四倍体小麦物种二粒小麦、硬粒小麦和波兰小麦的蜡质蛋白和直链淀粉含量

淀粉是禾谷类胚乳的主要成份。它含有两种多糖：具有线性结构的直链淀粉和具有网状结构的支链淀粉。在多数禾谷类作物中，直链淀粉与支链淀粉的比率为20～30％：70～80％。因为淀粉的生化性质取决于该比率，所以它非常重要。所得的‘蜡质淀粉’含直链淀粉很少或者几乎不含直链淀粉。

45S rDNA在小麦及其近缘物种染色体上的分布

将染色体C-分带和原位杂交技术相结合,系统研究了45S rDNA在栽培一粒小麦、野生二粒小麦、普通小麦、大麦、簇毛麦、硬簇麦、六倍体燕麦及鹅观草等物种染色体上的分布情况。这些物种染色体的次缢痕区都有45S rDNA位点,某些非随体染色体上也有45S rDNA位点分布。以小麦—鹅观草1Rk#1二体附加系为材料,通过顺序C分带-FISH技术首次将一个45S rDNA定位到1Rk#1染色体短臂末端。

部分小麦近缘物种材料的白粉病抗性鉴定

鉴定了170份小麦近缘物种材料苗期对北京地区流行的小麦白粉菌小种的抗性表现,包括引自美国和欧洲的斯卑尔脱小麦81份,密穗小麦27份,中国的西藏半野生小麦4份,和引自 CIMMYT 的人工合成六倍体小麦58份。结果表明,3份斯卑尔脱小麦表现抗病,它们是瑞士品种 Hubel 和 Lueg 以及德国的原始品种69Z6.245(编号 PI348085)。人工合成六倍体小麦中有19份材料表现高抗至免疫。密穗小麦材料中有2份(即美国材料 DN-2263和 Coda)表现抗病。4份西藏半野生小麦苗期都不抗小麦白粉病。

低温胁迫对小麦族物种抗寒生理的影响

小麦野生近缘物种是小麦品种改良的重要基因库,可为小麦抗寒力的提高提供丰富的基因资源。以抗寒性较好的三芒山羊草、冰草和强冬性小麦品种M808为试材,以春小麦材料中国春为对照,研究了低温处理对小麦族物种抗寒生理指标的影响。结果表明:低温胁迫下,所有材料相对电导率均呈现上升趋势,中国春上升最快,96h后达到90%,M808次之,而三芒山羊草和冰草相对较慢;可溶性蛋白含量在24h内变化不显著,随着低温胁迫时间的延长,三芒山羊草和冰草上升趋势较为明显,72h时达到峰值并开始下降;脯氨酸含量较未胁迫时有很大幅度的提高,96h后达到25~30μgFW.g-1的范围,三芒山羊草和冰草提高程度明显高于小麦材料;在相同的处理时间下,三芒山羊草和冰草的SOD活性也高于小麦材料;低温胁迫初期所有材料MDA含量迅速增加,24h后平缓上升,72h达到峰值,约90nmol.g-1,随后呈现下降趋势;可溶性糖含量低温胁迫初期有下降趋势,24h以后有所提高。综合分析发现三芒山羊草、冰草和冬小麦米808相应指标变化明显比春小麦更倾向于提高抗寒水平的方向发展,而三芒山羊草和冰草的抗寒生理基础要强于冬小麦品种M808。这些将为小麦族抗寒材料的发掘和抗寒生理机制的明确提供重要参考。

小麦属物种ω-醇溶蛋白序列的克隆与分析

为了挖掘ω-醇溶蛋白在小麦品质育种中的潜力,利用2对引物采用基因组PCR方法分别从阿拉拉特小麦（Triticum timopheevi Zhuk.var.araraticum）、栽培二粒小麦（Triticum turgidum ssp.dicoccon）、提莫菲维小麦（Triticum timopheevi）、栽培一粒小麦（Triticum monococcumssp.monococcum）和野生一粒小麦（Triticum monococcum var.boeoticum）5个小麦属物种中克隆出ω-醇溶蛋白序列,并对其进行序列分析。结果表明,本研究共克隆到6条新的ω-醇溶蛋白序列,归属于ARH、ATN和TRQ三种类型。这些新的ω-醇溶蛋白序列的长度为927~1 095bp。在这6个序列中,除KR082150拥有两个甲硫氨酸（Met）外,其余的均缺少含硫氨基酸。进化分析表明,本研究获得的6条ω-醇溶蛋白序列聚在了2个主要的分支,其中N端第一个氨基酸为丙氨酸（Ala）的ω-醇溶蛋白聚在了一个大的分支中,而TRQ类型的则聚在了另一个分支中。

小麦近缘物种通用标记的开发及应用

随着小麦远缘杂交和染色体工程的深入开展,小麦近缘物种的部分优异性状已被导入小麦,极大地丰富了普通小麦的遗传基础。然而,目前可用于检测小麦背景中近缘物种的通用分子标记还非常缺乏。本研究利用生物信息学手段筛选小麦A、B和D染色体组上相关基因,通过综合分析基因结构和不同内含子长度,在长度适宜的内含子上下游外显子保守序列处设计引物,以13份小麦为对照,以17份小麦近缘物种和15份小麦-近缘物种杂交种质等为材料,进行PCR扩增验证,开发了25个能检测小麦近缘物种的通用标记,对筛选鉴定小麦近缘物种、小麦-近缘物种杂交种质以及选育含外缘物种血缘的小麦品系(种)均具有重要意义。

Hybrid Effects on the Release of Phytosiderophores in Winter Wheat (Triticum aestivum)

Fe (iron) deficiency is an important nutritional problem particularly in crop plants grown on calcareous soils. Phytosiderophore (PS) release has been suggested to be linked to the ability of graminaceous species and genotypes to overcome Fe_deficiency chlorosis. Thus, enhancing PS release is a critical step to improve Fe nutrition of plants grown on Fe stressed soils. The heterosis of PS release rate in common wheat was studied by analyzing PS release from roots of three hybrids and their four parents grown in Fe_deficiency nutrient solution under controlled environmental conditions. PS release rates were determined at two or three day intervals after onset of Fe_deficiency symptoms by the measurement of Fe mobilizing capacity of root exudates from freshly precipitated FeⅢ hydroxide. High amounts of phytosiderophores were released from the roots of all wheat genotypes under Fe_deficiency, and the amount progressively increased with the development of Fe_deficiency chlorosis. The results revealed that the hybrids had more sensitive feedback systems which secreted more phytosiderophores under Fe_deficiency than their parents. By analyzing the relationship between each hybrid and its parents, it was also found that the parents should be selected on the basis of the rate of PS release and the combining ability by using the heterosis to improve Fe utilizability of crop plants.

Cytological and Molecular Identification of Alien Chromatin in Giant Spike Wheat Germplasm

Alien chromosomes of twelve giant spike wheat germplasm lines were identified by C-banding, genomic in situ hybridization (GISH), sequence characterized amplified region (SCAR), and random amplified polymorphic DNA (RAPD). All lines showed a chromosome number of 2n = 42, five of them carried both a pair of wheat-rye (Triticum aestivum-Secale cereal) 1BL/1RS translocation chromosomes and a pair of Agropyron intermedium (Ai) chromosomes, three carried a pair of Ai chromosomes only, three others carried a pair of 1BL/1RS chromosomes only, and one carried neither 1BL/1BS nor Ai chromosome. Further identification revealed that the identical Ai chromosome in these germplasm lines substituted the chromosome 2D of common wheat (T aestivum L.), designated as 2Ai. The genetic implication and further utilization of 2Ai in wheat improvement were also discussed.

Use of genomic selection and breeding simulation in cross prediction for improvement of yield and quality in wheat (Triticum aestivum L.)

In wheat breeding, it is a difficult task to select the most suitable parents for making crosses aimed at the improvement of both grain yield and grain quality. By quantitative genetics theory,the best cross should have high progeny mean and large genetic variance, and ideally yield and quality should be less negatively or positively correlated. Usefulness is built on population mean and genetic variance, which can be used to select the best crosses or populations to achieve the breeding objective. In this study, we first compared five models(RR-BLUP, Bayes A, Bayes B, Bayes ridge regression, and Bayes LASSO) for genomic selection(GS) with respect to prediction of usefulness of a biparental cross and two criteria for parental selection, using simulation. The two parental selection criteria were usefulness and midparent genomic estimated breeding value(GEBV). Marginal differences were observed among GS models. Parental selection with usefulness resulted in higher genetic gain than midparent GEBV. In a population of 57 wheat fixed lines genotyped with 7588 selected markers, usefulness of each biparental cross was calculated to evaluate the cross performance, a key target of breeding programs aimed at developing pure lines. It was observed that progeny mean was a major determinant of usefulness, but the usefulness ratings of quality traits were more influenced by their genetic variances in the progeny population. Near-zero or positive correlations between yield and major quality traits were found in some crosses, although they were negatively correlated in the population of parents. A selection index incorporating yield, extensibility, and maximum resistance was formed as a new trait and its usefulness for selecting the crosses with the best potential to improve yield and quality simultaneously was calculated. It was shown that applying the selection index improved both yield and quality while retaining more genetic variance in the selected progenies than the individual trait selection. It was concluded that combining genomic selection with simulation allows the prediction of cross performance in simulated progenies and thereby identifies candidate parents before crosses are made in the field for pure-line breeding programs.

Dynamics of Microbial Biomass in a Rainfed Soil Under Wheat Cultivation

A pot experiment was conducted to determine the dynamics of soil microbial biomass in a rainfed soil under wheat cultivation at the University of Arid Agriculture, Rawalpindi, Pakistan. The treatments applied were: 1) a control (CK), 2) NPK (0.44-0.26-0.18 g pot-1), 3) farmyard manure (FYM, 110 g pot-1), 4)poultry manure (PM, 110 g pot-1), 5) FYM (110 g pot-1) + NPK (0.44-0.26-0.18 g pot-1), 6) poultry manure (PM, 110 g pot-1) + NPK (0.44-0.26-0.18 g pot-1), 7) FYM (110 g pot-1) + NPK(S) (0.44-0.26-0.18 g pot-1, one half of the NPK at sowing and the other half one month after sowing), and 8) PM (110 g pot-1) + NPK(S) (0.44-0.26-0.18 g pot-1, one half of the NPK applied at sowing and the other half one month after sowing). The experiment was laid out using a completely randomized design with three replications. Microbial biomass C, N and P contents increased continuously from the beginning of the experiment up to the three-leaf stage. A slight decline was observed at the tillering stage in all treatments except with the organic manures + NPK(S) treatments. After tillering there was an increase in all treatments to the recorded maximum point at the full heading stage in all treatments except with the organic manures + NPK(S) treatments. In the FYM + NPK(S) and PM + NPK(S) treatments; however, there was a continuous increase in microbial biomass up to the heading stage. At the harvesting stage a sharp decline was noted in all treatments. The C:N ratio of microbial biomass in tested soil ranged from 7.8 to 11.3, while C:P ratio of microbial biomass in the tested soil ranged from 22.6 to 35.1 throughout all growth stages of the wheat crop.

Mechanisms of Difference in Mn Efficiency Between Wheat and Oilseed Rape

By solution culture experiment, three wheat genotypes (Ttiticum aestivum L.) and two oilseed rape genotypes (Brassica napus L.) differing in Mn efficiency under Mn-deficient conditions were used to study mechanisms of the difference in Mn efficiency between wheat and oilseed rape. The results showed that there were significant differences in the abilities of MnIV reduction and acidification in root rhizosphere between the two species. Compared with wheat, oilseed rape had much higher reducing capacity and intensity of rhizosphere acidification under Mn-deficient conditions. Moreover, the higher ratio of functional leaves Mn/old leaves Mn in oilseed rape than in wheat was also an important factor for the different Mn efficiencies between the two species.

Selected Mineral Contents in Wheat from Paraguay by X-ray Fluorescence

The two fold purpose of this paper is to determine the composition of selected elements in Paraguayan wheat and flour as well as to analyse the implications of the bromine/bromate content on bakery products： the use （malpractice） of KBrO3 as an additive in the bakery dough to improve the whiteness and other characteristics of bread is well known. Accordingly, selected minor and trace elements in eight varieties of wheat from the center and south areas of Eastern Paraguay as well as commercial flour samples and bakery products were analyzed by XRF （X-ray fluorescence） techniques. The examined elements were K, Ca, Ti, Mn, Fe, Cu, Zn, Br, Rb, Sr. The results on wheat and commercial flour were consistent with those found elsewhere. With regard to the bakery products, in about 35% of the samples, the bromine/bromate content exceeded the normal Br values of Paraguayan flour showing bromate malpractice. From dietary point of view, it should be emphasized that KBrO3 is a complete carcinogen and its use as food additive has been banned. The employment of XRF to analyze bromine is easy, simple and reliable.

The Study of the Anatomical Features of Wheat Grains in the Species T. dicoccum Schuebl,, Sort Mironovskaya-808 and AIIoplasmatic Lines （Their Interspecific Hybrids F9）

In cross sections by microscopic studies have examined the features of the shell thickness grains, cells, aleuronic layer and endosperm in the species T. dicoccum Schuebl., sorts Mironovskaya-808 and their interspecific hybrids F9 （alloplasmatic lines）. The result of studies showed the specific and varietal differences, and differences in hybrid plants on linear parameters size grains, the degree of specificity of the shells grains of wheat and identified species and varietal differences as well as differences among hybrids in the linear dimensions of the cells of the aleuronic layer. It is shown that among the studied forms of wheat allocated species T. dicoccum Shuebl. and the lines D-N-05, D-F-05 and D-40-05-KhNA with relatively large grains, a well-developed endosperm, most of thin shells and large grain aleurone layer cells. They are of most interest for further breeding research in terms of nutritional value.

Influence of Cropping Systems on Soil Properties in Semi-arid Conditions of Setif, Algeria

The effects of two culture systems, conventional and no-till combined the previous crop （lentil and wheat） on soil properties were studied in the experimental site of the station Technical Institute for Field Crops （ITGC） Setif （Algeria） during the crop year 2011/2012. The results indicate that the no-till system affects positively the variables of soil properties and the organic matter has a rate of 2.89% compared to 2.44% in conventional tillage. If the conventional system has an infiltration of moisture relatively higher than that observed for no-till throughout the cycle, the no-tillage is distinguished by a higher storage of moisture at the end of cycle wheat cultivation. The results also indicate that the density （1.44 g/cm）, permeability （22.79 cm/h） and soil compaction （12.51 kg/cm） in no-till were significantly higher compared to conventional tillage 1.35 g/cm, 14.13 cm/h, 7.40 kg/cm, respectively.

Agronomic Behavior of a New Cereal （Primary 6x Tritipyrum： AABBEbEb） in Comparison with Modern Triticale and Iranian Bread Wheat Cultivars

The novel salt-tolerant cereal, primary Tritipyrnm, is the third artificially synthesized crop plant. The agronomic traits and grain yields of 13 primary 6x Tritipyrum lines were evaluated and compared with five modern 6x triticale lines and nine bread wheat cultivars at Bahonar University, Kerman, Iran in a completely randomized block design with three replications. The primary Tritipyrum lines increased the grain yield per plant by 2.8% and 14.1% compared to triticale promising lines and Iranian bread wheat cultivars, respectively. Although the primary Tritipyrum lines were late maturing, they were shorter than the triticale lines and wheat cultivars and superior in many characters such as penultimate leaf area, flag leaf length, penultimate leaf length and time to milky ripeness. Genotypes were divided into four groups for agronomic and morphological traits and four groups for grain yield by cluster analyses. All clusters showed significant differences （a = 5%） for all traits and the first cluster, which comprised primary Tritipyrum lines, had a higher mean grain yield than the other clusters. The results of this first large-scale trial indicated the high adaptation of primary Tritipyrum lines to conditions in Kerman province in South-east of Iran.

Elemental Content in Wheat Products of Asir Region, Saudi Arabia

Wheat is one of the most grown crops in Saudi Arabia. Accurate knowledge of the various elemental concentrations in wheat and its products （bran and flower） is of great importance from nutrition point of view. Wheat samples were obtained from Asir region, 900 Km southern of Riyadh, and analyzed. Up to 50 elements in wheat products were determined. It was observed that the mineral content of bran was much higher than white flour.

Amylose contents of cereals; influence of household processing on the amylose contents of these foods

Amylose is a food starch found in cereals, legumes and root vegetables. Keeping in view the importance of amylose for various food industries as well as its importance on domestic level, the current study was conducted to analyze the amylose content of common cereals e. g rice （sela, coarse and basmati）, maize yellow, Kisan and Azam varieties and wheat （Tatara, Fakhr-e-sarhad and Bakhtawar-92） varieties as well as quantifying the influence of cooking/boiling procedures on the amylose contents of cereals. The maximum amylose content were observed for wheat variety Tatara （24.28%） followed by Bakhtawar-92 （22.74%） and Fakhr-e-sarhad （19.77%）. Among maize and rice varieties studied, Kisan and course rice were rich in amylose content with values of 27.19 and 30.48% respectively. The chapti of Tatra wheat were scored highest for appearance （7.6）, flavor （7.5）, texture （7.6） and overall acceptability （7.55）. The roti of Kisan and Azam varieties got maximum appearance score of 7.6 as compared to 7.4 for maize yellow variety. Basmati rice was scored highest regarding appearance （8.4）, flavor （8.6）, texture （8.6） and overall acceptability （8.53. The moisture content ranged from 10.61 （Azam） to 8.01% （wheat variety Fakhr-e-sarhad）. Cooking reduced the amylose content of wheat bread from （19.77%-24.28%） to （15.47%-15.94%） with cooking time of 5 min, maize bread from （21.48%-27.19%） to （19.53 %-25.85%） with maximum cooking time of 10 min and boiled rice from （24.90%-30.48%） to （24.18%-30.19%） with cooking time ranging from 12 to 20 min. It can be inferred from these studies that the reduction in amylose content were more in chapti/roti preparation of wheat and maize varieties as compared to boiling of rice varieties and that significant varietals differences exist in amylose content of the uncooked samples.

Eight-Regularity of Types of Crop Capacity Structure of Winter Wheat

The elements of crop capacity structure of 13 summer characteristics in 33 winter wheat varieties, qualitative three-regularity and quantitative eight-regularity are investigated through the application of systematic approach. The principle of triadness applied in a language, in a genetic code and other codes is used, i.e. the logic homology is employed. The purpose are （1） to show the use of a systematic approach to the analysis of elements of crop capacity structure of winter wheat; （2） to analyze efficiency, the years of harvests and winter hardiness; （3） to find the way of selection and varieties assessment in terms of the elements efficiency. The quantitative compatibility as the highest with the sign ＂＋＂ and the lowest with the sign ＂-＂ in terms of elements efficiency gives eight types of crop capacities. The type of crop capacity structure ＂＋＋＋＂ can serve as a full （higher） measure of a variety adaptableness and optimality of technologies. The triad of three characteristics as a type-＂＋＋＋＂ in which the first sign is the quantity of ears （QE）; the second is a quantity of grains （QG）; the third is the weight of grains （WG） creates the highest level of crop capacity.

Release of Stem Rust Resistant Wheat Varieties for Commercial Production in Kenya

Detection in 1999 of a new stem rust （Puccinia graminis f. sp. tritici） race Ug99 in Uganda with broad virulence including the virulence for Sr31 and its migration to Kenya and Ethiopia has been recognized as a significant threat to local and world wheat production. All the Current Kenyan commercial varieties are susceptible to this race. This study was aimed at identifying suitable wheat varieties with resistance to Ug99 and replacing the susceptible commercial varieties through multi-locational testing and variety release. Thirty three lines were identified from a prescreen population of 104 lines and tested in 3 wheat growing regions in Kenya for two seasons in 2006 and 2007. The resulting four superior lines were evaluated under the National Performance Trial （NPT） where two lines which out-performed the best check variety were released as for commercial production. ＇Robin＇ was the best line and out yielded the commercial variety by 27%. ＂Eaglel0＂ was the second best and was better significantly than the check variety. These two lines which combined both adult plant resistant gene Sr2 complex and other major genes are expected to have some durable resistance and may be used to replace the current susceptible commercial varieties grown in Kenya.

Magnesium Uptake and Palygorskite Transformation Abilities of Wheat and Oat

Weathering of clay minerals is a source of nutrients to plants. Palygorskite is a Mg-rich fibrous clay mineral that commonly occurs in the soils and sediments of arid regions. Although many studies have examined the environmental conditions required for the formation and stability of palygorskite, information on the transformation of this mineral in the root zone （or rhizosphere） of agricultural crops is limited. This study explored the possibility of palygorskite transformation in the rhizosphere of wheat and oat and compared the ability of these crops to extract structural Mg from palygorskite. The crops were cultivated in pots consisting of a mixture of sand from Hamadan region, Iran and Florida palygorskite, irrigated with distilled water, and treated with either complete or Mg-free nutrient solutions. After 100 d, Mg uptake by the crops was measured. Clay-sized particles in each pot were also separated from the sand and were analyzed through X-ray diffraction （XRD）. The X-ray pattern of the particles was compared with that of the pure palygorskite particles （before cultivation）. The results showed that palygorskite could provide sufficient Mg for the growth of wheat in the pots supplied with Mg-free nutrient solution. In spite of the magnesium uptake by both plants from the palygorskite structure, no detectable peaks indicating the transformation of pMygorskite were recognized by XRD. A decrease of 1.05 nm in peak intensity was more obvious for the pots containing palygorskite and irrigated with Mg-free nutrient solution than for the pots irrigated with complete nutrient solution. Although the decrease in peak intensity was greater for oat than wheat, indicating greater palygorskite weathering by oat, Mg uptake by oat was low, as evidenced by the deficiency symptoms observed.