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1.
An experiment was conducted to assess the zinc (Zn) availability to wheat in alkaline soils during Rabi 2009–2010. Wheat seedlings in pots having 2 kg alkaline sandy soil per pot were treated with 5, 10 and 15 kg Zn ha?1 as soil and with 0.5 and 1.0% zinc sulfate (ZnSO4) as foliar application. Results showed that Zn increasing levels in soil helped in phosphorus uptake up to boot stage but its conversion to grain portion lacked in Zn treated plants. Potassium (K) uptake also increased up to 6.24% in boot stage with treatment of 10 kg Zn ha?1 + 1.0% ZnSO4 foliar spray. Zinc (Zn) concentration increased in plant tissues with the increasing level of Zn application but this disturbed the phosphorus (P)-Zn interaction and, thus, both of the nutrients were found in lesser quantities in grains compared to the control. Despite of the apparent sufficient Zn level in soil (1.95 mg kg?1), improvement in growth and yield parameters with Zn application indicate that the soil was Zn deplete in terms of plant available Zn. The above findings suggest that the figure Zn sufficiency in alkaline soil (1.0 mg kg?1) should be revised in accordance to the nature and type of soils. Furthermore, foliar application of Zn up to 1.0% progressively increased yield but not significantly; and it was recommended that higher concentrations might be used to confirm foliar application of Zn as a successful strategy for increasing plant zinc levels. 相似文献
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Abdellah Akhkha Donald D. Clarke Peter J. Dominy 《Physiological and Molecular Plant Pathology》2003,62(6):347-354
The relative levels of tolerance of two wild barley lines (Hordeum spontaneum), B19909 and I-17-40, and one cultivated barley (Hordeum vulgare), cv. Prisma, to Blumeria graminis f.sp. hordei were determined by comparing the effects of different levels of infection on the photosynthesis and respiration rates of the third leaf. Infection caused the early onset of senescence in all three lines, and in particular in cv. Prisma, and was accompanied by decreases in gross and net photosynthesis rates, increases in respiration rates, and loss of chlorophyll. The onset of senescence occurred at approximately the same time in infected leaves of the two wild lines, but once triggered, photosynthesis rates and chlorophyll levels declined more rapidly in I-17-40 than in B19909. A burst of respiratory activity accompanied the onset of senescence, and this was greatest in cv. Prisma. Conidial production was higher in B19909, indicating a higher level of tolerance in this line. 相似文献
3.
镉胁迫对水稻生长和营养代谢的影响 总被引：47，自引：3，他引：47
选择苗期镉耐性和籽粒镉含量差异明显的4个晚粳稻品种为供试材料，研究了有毒重金属镉胁迫对水稻生长和营养代谢的影响。结果表明，镉胁迫显著降低各品种的产量和每株穗数、每穗总粒数、结实率、粒重等经济性状以及不同生育期的地上部干物质重，但苗期镉耐性较强的品种受抑制程度要小于镉耐性较弱的品种，相近耐性类型中籽粒镉含量较高的品种比镉含量较低的品种受害严重。因此可用苗期镉的耐性评价不同基因型耐镉性的差异。镉胁迫显著增加各品种地上部茎叶和籽粒的镉含量和积累量，但增加的程度品种间存在着很大差异。植株镉含量随生育进程而逐步下降，而植株镉积累量随生育进程而增加，与干物质产量一致。本研究还表明，镉胁迫显著影响籽粒中一些矿质元素的含量，按镉对籽粒元素含量的效应可将所涉及的8种元素划分为二类，一类呈现为抑制效应，包括K、P、Mg、Mn和Zn等5种；另一类呈现为促进效应，包括Fe、Cu和Ca等3种。此外，镉胁迫对游离氨基酸含量的影响与氨基酸种类和品种有关。值得注意的是，谷氨酸和半胱氨酸等含硫氨基酸的合成受镉胁迫的抑制，且耐性较弱的品种受抑制程度明显大于镉耐性较强的品种。同时，耐性较强的品种这些氨基酸的含量均高于耐性较弱的品种，说明这些氨基酸的代谢可能与水稻品种的Cd耐性反应有关。 相似文献
4.
The effects of increasing periods under sugarcane monoculture (managed with preharvest burning) on soil organic matter content and related soil properties were investigated in the 0- to 10-cm layer of a sandy coastal Ochric Cambisol (Glenrosa soil) and a red Rhodic Ferralsol (Hutton soil) from the sugar belt of the South African province of KwaZulu-Natal. The organic C content at both sites under undisturbed vegetation was between 40 and 50 g C kg-1. This declined exponentially with increasing years under sugarcane. For the Glenrosa site it reached a new equilibrium level after about 30-40 years. After 20-30 years of sugarcane, organic C content had declined to about 33 g kg-1 for the Hutton soil and 17 g kg-1 for the Glenrosa soil. The higher organic matter content maintained at the Hutton site was attributed mainly to clay protection of organic matter since the clay content of the Hutton soil was 62% compared to 18% for the Glenrosa soil. For the same reason, aggregate stability was also generally higher in the Hutton than Glenrosa soil. The loss of soil organic matter under sugarcane resulted in a concomitant decline in soil microbial biomass C, percentage of organic C present as microbial biomass, basal respiration, fluorescein diacetate hydrolytic activity and aggregate stability. At the Glenrosa site, the natural '13C abundance in soils was used to calculate the loss of forest-derived, native soil C and the concomitant input of sugarcane-derived C. Sugarcane-derived organic C increased over time until it accounted for about 61% of organic C in the surface 10 cm in soils that had been under sugarcane for greater than 50 years. It was concluded that sugarcane production can cause a large decline in soil organic matter content and that practices such as green cane harvesting, zero tillage and use of green crops should be promoted to help ameliorate the problem. 相似文献
5.
Abstract The nutritional profile of sweet sorghum [Sorghum bicolor (L.) Moench] cultivars grown under acid soil field stress conditions is a critical consideration when developing plants which are adapted to these infertile soils. Uptake and accumulation of macro‐ and micronutrients vary among genotypes and ultimately Influence plant growth and development. This study compared fourteen sweet sorghum germplasm lines and varieties for their Individual patterns of leaf nutrient concentrations and productivity when grown under acid soil field conditions (pH 4.45 to pH 4.85) at three locations over a two‐year period. Significant year x location interactions were found for Fe, K, and Ca concentrations at both Blairsville and Calhoun and for Mn and P levels at Blairsville and Calhoun, respectively. Data from Calhoun on plant height, dry weight, visual stress ratings, and rainfall indicate a possible association between drought tolerance and acid soil tolerance in sorghum. No significant differences in A1 concentrations were found among these sweet sorghum lines and varieties, which indicate that their acid soil tolerance mechanisms are probably not related to A1. MN 1054 accumulated the highest levels of Mn in the three acid soils. The highest concentrations of Mg and P were found in Brandes. MN 960 had the highest visual stress ratings (highest susceptibility) while Brandes, Ramada, Roma, and Wray were the most tolerant. All fourteen cultivars apparently have some tolerance to acid soil stress conditions. 相似文献
6.
M.A. Bower M. Whitten R.E.R. Nisbet M. Spencer K.M. Dominy A.M. Murphy R. Cassidy E. Barrett E.W. Hill M. Binns 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2013,130(3):227-235
The potential future earnings and therefore value of Thoroughbred foals untested in the racing arena are calculated based on the performance of their forebears. Thus, lineage is of key importance. However, previous research indicates that maternally inherited mitochondrial DNA (mtDNA) does not correspond to maternal lineage according to recorded pedigree, casting doubt on the voracity of historic pedigrees. We analysed mtDNA of 296 Thoroughbred horses from 33 maternal lineages and identified an interesting trend. Subsequent to the founding of the Thoroughbred breed in the 16th century, well‐populated maternal lineages were divided into sub‐lineages. Only six in 10 of the Thoroughbreds sampled shared mitochondrial haplotype with other members of their maternal lineage, despite having a common maternal ancestor according to pedigree records. However, nine in 10 Thoroughbreds from the 103 sub‐lineages sampled shared mtDNA with horses of their maternal pedigree sub‐lineage. Thus, Thoroughbred maternal sub‐lineage pedigree represents a more accurate breeding record than previously thought. Errors in pedigrees must have occurred largely, though, not exclusively, at sub‐lineage foundation events, probably due to incomplete understanding of modes of inheritance in the past, where maternal sub‐lineages were founded from individuals, related, but not by female descent. 相似文献
7.
Zhi Yong Ju Dong‐Fang Deng Warren G. Dominy Ian P. Forster 《Journal of the World Aquaculture Society》2011,42(5):633-644
This study investigated the effectiveness of dietary supplementation of astaxanthin (Ax) from the Haematococcus pluvialis on growth, survival, and pigmentation in Pacific white shrimp. Ten test diets were processed to contain five levels of Ax (25, 50, 75, 100, and 150 mg/kg as fed basis) by adding the natural or synthetic Ax to a basal diet containing no Ax. Each diet and a commercial shrimp feed were fed to four replicate tanks of shrimp (12 shrimp/tank) for 8 wk. Neither the natural nor synthetic Ax affected shrimp growth or survival. After cooking, shrimp fed the diets containing the natural Ax exhibited a strong red color, compared to the light pink color of shrimp fed the remaining diets. Colorimetric readings and Ax content in cooked shrimp demonstrated that the natural esterified Ax had greater pigmentation efficiency than synthetic free Ax (P < 0.05). The Ax contents in shrimp tail muscle demonstrated significant correlation with the levels of dietary Ax. The supplementation level of the natural Ax for optimum pigmentation efficiency is in a range of 75–100 mg/kg diet. The Ax product used in this study contained only a small amount (ca. 5.0%) of other carotenoids, indicating that the high pigmentation efficiency was mainly due to algal esterified Ax. 相似文献
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Abstract.— To examine the need for supplemental dietary methionine and to determine the ability of different methionine sources to meet this need for Pacific white shrimp, Litopenaeus vannamei, a growth trial was conducted. A control diet (30% crude protein) was formulated to be deficient in methionine by inclusion of high levels of dehulled, solvent‐extracted soybean meal and with no fish meal (methionine level was 0.45% of diet as fed, 1.5% of total amino acids). Three test diets were manufactured based on the control diet but supplemented with l ‐methionine, dl ‐methionine, or an analog of methionine (2‐hydroxy‐4‐methylthio butanoic acid [HMTBA], calcium salt) at the level of 0.5% as fed (equivalent to 1.5% of total amino acids). Cystine was constant among these diets at 0.5% of diet as fed. A commercial feed (30% crude protein) was included as a reference. The culture vessels were flat‐bottomed, cylindrical, black fiberglass tanks (1.5‐m diameter) initially filled with 1000 L seawater and supplied with aeration and seawater from a well at a rate of 2 L/min. At the end of the trial, all surviving shrimp were counted and weighed. The trial was run outdoors, with a mean water temperature of 25.9 C. The mean survival, final weight, growth rate, and feed efficiency of shrimp in the control group were 95.9%, 10.8 g, 0.93 g/wk, and 0.44 g/g, respectively. The mean values of all the test treatments were 96.9%, 11.6 g, 1.00 g/wk, and 0.47 g/g, respectively. The final weight and growth rate of shrimp fed the control diet were significantly lower than those of shrimp fed the methionine‐supplemented diets, indicating that this species has a requirement for dietary methionine. There were no significant differences (P > 0.05) in any of the parameters among the test treatments, indicating that l ‐methionine, dl ‐methionine, and HMTBA can be used to meet the methionine requirement of this species under these experimental conditions. It is concluded that the three sources of methionine examined in this trial, l ‐methionine, dl ‐methionine, and HMTBA, are similar in their ability to meet the methionine requirement of this species. 相似文献
10.
Zhi Yong Ju Ian P Forster Dong‐Fang Deng Warren G Dominy Scott Smiley Peter J Bechtel 《Aquaculture Research》2013,44(9):1438-1446
The objectives of this study were to investigate the nutritional value of skate meal and sablefish viscera meal from Alaskan fishery processing and to ascertain their suitability as replacements for pollock fishmeal in diets for Pacific threadfin (Polydactylus sexfilis). Test diets were made by replacing 50% or 100% protein from fish meal in the control diet with skate or sablefish viscera meal. The test diets and a commercial feed were each assigned to four tanks with eight juvenile fish (9.7 g) per tank in an indoor flow‐through culture system. After 6 weeks, Pacific threadfin fed skate meal‐50% and ‐100% substituted diets exhibited similar weight gains (374%; 369%) and feed conversion ratios (1.29; 1.27) as those fed the control diet (345%; 1.30 respectively) (P > 0.05). In contrast, Pacific threadfin fed the sablefish viscera meal‐50% substituted diet exhibited significantly lower weight gain (112%) than fish fed the control diets (P < 0.05). The fish fed the control diet and skate meal substituted diets also achieved significantly higher (P < 0.05) weight gain than those fed the commercial feed (288%). In conclusion, skate meal can fully replace the commercial fishmeal in a Pacific threadfin diet without adversely effecting growth performance. 相似文献