. Evidence suggests that Mn tolerance has been introduced into Australian wheat through CIMMYT germplasm having “LERMO‐ROJO” within their parentage, preserved either through a co‐tolerance to Mn deficiency or a process of passive selection for Mn tolerance. Cultivars Westonia and Krichauff expressed a high level of tolerance to both Mn toxicity and deficiency, whereas Trident and Janz (reputed to be tolerant to Mn deficiency) were intolerant to Mn toxicity, suggesting that tolerance to excess and shortage of Mn are different, but not mutually exclusive traits. The co‐tolerance for Mn and Al in ET8 (an Al‐tolerant near‐isogenic line) and the absence of Mn tolerance in BH1146 (an Al‐tolerant genotype from Brazil) limits the effectiveness of these indicator genotypes to environments where only one constraint is induced. Wide variation of Mn tolerance in Australian wheat cultivars will enable breeding genotypes for the genetic solution to the Mn toxicity problem. 相似文献
82.
Waterlogging results in high shoot concentrations of iron (Fe), aluminum (Al), and manganese (Mn) in wheat grown in acidic soil. The verification of this observation in several acidic soils, development of screening techniques, and identification of genotypes differing in tolerance made it possible to test whether tolerance of ion toxicities improves performance of wheat in waterlogged acid soils. Six wheat varieties selected for tolerance/intolerance of Al, Mn, and Fe were grown in three acidic soils (pHCaCl2 4.1–4.3) with or without waterlogging for 40 d. In terms of relative shoot dry weight, Al‐, Mn‐, and Fe‐tolerant genotypes tolerated waterlogging better, outperforming intolerant genotypes by 35%, 53%, and 32%, respectively, across the soils. The Al‐tolerant genotype had up to 1.8‐fold better root growth than the intolerant genotype under waterlogging. Waterlogging increased DTPA‐extractable soil Mn (71%) and Fe (89%), and increased shoot Fe (up to 7.6‐fold) and Al (up to 5.9‐fold) for different genotypes and soils. The Al‐tolerant genotype maintained lower tissue concentrations of Al as compared to intolerant genotypes during waterlogging. Waterlogging delayed crop development but distinctly less so in the tolerant than in the intolerant genotypes, thus jeopardizing the capacity of intolerant genotypes to produce yield in Mediterranean climates with dry finish of the season. Pyramiding multiple ion tolerances into current wheat varieties with desirable agronomic and quality characteristics to enhance their performance under waterlogged acid soils should be considered. 相似文献
83.
Morteza Longbaf Dezfouli Amin Ghaedtaheri Saeed Keyvanshokooh Amir Parviz Salati Seyed Mohammad Mousavi Hossein Pasha‐Zanoosi 《Aquaculture Nutrition》2019,25(6):1422-1430
This study was conducted to investigate effects of and interactions between nanoselenium (NanoSe) and nanomagnesium (NanoMg) on growth, humoral immunity, serum biochemistry and antioxidant capacity of juvenile Asian seabass Lates calcarifer reared in freshwater. Four groups of fish with an average weight of 32.78 ± 2.23 g were fed one of the experimental diets for 6 weeks: (a) control (basal diet); (b) NanoSe (basal diet + 4 mg NanoSe/kg diet); (c) NanoMg (basal diet + 500 mg NanoMg/kg diet); and (d) combination (basal diet + 4 mg NanoSe/kg diet + 500 mg NanoMg/kg diet). Fish fed with NanoSe‐supplemented diets (NanoSe and combination) showed higher weight gain, specific growth rate and feed intake. The combination of NanoSe and NanoMg enhanced the immune response. Also, fish fed on combination diet showed higher serum alanine aminotransferase and aspartate transaminase levels but lower glucose concentration. The activities of liver superoxide dismutase, glutathione peroxidase and catalase were not different among all groups, but liver malondialdehyde level was lower in fish fed diets supplemented with NanoSe and/or NanoMg. It could be concluded that NanoSe improved growth performance; the combination of both NanoSe and NanoMg enhanced humoral immunity; and NanoSe and/or NanoMg improved antioxidant capacity in Asian seabass. 相似文献
84.
85.
Rohollah Ghasemi Mehran Torki Hossein Ali Ghasemi 《Tropical animal health and production》2014,46(5):717-723
The objective of this study was to determine the effects of different levels of crude protein (CP) and dietary electrolyte balance (DEB) on productive performance, egg quality, and blood biochemical parameters of laying hens reared during hot summer months. The average minimum and maximum room temperatures recorded from 32 to 42 weeks of age were 27.2 and 36.5 °C, respectively, with relative humidity ranging from 48 to 56 %. A total of 144 Lohmann LSL-Lite laying hens were assigned to each of four dietary treatments with six replicate cages of six birds. The treatments were as follows: CP 15.4 % + DEB 165 mEq/kg (group 1), CP 15.4 % + DEB 250 mEq/kg (group 2), CP 13.9 % + DEB 165 mEq/kg (group 3), and CP 13.9 % + DEB 250 mEq/kg (group 4). In groups 3 and 4, feed conversion ratio and blood uric acid were decreased (P?<?0.05); but the plasma triglyceride level was increased (P?<?0.05) compared to groups 1 and 2. Low-CP diet with DEB 250 (group 4) also induced significant increases of average egg production and eggshell thickness compared to group 1. Blood pH, Na+, and HCO3 ? values were also higher (P?<?0.05) in groups 2 and 4 than in the other groups. These results indicate that, under tropical conditions, using a DEB of 250 mEq/kg achieves a correction of the lay-induced metabolic acidosis and induces a positive effect on eggshell quality when the hens were fed low-protein diet. 相似文献
86.
87.
Partial rootzone drying (PRD) is a water-saving irrigation practice which involves watering only part of the rhizosphere at
each irrigation with the complement left to dry to a pre-determined level. The effect of PRD, applied at different phenological
stages, on yield, fruit growth, and quality of the processing tomato cv. ‘Petopride’ was studied in this experiment. The treatments
were: daily full irrigation (FI) on both sides of the root system considered as the control, and PRD treatments applied at
three phenological stages. These were: during the vegetative stage until the first truss was observed (PRDVS–FT), from the first truss to fruit set (PRDFT–FS), and from fruit set to harvest (PRDFS–H). In some occasions, leaf xylem water potential was lower in each PRD period than in FI. Number of fruits, total fresh and
dry weight of fruit per plant, harvest index, and fruit growth were lower in PRDFT–FS and PRDFS–H plants than in FI and PRDVS–FT plants. However, irrigation water use efficiency, on a dry weight basis, was the same among the treatments. For PRDFT–FS and PRDFS–H treatments, mean fresh weight of fruit and fruit water content were reduced and dry matter concentration of cortex and total
soluble solids concentration of fruit increased compared with FI and PRDVS–FT treatments. Incidence of blossom-end rot was the same among PRDVS–FT, PRDFS–FH, and FI fruit, but it was higher in PRDFT–FS fruit. Fruit skin colour was the same among treatments. Total dry weight of fruit per plant decreased by 23% for PRDFT–FS and by 20% for PRDFS–H relative to FI. Fruit quality improvement in PRDFS–H could compensate for the reduction in total dry weight of fruit where water is expensive for tomato production. But an economical
analysis would be needed to substantiate this. PRD from the first truss to fruit set is not recommended because of the high
incidence of blossom-end rot.
An erratum to this article can be found at 相似文献
88.
89.
Mohammad Hossein Boskabady Mahbobaeh Ghasemzadeh RahbardarZahra Jafari 《Fitoterapia》2011,82(2):162-167
The effect of three concentrations of safranal on histamine (H1) receptors was tested on two groups of tracheal chains incubated with: 1) indomethacin, and 2) indomethacin, propranolol and atropine (n = 6). The EC50 (effective concentration of histamine causing 50% of maximum response) obtained in the presence of chlorpheniramine and all concentrations of safranal in both groups were significantly greater than those of saline (p < 0.05 to p < 0.001). The EC50 obtained in the presence of all concentrations of safranal and maximum response of its two higher concentrations (1.25 and 2.5 μg/mL) in group 2 were greater than in group 1 (p < 0.05 to p < 0.001). 相似文献
90.
Hossein Madadi Emad Mohajeri Parizi Hossein Allahyari Annie Enkegaard 《Journal of pest science》2011,84(4):447-455
Lady beetles are among the most successful predators of aphids in different environments. The functional responses of different
life stages of Hippodamia variegata (Goeze) towards cotton aphids were examined in two different set-ups, a two-dimensional Petri dish set-up with detached leaves
and a three-dimensional set-up with whole plants. In addition, the functional responses in two-dimensional set-ups towards
cotton aphids and the pea aphids were compared. H. variegata exhibited a functional type II response to both cotton aphids and pea aphids irrespective of life stage and spatial scale
of the set-up. Females and fourth instars generally had higher search rates than third instars whereas handling times were
consistently lower for the fourth instar stage compared with the preceding juvenile stage and with females. The spatial dimensions
did not have any significant influence on the functional responses towards cotton aphids, except for third instars which in
the three-dimensional set-up reduced their search rate and increased their handling time. Fourth instars reacted in the same
way to both Aphis gossypii and Acyrthosiphon pisum whereas the functional response parameters for third instars and females were significantly different on the two prey species.
Our study, a part of this first-step evaluation of H. variegata as a biocontrol agent against A. gossypii and A. pisum under field condition, suggest that the voracity of all tested stages of H. variegata towards both aphid species hold good promises for a use of especially fourth instars and females in inundative biocontrol. 相似文献