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Evaluation of Assembly Strategies Using RNA-Seq Data Associated with Grain Development of Wheat (Triticum aestivum L.)  [PDF]
Huai-Zhu Li, Xiang Gao, Xiao-Yan Li, Qi-Jiao Chen, Jian Dong, Wan-Chun Zhao
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0083530
Abstract: Wheat (Triticum aestivum L.) is one of the most important crops cultivated worldwide. Identifying the complete transcriptome of wheat grain could serve as foundation for further study of wheat seed development. However, the relatively large size and the polyploid complexity of the genome have been substantial barriers to molecular genetics and transcriptome analysis of wheat. Alternatively, RNA sequencing has provided some useful information about wheat genes. However, because of the large number of short reads generated by RNA sequencing, factors that are crucial to transcriptome assembly, including software, candidate parameters and assembly strategies, need to be optimized and evaluated for wheat data. In the present study, four cDNA libraries associated with wheat grain development were constructed and sequenced. A total of 14.17 Gb of high-quality reads were obtained and used to assess different assembly strategies. The most successful approach was to filter the reads with Q30 prior to de novo assembly using Trinity, merge the assembled contigs with genes available in wheat cDNA reference data sets, and combine the resulting assembly with an assembly from a reference-based strategy. Using this approach, a relatively accurate and nearly complete transcriptome associated with wheat grain development was obtained, suggesting that this is an effective strategy for generation of a high-quality transcriptome from RNA sequencing data.
Effect of Environmental Changes on Phytic Acid Content of Wheat (Triticum aestivum)  [PDF]
Talat Mahmood,Tabassum Hameed,Nouman Rashid Siddiqui,Amir Mumtaz
Pakistan Journal of Nutrition , 2010,
Abstract: Wheat (Triticum aestivum) is one of the most important food grain crops in all South Asian countries especially in India and Pakistan. These countries have diversifying soil and climatic conditions inserting measurable effect on nutritional as well as anti-nutritional parameters of wheat. Wheat varieties included in this study are collected from different agro-ecological zones of Pakistan. Myoinositol hexa-phosphate (phytic acid) one of major anti-nutritional factors wheat. Phytic acid of collected samples was determined to facilitate the crop breeders and agronomists, so that they would also consider this factor while conducting research works. It was observed that wheat varieties showed different levels of phytic acid at different locations. At one location (Islamabad), a variety (Pari-73) showed the highest value of Phytic acid (1.343%) and at other location (Faisalabad), same variety the showed lowest phytic acid (0.74%). This maximum variability (44%) also indicated that there was significant effect of change in location on phytic acid contents of wheat varieties. It is mainly due to presence of available phosphorus reserves in soil as phytate has direct relation to soil phosphorus.
Line × Tester Mating Design Analysis for Grain Yield and Yield Related Traits in Bread Wheat (Triticum aestivum L.)  [PDF]
Zine El Abidine Fellahi,Abderrahmane Hannachi,Hamenna Bouzerzour,Ammar Boutekrabt
International Journal of Agronomy , 2013, DOI: 10.1155/2013/201851
Abstract: Nine bread wheat (Triticum aestivum L.) genotypes were crossed in a line × tester mating design. The 20 F1's and their parents were evaluated in a randomized complete block design with three replications at the Field Crop Institute-Agricultural Experimental Station of Setif (Algeria) during the 2011/2012 cropping season. The results indicated that sufficient genetic variability was observed for all characters studied. A899?× Rmada, A899?× Wifak, and A1135?× Wifak hybrids had greater grain yield mean than the parents. A901 line and the tester Wifak were good combiners for the number of grains per spike. MD is a good combiner for 1000-kernel weight and number of fertile tillers. HD1220 is a good general combiner to reduce plant height; Rmada is a good general combiner to shorten the duration of the vegetative growth period. A901?× Wifak is a best specific combiner to reduce plant height, to increase 1000-kernel weight and number of grains per spike. AA × MD is a best specific combiner to reduce duration of the vegetative period, plant height and to increase the number of kernels per spike. A899?× Wifak showed the highest heterosis for grain yield, accompanied with positive heterosis for the number of fertile tillers and spike length, and negative heterosis for 1000-kernel weight and the number of days to heading. , ? low ratios and low to intermediate estimates of h2ns supported the involvement of both additive and nonadditive gene effects. The preponderance of non-additive type of gene actions clearly indicated that selection of superior plants should be postponed to later generation. 1. Introduction Bread wheat (Triticum aestivum L.) is an important staple food in Algeria. This crop ranks third after durum wheat (Triticum durum Desf.) and barley (Hordeum vulgare L.), with a yearly cropped area of 0.8 million hectares, representing 24.2% of the 3.3 million hectares devoted to small grain cereals. Algeria imported 3.0 million tons of bread wheat in 2010/2011, to remedy the decline in the domestic production and to build stocks to meet the needs. Increasing wheat production can be achieved by application of improved agronomic technics, developing and adopting high yielding varieties. Major emphasis, in breeding program, is put on the development of improved varieties with superior qualitative and quantitative traits and resilience to abiotic stresses. In fact, genetic improvement in bread wheat, having better tolerance against terminal heat and water stress, has a good promise to improve grain yield average and total wheat production. However to breed high
The Contents of Microelements and Exogenous Amino Acids in Spring Wheat (Triticum aestivum L.) Grain after Municipal Sewage Sludge Fertilization  [cached]
Krzysztof Gondek,Michal Kopec,Tomasz Glab
Journal of Agricultural Science , 2012, DOI: 10.5539/jas.v4n12p294
Abstract: The research was conducted to assess the effect of municipal sewage fertilization on the contents of microelements and exogenous amino acids in grain of spring wheat (Triticum aestivum L.). The investigations were conducted as a field experiment in the years 2005-2007 on the silt loam soil classified as Stagnic Gleysol. The experimental design comprised 5 treatments of fertilization in four replications: unfertilized control (0), mineral materials (M), pig manure (PM), municipal sewage sludge from mechanical-biological treatment plant (SS1) and municipal sewage sludge from biological treatment plant (SS2). On the basis of obtained results it was stated that difficult access of plants to nitrogen supplied with sewage sludge may considerably determine the crop yield and its quality, particularly in the first year after the fertilizers application. Applied doses of sewage sludge did not affect significantly the contents of analyzed microelements or exogenous amino acids. Irrespective of applied fertilization, the microelements which reduced fodder value of spring wheat were copper and manganese, whereas protein concentrations were determined by lysine content.
Combining ability analysis for grain filling duration and yield traits in spring wheat (Triticum aestivum L. em. Thell.)
Kamaluddin,;Singh, Rishi M.;Prasad, Lal C.;Abdin, Malik Z.;Joshi, Arun K.;
Genetics and Molecular Biology , 2007, DOI: 10.1590/S1415-47572007000300018
Abstract: a diallel analysis of wheat (triticum aestivum l. em. thell) parents (n = 11) and their f1 (n = 55) and f2 (n = 55) offspring was carried out for the following four traits: grain filling duration (gfd), gfd for growing degree days (gdd), 1000 seed weight and seed yield per plant. analysis of variance for general combining ability (gca) and specific combining ability (sca) displayed significant f1 and f2 general and specific combining ability effects for the four traits studied. for all the traits the gca effects were relatively more important than the sca effects, indicating that additive genetic effects were predominant. crosses displaying high sca effects for grain filling duration, seed weight and yield were observed to be derived from parents having various types of gca effects (high x high, high x low, low x low and medium x low). the single seed descent method can be applied to exploit additive gene effects whereas dominance gene effects could be valuable in hybrid wheat breeding programs. among the parents, genotypes from the international maize and wheat improvement center (centro internacional de mejoramiento de maíz y trigo, cimmyt) as well as south asia were found to be superior general combiners for grain filling duration. likewise, crosses involving diverse parents from cimmyt and south asia showed significant sca effects for grain filling duration and other traits.
Effect of Irrigation Regimes on Grain Growth Indices of Three Winter Wheat (Triticum aestivum L.) Cultivars Under the Iranian Conditions  [PDF]
H. Dehghanzadeh jazy,M.R. Khajeh poor,H.H. Sharif Abad,A. Soleimani
Asian Journal of Plant Sciences , 2009,
Abstract: An experiment was conducted during 2004-2006 at the Agricultural Research Station, Islamic Azad University, Khorasgan Branch, Isfahan, Iran. The purpose of this study is to study the effect of deficit irrigation regimes on the grain growth rate and the effective grain filling period of the bread wheat (Triticum aestivum L.) cultivars. A split plot layout arranged in randomized complete block design with four replications was used. Irrigation regimes (irrigation after 70 mm (I1), 90 mm (I2) and 110 mm (I3) cumulative evaporation from class A evaporation pan) were considered as the main plot and three wheat cultivars (Mahdavy, Ghods and Roshan-Backcross) as subplots. The I1 and I2 did not differ significantly for grain growth rate (GGR) and effective grain filling period (EGFP). Delay in irrigation from the I2 to the I3 caused significant reduction in grain growth rate and effective grain filling period. Trend of changes in grain weight was similar in the I1 and the I2. In all samplings, delay in irrigation from the I2 to the I3 reduced grain weight. Cultivars differed significantly in respect to grain growth. The effect of grain growth rate on 1000-grain weight was more pronounced than effective grain filling period. Obtained results indicate that irrigation after 90 mm cumulative evaporation from class (A) evaporation pan might be suitable for the grain weight of winter wheat under similar the conditions to this experiment where irrigation water during grain filling period is not abundant.
Correlation Analysis of some Growth, Yield, Yield Components and Grain Quality of Wheat (Triticum aestivum L.)
MB Sokoto, IU Abubakar, AU Dikko
Nigerian Journal of Basic and Applied Sciences , 2012,
Abstract: Field experiments were conducted during the 2009/2010 and 2010/2011 dry seasons at the Fadama Teaching and Research Farm of the Usmanu Danfodiyo University, Sokoto, in the Sudan Savanna ecological zone of Nigeria. The farm is located on latitude 130011N; longitude 50151E and at an altitude of about 350 m above sea level. The study was aimed at investigating the correlation between some growth, yield, yield components and grain quality of wheat (Triticum aestivum L.). The treatments consisted of factorial combination of water stress at three critical growth stages which was imposed by withholding water (at Tillering, Flowering, Grain filling) and Control (No stress), two varieties (Star 11 TR 77173/SLM and Kuaze/Weaver) and four sowing dates (21st November, 5th December, 19th December and 2nd January) laid out in a split plot design with three replications. Simple correlation coefficient of different crop parameters and grain yield indicated that most of the agrophysiological crop parameters viz. plant height, number of tiller m-2, Leaf Area Index (LAI), Net Assimilation Rate (NAR), Crop Growth Rate (CGR), number of spike m-2, spike length, spikelets per spike, number of grain per spike, 1000-grain weight, total aerial phytomass and harvest index had significant positive correlation with grain yield in both seasons and combined and this indicate their importance in yield determination. Protein and gluten content had varying levels of correlation in both seasons and combined. An over all, it is logical to conclude that spike m-2, number of spikelets per spike, grain per spike, total aerial phytomass yield, grain yield, harvest index and 1000-grain weight are the major contributors towards grain yield since these characters had high correlation. Thus, direct selection of these characters should be major concern for increased grain yield and grain quality of wheat.
Characters of Rachis and Grain within Different Spike Parts in Spike Hetero Branching Wheat (Triticum aestivum L.)  [cached]
Lanfei Zhao,Weidong Zhang,Qingrong Gao,Anfei Li
Journal of Agricultural Science , 2012, DOI: 10.5539/jas.v4n12p106
Abstract: Spike hetero branching wheat (Triticum aestivum) (SHBW) has one main rachis, but has branched rachises at lower parts of main rachis. This type of spike could increase greatly grain number by bearing grain in branching rachis. In this study, field experiments were conducted at three locations in Huanghuai wheat zone during two growing seasons (2008-2010). The rachises length, node number, grain number, and grain weight were investigated within five different spikes parts. The results showed that the proportion of the length of upper no-branching part to that of lower branching part within the main rachis varied from 0.49-0.99; The coefficient of variations (CVs) of main rachis length, node number within main rachis and grain number and thousand grain weight within the upper part of main rachis were 9.78%, 8.49%, 21.73% and 17.32%, respectively, but CVs of these traits within the branched rachises were 54.45%, 37.21%, 36.80%, and 19.45%, respectively. This indicated that the morphological characters within branched rachises were more easily influenced by external environments. Grain number in the whole spike and average branched rachises length were unstable under various environments and the two traits should be regarded as the main choice factors in future breeding selection in SHBW.
Estimation of Heterosis for Grain Yield and its Related Traits in Wheat (Triticum aestivum L.) under Leaf Rust Conditions  [PDF]
Fida Hussain,Muhammad Ashraf,Syed Sadaqat Mehdi,Malik Tanveer Ahmad
Journal of Biological Sciences , 2004,
Abstract: Eight bread wheat (Triticum aestivum L.) cultivars were crossed in a diallel fashion and evaluated for heterosis in F1 generation for grain yield and other economic traits under leaf rust conditions. Highly significant differences were found among genotypes for all the traits studied. Significant positive heterosis and heterobeltiosis was observed for grain yield per plant in almost all crosses. Estimates for positive significant heterosis over mid and better parents for plant height were 68 and 32% of total crosses where as 44 and 35 crosses gave significant positive increased tillers per plant over their mid and better parents, respectively. Positive and significant heterotic effects were measured as 11.61, 61.90, 30.67, 2.3, 51.89, 126.64, 111.71 and 45.91% from crosses SA42 x Nacozari, MH 97 x Crow, Parula x Chenab70, Crow x Nacozari, Crow x Chenab70, SA42 x Nacozari, MH97 x SA42 and Nacozari x Chenab for plant height, tillers per plant, grains per spike, spikelets per spike, grain weight, grain yield, biological yield per plant and harvest index, respectively.
Competition Increases Sensitivity of Wheat (Triticum aestivum) to Biotic Plant-Soil Feedback  [PDF]
W. H. Gera Hol, Wietse de Boer, Freddy ten Hooven, Wim H. van der Putten
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0066085
Abstract: Plant-soil feedback (PSF) and plant competition play an important role in structuring vegetation composition, but their interaction remains unclear. Recent studies suggest that competing plants could dilute pathogenic effects, whereas the standing view is that competition may increase the sensitivity of the focal plant to PSF. In agro-ecosystems each of these two options would yield contrasting outcomes: reduced versus enhanced effects of weeds on crop biomass production. To test the effect of competition on sensitivity to PSF, we grew Triticum aestivum (Common wheat) with and without competition from a weed community composed of Vicia villosa, Chenopodium album and Myosotis arvensis. Plants were grown in sterilized soil, with or without living field inoculum from 4 farms in the UK. In the conditioning phase, field inocula had both positive and negative effects on T. aestivum shoot biomass, depending on farm. In the feedback phase the differences between shoot biomass in T. aestivum monoculture on non-inoculated and inoculated soils had mostly disappeared. However, T. aestivum plants growing in mixtures in the feedback phase were larger on non-inoculated soil than on inoculated soil. Hence, T. aestivum was more sensitive to competition when the field soil biota was present. This was supported by the statistically significant negative correlation between shoot biomass of weeds and T. aestivum, which was absent on sterilized soil. In conclusion, competition in cereal crop-weed systems appears to increase cereal crop sensitivity to soil biota.
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