小麦矮秆基因Rht-8对株高和其它农艺性状的遗传效应

分析矮秆基因Rht-8的遗传力及其对小麦株高及相关农艺性状的影响。利用三个小麦品种晋麦47、西峰20、丰产3号分别与Rht-8的供体亲本济宁13杂交,以其F₂分离群体分析Rht-8的遗传效应。结果表明,丰产3号和济宁13后代的遗传力最高（74.32％）,西峰20、晋麦47与济宁13后代的遗传力分别为69.49%、67.60%。Rht-8在西峰20和济宁13的F₂中具有较强的效应,株高和穗下节分别降低了30.26％和19.20％。在丰产3号和晋麦47与济宁13的F₂中,株高和穗下节分别降低了27.14%和26.15%、14.86 %和14.59%。Rht-8减少了有效分蘖个数,对其他性状则无明显的不利影响。相关性分析表明株高与分蘖数显著正相关（r为0.415,0.355,0.489）,与穗下节显著正相关（r为0.408,0.450,0.500）;株高与穗长、每穗小穗数、穗粒数没有显著相关性。     

Effect of wheat and rice straw biochar produced at different temperatures on maize growth and nutrient dynamics of a calcareous soil

The objective of this work was to study the effect of different biochar on alkaline calcareous soil, inherently low in soil organic carbon and fertility. Experiments were conducted in laboratory and greenhouse. Biochar was produced from wheat and rice straws at pyrolysis temperatures of 300°C, 400°C and 500°C (denoted as WSB300, WSB400, WSB500, RSB300, RSB400 and RSB500, respectively). In the first experiment, soil was incubated with biochar (1.0 % w/w) for up to 50 weeks. The results indicate that, WSB300 caused a significant decrease in soil pH and increased the CEC and nutrients (N, P and K) after 50 weeks of incubation. In the second experiment, maize plants were grown in pots containing calcareous soil amended with WSB and RSB for 60 days the results revealed that the application of WSB300 caused a significant increase in shoot (36%) and root (38%) dry matters over the respective control. Moreover, the highest nutrient concentrations (N and P) in shoot and root were observed with the WSB300 compared to other treatments. Therefore, it is concluded that application of wheat straw biochar produced at low temperature (WSB300) could be successfully used to improve soil properties and growth of plants in calcareous soils.     

Improved productivity and zinc content for maize grain by different zinc fertilization techniques in calcareous soils

Scientific management of nutrients along with several other crop management practices are required for sustainable production of maize (Zea mays L.). Zinc (Zn) status of maize grown in Potohar plateau, Pakistan was monitored. A two-year field study was conducted at two sites to assess the yield of maize cultivars, i.e., hybrid (cv. NARC-2704) and local (cv. Agaiti-2002) and Zn requirement of leaves and grain using various Zn application methods. Zinc was applied by three ways, i.e., broadcast and band placement each at 3, 6 and 9 kg Zn ha^?1; and foliar at 0.5, 1.0 and 1.5 kg Zn ha^?1 along with recommended basal fertilization. Cultivars' response varied to Zn rates, application techniques and sites. The maximum increase in grain yield (two-year mean) at NARC site was: broadcast – hybrid, 17% and local, 13%; band placement – hybrid, 18% and local, 16%; and foliar – hybrid, 15% and local, 13%. Corresponding response at Pindi Gheb site was: broadcast – hybrid, 20% and local, 16%; band placement – hybrid, 21% and local, 17%; and foliar – hybrid, 17% and local, 15%. Zn concentration in leaves and grain of both cultivars also increased to varying extent as a result of applied Zn rates and techniques. Fertilizer Zn requirement for near-maximum grain yield (kg ha^?1) was: broadcast – hybrid, 4.6 and local, 1.9; band placement – hybrid, 1.8 and local, 1.5; and foliar – hybrid, 0.28 and local, 0.26.     

Response of Sunflower to Sulfur Rate and Time of Application under Two Tillage Systems in a Silty Clay Soil of Dera Ismail Khan Pakistan

ABSTRACT

Sulfur (S) availability is a characteristic of conservation tillage. We studied the effects of S on sunflower yield and fatty acid profile under conventional and conservation tillage in silty clay soil of D.I. Khan, Pakistan. Conventional tillage consisted of disk plowing followed by tiller and rotavator, while conservation tillage comprises tiller and disc harrowing. Treatments comprise six sulfur levels (S₁ = 0, S₂ = 20 kg S ha^?1 at sowing, S₃ = 10 kg S ha^?1 at sowing +10 kg S ha^?1 25 days after sowing (DAS), S₄ = 40 kg S ha^?1 at sowing, S₅ = 20 kg S ha^?1 at sowing + 20 kg S ha^?1 25 DAS, and S₆ = 20 kg S ha^?1 at sowing + 10 kg S ha^?1 25 DAS + 10 kg S ha^?1 50 DAS) replicated thrice. After 2 years of experimentation, soil samples were collected (from 0 to 0.30 m depth) for organic matter (OM), total soil N (TSN), and available sulfur analysis. Conservation tillage significantly increased OM, TSN, and S contents in 0–0.30 m soil compared to conventional tillage. Likewise, sunflower plants showed higher achene yield, better fatty acid profile, and net economic returns in conservation tillage than in conventional tillage. Application of 20 kg S ha^?1 at sowing and 10 kg S ha^?1 at each 25 and 50 DAS recorded significantly higher achene yield, higher oil, and linoleic acid contents; however, oleic and oleic/linoleic ratio did not increase with higher S rates. Conservation tillage was effective in increasing OM, TSN, and available S besides increasing yield and economics in silty clay soil.     

Faba bean (Vicia faba L.) varieties reveal substantial and contrasting organic phosphorus use efficiencies (PoUE) under symbiotic conditions

Background

The excessive use of inorganic P (Pi) in soils is alarming as it is causing numerous environmental problems and may lead to the depletion of rock phosphate reserves earlier than expected. Hence, to limit the over-dependence on Pi, there is the need to investigate organic phosphorus (Po), which is the dominant P form of soil P pool, as an alternate P source for plant growth.

Aim

The present study seeks to investigate organic P use efficiency of eight varieties of faba bean grown symbiotically.

Methods

The plants were grown in pots (6 kg soil) under greenhouse condition with three P source, namely, phytic acid (organic P, Po), KH₂PO₄ (inorganic P, Pi), and no-P. The P was applied at the rate of 1.79 g kg⁻¹ soil.

Results

The plants grown with Po and Pi produced similar amounts of root, shoot, and total dry matters. Despite producing statistically similar dry matters, P uptake by Pi-fertilized plants was twofold higher than by Po-fertilized plants. Meanwhile, Pi differed significantly from Po in terms of nodulation characteristics such as nodule dry biomass and individual nodule dry biomass. However, Po varied significantly from Pi in P utilization and acquisition efficiencies. Principal component analysis of Pi and Po revealed no significant variation and close association, confirming the nonsignificant differences between the two P treatments. Among the varieties tested, Tiffany tended to accumulate more dry matter, coupled with highest organic P utilization efficiency (0.48 g mg⁻¹) as well as the highest organic P beneficiary factor (80%).

Conclusion

These results provide a solid basis for further comparisons at physiological, biochemical, and molecular levels between Tiffany (Po-efficient) and Fuego (Po-inefficient) varieties, offering deep insights into and making it easier to understand the mechanisms that allow soil Po to be utilized under symbiotic conditions.     

Adsorption of Lead,Cadmium, and Nickel on Benchmark Soils of Pakistan

Eurasian Soil Science - Adsorption and desorption reactions at the solid phase–solution interface, play a significant role in controlling metal concentrations in soil solution and metal...     

Evaluation of protein digestibility-corrected amino acid score method for assessing protein quality of foods

The current concepts of protein quality evaluation were reviewed. A detailed examination of existing animal assays and more promising amino acid scoring methods has been carried out by an Ad Hoc Working Group on Protein Quality Measurement for the Codex Committee on Vegetable Proteins during the last 5 years. Several factors such as inadequacies of protein efficiency ratio (PER, the poorest test) and other animal assays, advancements made in standardizing methods for amino acid analysis and protein digestibility, availability of data on digestibility of protein and individual amino acids in a variety of foods, and reliability of human amino acid requirements and scoring patterns were evaluated. On the basis of this evaluation, amino acid score, corrected for true digestibility of protein, was recommended to be the most suitable routine method for predicting protein quality of foods for humans. Amino acid scores corrected for true digestibility of protein (as determined by rat balance method) were termed "protein digestibility-corrected amino acid scores." A detailed method for the determination of the protein digestibility-corrected amino acid score was proposed, and information about the range of scores to be expected in foods or food products was provided in the present investigation. The protein digestibility-corrected amino acid score method is a simple and scientifically sound approach for routine evaluation of protein quality of foods. Accuracy of the method would, however, be confirmed after validation with growth or metabolic balance studies in humans.     

Integrated Weed Management Through Tillage and Herbicides for Wheat Production in Rice-Wheat Cropping System in Northwestern Pakistan

Conservational tillage (CT) in combination with broad spectrum herbicide may be more efficient and economical in controlling weeds,reducing cost of cultivation,and enhancing wheat yield.Field experimen...     

Impact of Tillage and Herbicides on Weed Density,Yield and Quality of Cotton in Wheat Based Cropping System

Conservation tillage may improve yield of cotton in addition to improvement in soil quality if practiced for longer period. However, the practice may not be productive in short-term particularly when severe weeds are infesting the crops such as Cynodon dactylon, Conyza canadensis, Tribulus terrestris, and Cyperus rotundus, etc. Recent studies indicate that conventional tillage (CT) is more productive than zero tillage (ZT)/reduced tillage (RT). Performance of cotton under three tillage systems, viz., ZT, RT and CT; and five herbicides, i.e., haloxyfop-R-methyl 10.8 EC (108 g a.i. ha^?1), lactofen 24 EC (168 g a.i. ha^?1), haloxyfop 10.8 EC + lactofen 24 EC, hand weeding, and weedy check were evaluated during 2010-2011 at Gomal University, D.I. Khan, Pakistan, to explore the best management option for effective weed control, enhanced yield and quality of cotton grown after wheat. The results revealed that hand weeding and Haloxyfop as post emergence alone or in combination with Lactofen reduced weed density to the minimum irrespective of the tillage systems. Excessive rainfall and cooler temperature limited cotton growth and yield in 2010. The adverse weather conditions had more adverse effect on boll weight under ZT and RT than CT. Haloxyfop + lactofen produced higher seed cotton yield in RT than ZT, however, it could not exceed CT. Broad-spectrum herbicides × CT produced the highest number of bolls/plant, boll weight and seed cotton yield. Fiber quality and net returns were also the highest in broad-spectrum herbicides × CT. In conclusion, broad-spectrum herbicides under CT were more productive in wheat based cropping system on silty clay soil of D.I. Khan.     

Effect of pre-extraction on soda-anthraquinone (AQ) pulping of rice straw

The effect of hot-water and alkaline pre-extraction of rice straw on soda-anthraquinone pulping was carried out. The pre-extraction with hot water at 150 °C for 1 h dissolved 34.7% biomass and the pre-extracted liquor comprised of 16.6% sugars, 6.7% lignin, 6.6% acetic acid and other unknown products. But the pre-extraction with 1% NaOH at 100 °C for 1 h dissolved 10.2% sugars, 5.1% lignin and 10% acetic acid from rice straw. Pre-extracted rice straw was cooked by soda-anthraquinone process with varying alkali charges. The pulp from pre-extracted rice straw was low in kappa number with reduced pulp yield. The drainage resistance (°SR) improved obviously on pre-extraction of rice straw. Pulp strength properties such as the tensile index and the burst index were found to be lower, but the tear index was higher both with hot-water and alkaline pre-extraction. After bleaching, the gaps of the overall pulp yield and strength properties between pre-extracted and non-extracted rice straw became narrower. The alkaline pre-extraction showed improved yield and properties compared with hot-water pre-extracted rice straw.