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Biological nitrogen fixation of some groundnuts as affected by genotype and applied phosphorus at Samaru, northern Guinea Savannah of Nigeria
AI Gabasawa, AA Yusuf
Bayero Journal of Pure and Applied Sciences , 2012,
Abstract: Biological nitrogen fixation (BNF), brought about by both free living soil microorganisms and their symbiotic associations with higher plants, is the major source of N input into agricultural systems. Groundnuts (Arachis hypogaea L.), in symbiosis with rhizobia, in their root nodules, fix atmospheric nitrogen (N2). A field trial was carried out at Samaru, Nigeria, in 2008 with a view to evaluate BNF potentials of five groundnut genotypes (SAMNUT 10, 11, 21, 22 and 23). Each genotype received four rates of P (0, 20, 40 and 60 P2O5 ha-1) in an RCBD with three replications. N-Difference method was employed in assessing the BNF of the genotypes. Nodulation performance of the genotypes was observed. Results of the study showed that SAMNUT 11 and 22 significantly recorded the highest nodulation, by number and weight. All the remaining genotypes statistically produced same nodule number. Moreover, the early maturing SAMNUT 21 fixed the highest (82 kg N ha-1) quantity of N2, while SAMNUT 11 (46 kg N ha-1) and 23 (31 kg N ha-1) were statistically similar and fixed the lowest N2. SAMNUT 11 and 22 were, therefore, found to significantly record the highest nodule number and weigh and SAMNUT 21 fixed the highest N2, and hence the highest BNF, indicating their genotypic desirability in terms of N2 addition to the soil environment, especially for subsequent crops.
Genotype x Environment interaction for quality traits in durum wheat cultivars adapted to different environments
M Taghouti, F Gaboun, N Nsarellah, R Rhrib, M El-Haila, M Kamar, F Abbad-Andaloussi, SM Udupa
African Journal of Biotechnology , 2010,
Abstract: The quality traits of durum wheat are important for the utilization by the industries. These traits may be influenced by genotype and interaction of genotype and environment (GxE). To evaluate the effects of genotype, environment and genotype x environment interaction on quality traits such as vitreousness, SDS sedimentation test, yellow pigment index, protein content and test weight, twelve Moroccan durum wheat cultivars representing a range of agronomic adaptation were tested in five locations representing a range of environments in three growing seasons. The results indicated significant effects of genotype, environment and GxE for all the quality traits. The extent of these effects differed; for SDS sedimentation volumes, yellow pigment and test weight, the component of variation due to genotype was larger than due to the environment, indicating the greater influence of genotypes on these traits. However, for vitreousness and protein content, the effect of environment was higher than the effect due to genotypes. Thus, these traits are controlled greatly by environmental effects than genetics. The variation due to GxE was higher than that of genotype for vitreousness and test weight, indicating high GxE interaction effect and less genotypic stability for these traits. For protein content, where the environmental effect was greater than that of genotype and GxE effect, multiple environmental trials are necessary in order to determine protein content of a cultivar. For other traits, preliminary evaluations can be done in one environment and good performing ones can be selected for multiple environmental trials.
Cadmium and Zinc Concentration in Grain of Durum Wheat in Relation to Phosphorus Fertilization, Crop Sequence and Tillage Management  [PDF]
Xiaopeng Gao,Cynthia A. Grant
Applied and Environmental Soil Science , 2012, DOI: 10.1155/2012/817107
Abstract: Field experiments were conducted at two locations in Manitoba, Canada, to determine the effect of crop rotation, phosphorus (P) fertilization and tillage on grain yield and grain concentrations of Cd and Zn in durum wheat (Triticum durum L.). Compared to conventional tillage (CT), reduced tillage (RT) management decreased grain Cd and increased grain yield and grain Zn in half of the site-years. The type of preceding crops of spring wheat-flax or canola-flax had little influence. Rate and timing of P application had little effect on grain Cd, but increasing P rate tended to decrease grain Zn. No interactive effect was detected among tested factors. Grain Zn was not related to grain Cd, but positively to other nutrients such as Fe, Mn, P, Ca, K, and Mg. Both grain Zn and Fe correlated positively with grain protein content, suggesting protein may represent a sink for micronutrients. The study suggested that the tillage management may have beneficial effects on both grain yield and quality. Phosphorus fertilizer can remain available for subsequent crops and high annual inputs in the crop sequence may decrease crop grain Zn. Understanding the environment is important in determining the impact of agricultural management on agronomic and nutrient traits. 1. Introduction Cadmium (Cd) accumulation in soils and cereal crops and its transfer to the human diet is a widespread problem around the world. Durum wheat (Triticum durum L.) is of particular concern because it accumulates more Cd than the other commonly grown cereals with accumulation increasing in the order of rye < barley < oats < bread wheat < durum wheat [1]. Cadmium concentration in durum wheat grain harvested on Canadian prairies have been reported to range from less than 50 to more than 300?μg kg?1 [2], at times exceeding the 200?μg kg?1 limit set by the Codex Alimentarius Commission [3]. In addition, approximately 2.1 × 106?ha durum wheat, which occupies 10% of worldwide durum production area, is grown in the western Prairie region of Canada [4]. Therefore, there is a desire in the Canadian farming industry to control the Cd levels in the durum grain, either by improved agricultural management practices [5] or by breeding low Cd-accumulating cultivars [6, 7]. Accumulation of metal elements in crop grains can be regulated by several physiological processes, including uptake from the soil solution, root-to-shoot translocation, and retranslocation into the grain during maturation. Zinc (Zn) and Cd are chemically similar and can compete for common transport mechanisms for uptake and translocation in
Epistasis and genotype-by-environment interaction of grain protein content in durum wheat
Bnejdi, Fethi;Gazzah, Mohamed El;
Genetics and Molecular Biology , 2010, DOI: 10.1590/S1415-47572010000100021
Abstract: parental, f1, f2, bc1 and bc2 generations of four crosses involving four cultivars of durum wheat (triticum durum desf.) were evaluated at two sites in tunisia. a three-parameter model was found inadequate for all cases except crosses chili x cocorit 71 at site sidi thabet and inrat 69 x karim at both sites. in most cases a digenic epistatic model was sufficient to explain variation in generation means. dominance effects (h) and additive x additive epistasis (i) (when significant) were more important than additive (d) effects and other epistatic components. considering the genotype-by-environment interaction, the non-interactive model (m, d, h, e) was found adequate. additive variance was higher than environmental variance in three crosses at both sites. the estimated values of narrow-sense heritability were dependent upon the cross and the sites and were 0%-85%. the results indicate that appropriate choice of environment and selection in later generations would increase grain protein content in durum wheat.
Estimates of Genotype x Environment Interactions and Heritability of Black Point in Durum Wheat  [cached]
Hasan KILI?,Abuzer SA?IR,Yunus BAYRAM
Notulae Scientia Biologicae , 2009,
Abstract: Experiments were carried out in four different locations with 14 durum wheat genotypes in two successful seasons of 1999- 2000 and 2000-2001. Black point disease of genotypes was evaluated by interactions of genotypes and environment as well as heritability (h2). It was found that black point disease affected differently in different locations and growing seasons. This indicates that the genotypes have different adaptation ability for traits studied in different locations. Heritability rate that variance analyzes accepted means squares calculated was found as phenotypic variance rate of genotypic variance was found as 49%. Variance of genotype x location x year was bigger than other variance components. Genotype x year variance was bigger than genotype x location variance too. The heritability of black point disease was founded moderate. In addition to one of factors on the black point disease genotype also environment x genotype interactions were found effective. According to evaluation of black point disease, the highest value was obtained from Sorgül (2.7%), Dicle-74 (2.56%) and Gidara-II (2.32%) varieties; the least value was obtained from Balcal -2000 variety (0.64%). Alternaria spp., Phoma sp., Fusarium spp., Helminthosporium spp., and Stemphylium spp., fungi were isolated from the grain affected by black point diseases.
Tillering of two wheat genotypes as affected by phosphorus levels
Fioreze, Samuel Luiz;Castoldi, Gustavo;Pivetta, Laércio Augusto;Pivetta, Laerte Gustavo;Fernandes, Dirceu Maxinimo;Büll, Leonardo Theodoro;
Acta Scientiarum. Agronomy , 2012, DOI: 10.4025/actasciagron.v34i3.13326
Abstract: tillering plays an important role in wheat yield potential and it is affected by genotype and environmental conditions. this work aimed to study the effects of phosphorus levels on tiller emergence, survival and contribution to yield potential of two wheat cultivars. the experiment was carried out under greenhouse conditions in botucatu, s?o paulo state, brazil. a 2 x 5 factorial randomized block design with four replications was applied. two wheat cultivars (iac 370 and iac 375) and five phosphorus levels (0, 150, 300, 450 and 600 mg dm-3) were evaluated in pots with 10 dm3 of a clayey oxisol. higher p levels increased tiller emergence, survival and yield, especially for secondary tillers. tiller abortion levels were higher in iac 370 cultivar whereas retention of formed tillers was higher in iac 375.
Effect of Rate and Times of Nitrogen Application on Accumulation and Remobilization Efficiency of Flag Leaf in Two Wheat Cultivars  [cached]
A. Bahrani,Z.Tahmasebi Sarvestani
Journal of Science and Technology of Agriculture and Natural Resources , 2007,
Abstract: Understanding the nitrogen remobilization by plant, in order to obtain cultivars with higher quality, has specific importance in plant physiology. In this experiment, a bread and a durum wheat cultivar, were treated with different rates and times of nitrogen application, by using split factorial on the basis of randomized complete block design with three replications at Shiraz region during 2001-2002. Main plots consisted of two levels of cultivars ( Falat and Yavaros) and sub plots included nitrogen (40, 80 and 160 (kg ha-1) and times of nitrogen application (T1= all N fertilizer at planting , T2= 1/2 at planting + 1/2 during stem elongation and T3= 1/3 at planting + 1/3 during stem elongation + 1/3 at heading stage). The results showed that there was a significant difference between cultivars in flag leaf nitrogen content at maturity stage, N remobilization and its efficiency from flag leaf to grains and also grain protein percentage. Durum wheat was more efficient in nitrogen remobilization and therefore, had a higher grain protein percentage. Increase in rates and times of nitrogen application had significant effect on most of the measured traits. There were significant interactions between cultivars, rates and times of N application, indicating that durum wheat was more efficient in N remobilization from flag leaf to the grain. It appeared that N remobilization efficiency was the important factor affecting the grain protein percentage. Also increases in yield are associated with corresponding decreases in wheat protein.
Accumulation of Dry Matter and Nitrogen in Durum Wheat During Grain Filling as Affected by Temperature and Nitrogen Rate
Laura Ercoli,Alessandro Masoni,Marco Mariotti,Iduna Arduini
Italian Journal of Agronomy , 2011, DOI: 10.4081/ija.2009.1.3
Abstract: Durum wheat (Triticum durum Desf.) is commonly grown in mediterranean conditions, where temperature stress during grain filling can limit productivity. This study was conducted to assess the effect of optimal and too high temperature during grain filling on the patterns of accumulation of dry matter and N of durum wheat plants grown at different levels of N fertilization. Two durum wheat varieties, Appio and Creso, were grown in controlled environment conditions and in pots with three rates of nitrogen fertilizer (not applied, normal amount, and high amount) and two air temperature regimes during grain filling (20/15 °C and 28/23 °C day/night). Results showed that the duration of the intervals between the main maturity stages within grain filling were both genotype-specific and temperature- dependent, while N rate did not modify the timing of grain development. The two genotypes responded to temperature by increasing the rate of development, but the thermal timing of development was unchanged with the two temperature regimes. The higher temperature reduced grain growth and increased N accumulation in grain. However, these effects were recorded only in fertilized plants. Nitrogen availability modified the growth of the plant during the whole cycle, in that increased N fertilizer at seeding resulted in a greater plant size at anthesis and in a greater accumulation rate of dry matter and N in grain during grain filling. Grain yield and kernel weight were better expressed at 20/15 °C, while grain protein concentration was favoured under the 28/23 °C temperature regime. Nitrogen fertilization increased the sensitivity of plants to high temperature. Thus, the role of N fertilization under heat stress may be more important than under optimal temperatures.
Accumulation of Dry Matter and Nitrogen in Durum Wheat During Grain Filling as Affected by Temperature and Nitrogen Rate  [cached]
Laura Ercoli,Alessandro Masoni,Marco Mariotti,Iduna Arduini
Italian Journal of Agronomy , 2009, DOI: 10.4081/ija.2009.1.3
Abstract: Durum wheat (Triticum durum Desf.) is commonly grown in mediterranean conditions, where temperature stress during grain filling can limit productivity. This study was conducted to assess the effect of optimal and too high temperature during grain filling on the patterns of accumulation of dry matter and N of durum wheat plants grown at different levels of N fertilization. Two durum wheat varieties, Appio and Creso, were grown in controlled environment conditions and in pots with three rates of nitrogen fertilizer (not applied, normal amount, and high amount) and two air temperature regimes during grain filling (20/15 °C and 28/23 °C day/night). Results showed that the duration of the intervals between the main maturity stages within grain filling were both genotype-specific and temperature- dependent, while N rate did not modify the timing of grain development. The two genotypes responded to temperature by increasing the rate of development, but the thermal timing of development was unchanged with the two temperature regimes. The higher temperature reduced grain growth and increased N accumulation in grain. However, these effects were recorded only in fertilized plants. Nitrogen availability modified the growth of the plant during the whole cycle, in that increased N fertilizer at seeding resulted in a greater plant size at anthesis and in a greater accumulation rate of dry matter and N in grain during grain filling. Grain yield and kernel weight were better expressed at 20/15 °C, while grain protein concentration was favoured under the 28/23 °C temperature regime. Nitrogen fertilization increased the sensitivity of plants to high temperature. Thus, the role of N fertilization under heat stress may be more important than under optimal temperatures.
Remobilization of Dry Matter and Nitrogen in Maize as Affected by Hybrid Maturity Class
Silvia Pampana,Laura Ercoli,Alessandro Masoni,Iduna Arduini
Italian Journal of Agronomy , 2007, DOI: 10.4081/ija.2009.39
Abstract: The length of the growing cycle is one of the most important traits determining hybrid adaptability to the environment. The objective of this research was to compare in a field trial the pattern of dry matter and nitrogen accumulation and remobilization of four commercial maize hybrids belonging to FAO maturity group 400, 500, 600 and 700. The duration of the periods emergence-silking and silking-physiological maturity increased with the increase of hybrid maturity class. Silking occurred 6 days later in the latest maturing hybrid than in the earliest one, and physiological maturity 21 days later. Hybrids differed for biomass production at silking and at physiological maturity. At silking, plant dry weight and leaf area increased with hybrid maturity, owing to greater leaves and stalks. The lengthening of the period emergence-silking allowed a greater accumulation of assimilates in the plant, thus increasing the source of remobilization in the following period. The increase of the length of the period silking-maturity from hybrid 400 to hybrid 700 brought to an increase of dry matter accumulation coupled to a reduction of dry matter remobilization. Increases in hybrid maturity class resulted also in an increase of post-silking N uptake and N remobilization from vegetative plant parts. Thus, the longer period silking-maturity was associated with an increased photosynthetic activity of the plant, which hampered the rate of leaf senescence and deterred the mobilization of reserve carbohydrates for grain filling. Conversely, the longer was the hybrid cycle, the greater was the quantity of both N uptake from soil and remobilized N from vegetative plant parts.
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