Grain and flour quality of wheat genotypes grown under heat stress

Heat stress during the grain-filling period is the main abiotic stress factor limiting grain yield and quality in wheat (Triticum aestivum L.). In this study, 64 wheat genotypes were exposed to heat stress during reproduction caused by delayed sowing in two growing seasons. Grain yield, 1000 grain weight (GW), grain hardness (GH), and grain-quality related traits were investigated. Heat stress caused a significant decrease in GW through reducing starch content (SC) and a non-compensating rise in protein content (PC), and thereby resulted in lower yield. In addition, significant increases in flour water absorption (WA), Zeleny sedimentation volume (ZT), ash content (AC), lipid content (LC), loaf volume (LV), wet gluten content (WG), dry gluten content (DG), gluten index (GI), and amylopectin content (APC) were found following heat stress. In contrast, decreases in grain moisture content (MC) and amylose content (AMC) induced by heat stress were observed. The heat-tolerant genotypes were superior in grain yield, GW, SC, AMC, and MC. While the sensitive genotypes contained higher PC, LV, GI and AMP. A group of wheat genotypes characterized with a higher yield, AMC, GW, and SC as well as lower PC, WA, GH, ZT, and LV; and was found to be the most heat tolerant by principal component analysis. Lighter weight and smaller grains produce a smaller starchy endosperm with lower quality (less amylose) and higher grain protein content in heat stress compared to normal conditions. Heat stress caused by delayed sowing improves some of the baking-quality related traits.     

灌溉频次和时期对冬小麦籽粒产量及品质特性的影响

为探讨我国北方地区冬小麦的节水灌溉模式,2006—2008年,在中国科学院栾城农业生态系统试验站,以冬小麦品种科农9204为试验材料,在总灌溉量为120mm的条件下,研究了灌溉次数和灌溉时期对籽粒产量、水分利用效率(WUE)、籽粒蛋白质含量以及相关主要品质特性的影响。结果表明,拔节期、抽穗期和灌浆期一次灌溉分别有利于产量、干物质积累量和千粒重的形成或提高;两次灌溉处理中,以拔节和抽穗期各灌60mm处理籽粒产量最高,籽粒蛋白质产量有随灌溉时期后移而降低的趋势;冬小麦生育期间随灌溉次数增多和灌溉时期后移,湿面筋含量、面团形成时间、面团稳定时间等均显著降低。综合考虑冬小麦的籽粒产量、WUE、营养品质和加工品质,在总灌溉量为120mm的条件下,以拔节和抽穗期各灌溉60mm为宜。     

Effect of water stress on the boron response of wheat genotypes under low boron field conditions

Sterility has emerged as a widespread problem for wheat (Triticum aestivum) production in South and South-east Asia. Whilst boron (B) deficiency is commonly associated with sterility in wheat, the expression of sterility is complicated in rainfed conditions by a number of environmental factors including water stress. A field experiment was conducted to examine the effect of water stress on B response of wheat genotypes on a low B soil (0.087 mg B kg-1soil) at Chiang Mai, Thailand (18°45 N, 99° E) during the dry season from November to March. The experiment consisted of three factors arranged in a split-split plot design with two levels of irrigation: water stress (I–) and full irrigation (I+) in main plots, two levels of B: 0 kg (B0) and 1 kg B ha-1 (B+) as borax in sub plots and four wheat genotypes: SW 41, BL 1022, UP 262 and Sonora 64 in sub–sub plots. Water stress was applied by discontinuing irrigation in I– treatments after the double ridge stage. In all genotypes, above ground biomass was decreased by I–, but not by B deficiency. Significant B×genotype interactions were detected for reproductive growth. SW 41 and BL 1022 strongly responded to added B with relief from B deficiency symptoms at anthesis and improved grain set index (GSI), grains ear-1, ears with grain and grain yield at maturity. By contrast, Sonora 64 could set grain well at B0 and did not show any response to added B with respect to these parameters. Grains ear-1 of SW 41 and BL 1022 was not affected by full irrigation at B0, but were significantly increased when fully irrigated with added B. In all genotypes, B concentration of the flag leaf and the ear at booting and at anthesis was significantly higher in B+, but was not affected by irrigation. Boron × irrigation interactions detected in this study indicate the possibility of the influence of water stress on the severity of wheat sterility in South and South-east Asia.     

Abscisic acid in developing grains of wheat and barley genotypes differing in grain weight

Two genetically related wheat lines growing in cabinets were given different temperatures during grain filling, and abscisic acid (ABA) was measured in whole grains by gas chromatography with an electron-capture detector. Three genetically related barley lines grown in the field were assayed for ABA content in endosperm and embryo fractions separately by radiommunoassay.Maximum grain growth rate and final weight per grain of the two wheat lines differed by 50–60% at low temperature and 30–40% at high temperature. During grain development two peaks in ABA level were observed at low temperature but only one at high temperature. At times when differences in grain growth rate between genotypes and between temperature treatments were large, the corresponding differences in ABA concentration were small. In barley, one line (Iabo 14) had 30% heavier grains than the other two (Onice and Opale). Endosperm ABA concentrations showed no clear differences between genotypes until grain filling was nearly complete. Embryo ABA levels were up to 10-times greater than those in the endosperm, with Opale having significantly less ABA in the embryo than the other two cultivars.Our experiments did not provide evidence for a causal relationship between ABA levels during grain filling and grain growth rate or final weight.Abbreviations ABA Abscisic acid - DAA days after anthesis - DW dry weight - FW fresh weight     

不同气象条件下小麦冷源的品质变异

小麦冷源是一种冷温供体材料,有较强的降温作用,当受体小麦接受冷温供体的配子后,其后代冠温呈普遍下降态势,且部分受体小麦的温度型可由非冷型转化为后代的冷型,而冷型小麦具有代谢功能好且利于高产、稳产的特征,故小麦冷源不但对冷型小麦的问世有重要诱导作用,且能更好促进小麦的高产、稳产.将小麦冷源材料放置在不同的气象条件之下,以研究其籽粒品质的变异状况.结果表明,小麦冷源和非冷源相比,17项籽粒品质性状变异等级的加权平均值为1.9877,后者为2 8171,显示出小麦冷源的籽粒品质具有明显变异小、较稳定的特征,这和籽粒形成过程中蛋白质、淀粉及其组分的含量,相互间的比例变异小密切相关.由于小麦冷源具有籽粒品质变异小的特性,因而,这种特性就利于在其后代冷型小麦上显现,从而使冷型小麦的一些优良品质性状能在生产上反复重演,这不但进一步赋予了利于高产、稳产的冷型小麦以优质、稳质的性状,并能最终促进小麦生产的较大发展,其意义是十分重要的.     

Genetic variation of salt-stressed durum wheat (Triticum turgidum subsp. durum Desf.) genotypes under field conditions and gynogenetic capacity

Agriculture has new challenges against the climate change: the preservation of genetic resources and the rapid creation of new varieties better adapted to abiotic stress, specially salinity. In this context, the agronomic performance of 25 durum wheat (Triticum turgidum subsp. durum Desf.) genotypes (nineteen landraces and six improved varieties), cultivated in two semi-arid regions in the center area of Tunisia, were assessed. These sites (Echbika, 2.2?g?l^?1; Barrouta, 4.2?g?l^?1) differ by their degree of salinity of the water irrigation. The results showed that most of the agronomic traits (e.g. spike per meter square, thousand kernels weight and grain yield) were reduced by salinity. Durum wheat landraces, Mahmoudi and Hmira, and improved varieties, Maali and Om Rabia showed the widest adaptability to different quality of irrigation water. Genotypes including Jneh Kotifa and Arbi were estimated as stable genotypes under adverse conditions. Thereafter, salt-tolerant (Hmira and Jneh Khotifa) and the most cultivated high-yielding (Karim, Razzak and Khiar) genotypes were tested for their gynogenetic ability to obtain haploids and doubled haploid lines. Genotypes with good induction capacity had not necessarily a good capacity of regeneration of haploid plantlets. In our conditions, Hmira and Khiar exhibited the best gynogenetic ability (3.1% and 2.9% of haploid plantlets, respectively).     

黄土高原地区春小麦对有限灌溉的反应及其生理生态基础

从对黄土高原地区有限灌溉条件下作物生理生态反应的众多研究中得出：（1）水分轻度亏缺时,作物可通过根信号物质ABA调节叶片的气孔导度。非水力根信号作用太强,可因降低光合作用而减少干物质生产和影响干物质分配模式而影响产量和水分利用效率,故削弱非水力根信号的作用将有利于提高产量。（2）浅层根系占根系总量比值越高,对干旱越敏感,表现为根信号能力增强;深层根系所占比例越高,越有利于土壤深层水分利用,并可削弱根信号,同理,给土壤中下层补水或采用播种前灌溉,可因为减少了无效蒸发,且削弱根信号而提高水分利用率。（3）本地区有限灌溉的最佳时期由于降水变率较高而变得较为复杂,不同降水年型,最佳灌溉时期差异很大,对有限灌溉进行科学管理还需要做更多的研究工作。     

限水灌溉冬小麦冠层氮分布与转运特征及其对供氮的响应

以高产冬小麦品种周麦18为材料,在大田春灌1水条件下,设置不同供氮水平和氮肥运筹处理试验,研究并探讨了在华北地区限水灌溉条件下氮肥施用对冬小麦冠层叶片氮素时空分布与转运及氮肥利用的影响。结果表明,冬小麦适量施氮可显著增产,2008-2009年以施氮量180 kg/hm²时(N21)产量最高,为8749 kg/hm²;2009-2010年以施氮量270 kg/hm²时(N32)产量最高,但施氮量210 kg/hm²(N22)处理与N32处理产量无显著差异,分别为8340 kg/hm²和8558 kg/hm²。氮肥利用效率和氮肥偏生产力均随施氮量增加而降低;氮肥利用率与氮肥农学效率均随施氮量的增加呈先升后降的趋势,分别在N21和N22处理时最高。冠层叶片氮素含量和积累量随叶层层次自上而下降低而下降,垂直梯度分明,各时期冠层叶片氮素垂直梯度随施氮量的增加总体呈先增大后减小的趋势。冠层叶片氮素转运量、转运率和对籽粒的贡献率均呈现为:第1层>第2层>第3层>第4层。相关分析表明,冠层叶片氮素梯度与叶片氮素转运率呈显著正相关关系(R²=0.722^*),与贡献率呈极显著正相关关系(R²=0.975^**)。适量施氮(120-210 kg/hm²)增大了叶层间氮素垂直分布梯度,促进了氮素在植株内的运移分配,有利于叶片氮素向外转运,提高了叶片氮素转运量和对籽粒贡献率,保持了较高的氮素利用率。施氮过多(330 kg/hm²)减小了叶层间氮素垂直分布梯度,减弱了氮素在植株内的再利用,叶片氮素转运不畅,导致叶片氮素转运量和对籽粒贡献率下降,氮素利用率显著降低。连续两年试验结果显示,通过适量氮肥调控可以增大冠层叶片氮素垂直梯度,有利于叶片中的氮素输出,促进氮素的再分配、再利用,从而提高氮素利用率,并可获得较高的籽粒产量和蛋白质含量。     

The effects of elevated temperature and atmospheric carbon dioxide concentration on the quality of grain lipids in wheat (Triticum aestivum L.) grown at two levels of nitrogen application

Wheat plants were cultivated under growth regimes combining two temperatures (ambient and 4°C above ambient temperature) with two concentrations or carbon dioxide (350 and 700 μmol mol) and two nitrogen fertilizer applications (high and low). The aim of this study was to define any changes in the acyl lipid composition of wheat grains which could result from alterations in the growth conditions. Qualitative and quantitative changes were observed in both non-starch and starch lipid fractions. Temperature was by far the most influential growth factor, although interactions between all three growth conditions occurred, as confirmed by analysis of variance. Growth at elevated temperatures had the general effect of reducing the amounts of accumulated lipids, particularly non-polar lipids (1322 nig fatty acids per 100 g fresh weight at ambient temperatures as opposed to 777 mg fatty acids per lOOg fresh weight at 4°C above ambient temperatures). There were changes in the proportions of the major non-starch as well as the starch lipids. In the former category, non-polar lipids (principally triacylglyc-erols), the membrane glycosylglyccridcs and phos-phatidylcholinc were the main constituents, whereas in the starch lipids, lysophosphatidylcholine and lysophos-phatidylethanolamine represented over 70% of the total. Depending on the growth conditions, the percentages of lipids such as monogalactosyldiacylglycerol, digalactosyl-diacylglycerol and phosphatidyleholine (non-starch) or the starch lysophosphatidylethanolamine varied 2-fold or more. Significant changes in the acyl composition of individual lipids were also observed, most often in the proportions of palmitate, oleate and linoleate. The observed alterations in wheat lipids arc likely to affect the properties of any flours derived from grain grown under climate change conditions.     

咸水灌溉对冬小麦籽粒品质特性和产量的影响

为缓解农业用水供需矛盾,解决井灌区地下水超采问题,探究华北平原广泛分布的地下咸水灌溉对冬小麦品质和产量的影响,实现农业可持续发展,本研究在始于2006年的长期定位试验基础上,设置1、2、4、6、8 g·L^-1共5个灌溉水矿化度处理,其中1 g·L^-1灌溉水(取自当地地下水)为对照,研究咸水灌溉对冬小麦籽粒品质特性和产量性状的影响。结果表明: 与对照相比,当灌溉水矿化度≥4 g·L^-1时可显著增加籽粒吸水量、面团形成时间、沉淀值、湿面筋和粗蛋白含量,但显著降低出粉率、面团稳定时间和面筋指数;长期灌溉高矿化度咸水(4～8 g·L^-1)显著降低了冬小麦穗数(44.0%～60.7%)和籽粒产量(35.6%～64.7%)。在连续多年咸水灌溉条件下,与对照相比,2 g·L^-1灌水处理对籽粒产量及产量构成因素无显著影响,且能提高吸水量、面团形成时间、沉淀值、湿面筋和粗蛋白含量等籽粒品质。采用主成分分析法对冬小麦产量性状和品质特性进行综合性评价,得出2 g·L^-1灌水处理综合效果最优。本研究可为华北平原咸水资源高效利用提供理论支撑。     

Photosynthetic characteristics of peanut genotypes under excess and deficit irrigation during summer

Physiology and Molecular Biology of Plants - In a field experiment three irrigation treatments were given to twelve peanut genotypes through drip. At 80 days after sowing (DAS) the amount...     

春小麦对不同灌水处理的气孔反应及其影响因子

选用3个春小麦品种（系）,采用大田试验方法,在冬灌1800 m³·hm^-2的基础上,在生育期设3次灌水处理（T₁）、2次灌水处理（T₂）和1次灌水处理（T₃）,每次灌水1050 m³·hm^-2,研究土壤水分对春小麦生育期气孔导度的影响及气孔导度与相关环境因素的关系.结果表明：灌水处理对春小麦生育期气孔导度的影响较大,气孔导度随着灌溉次数的减少逐渐降低,同时不同基因型间存在差异.从拔节期到开花期,不同处理春小麦气孔导度变化一致,都呈先升高后降低趋势, 在抽穗期达到峰值;开花期之后各处理出现差异,T₁各品种气孔导度先下降后上升,T₂品种间表现不同,T₃一直呈下降趋势.各环境因子中,大气相对湿度对春小麦气孔导度的影响最大,两者的相关系数在T₂和T₃中分别达显著(0.82^*)和极显著水平(0.92^**).春小麦适应水分亏缺的气孔调节机理为反馈式调节.     

不同pH模拟酸雨对冬小麦籽粒营养品质的影响

在大田试验条件下研究了不同pH模拟酸雨对冬小麦籽粒氨基酸、蛋白质、可溶性糖、还原糖、淀粉以及总酸度的胁迫效应,以期为防治我国农作物的酸雨灾害提供基础理论依据。结果表明,pH≤4.5酸雨处理会抑制总游离氨基酸的合成,且酸度越强,抑制越明显。蛋白质(可溶性蛋白质、总蛋白)含量随着酸雨酸度的增强逐步下降,且在极酸性条件下降低较明显。pH≤4.5酸雨处理对可溶性糖的合成会有较强的抑制作用。pH≤2.5时还原糖的合成明显受抑。随着酸雨酸度的增强,总酸度和酸糖比均表现出先增加后下降的变化趋势,且在pH=3.5处达到最大值。pH≤3.5酸雨处理显著抑制淀粉的合成,且对支链淀粉的影响较明显,致使淀粉支/直比下降。     

Effects of water supply on root traits and biological yield of Durum (Triticum durum Desf.) and Khorasan (Triticum turanicum Jakubz) wheat

The ability of a plant to change its root characteristics to increase the acquisition of soil water is an important adaptation mechanism to water limitation. In this regard, a field study was carried out in the Pannonian region of eastern Austria with two tetraploid wheat genotypes, i.e. Durum (Triticum durum Desf.) and Khorasan (Triticum turanicum Jakubz), during a comparatively wetter and drier year, i.e. 2008 and 2009, respectively. The genotypes showed significant differences in average root diameter and fine root length. All root traits varied with soil depth. The highest root length density and root biomass were observed with Khorasan wheat in 0–10 cm soil depth. Durum wheat showed a stronger response in fine roots to water availability and produced more fine roots in the moist year. Electric root capacitance was higher with Khorasan wheat. Durum showed higher biological yield stability across years with different precipitation with respect to above- and belowground biomass. It produced more leaf area under humid conditions. Khorasan allocated more assimilates to belowground organs in dry conditions, but without positive effect on aboveground biomass.     

新疆冬小麦籽粒灌浆和品质性状对滴灌用水量的响应

为给滴灌冬小麦节水高产优质栽培提供科学依据,于2012—2013和2013—2014年连续两个冬小麦生长季,以‘新冬22号’为试验材料,在大田滴灌条件下,设置了灌水量为3150、3900、4650、5400和0 m³·hm^-2共5个处理(分别用W₁、W₂、W₃、W₄和CK表示),研究了不同滴灌量对冬小麦籽粒灌浆及品质性状的影响.结果表明: 不同处理滴灌冬小麦籽粒灌浆特性呈“S”型变化曲线,均符合Logistic生长函数模型,且拟合度较高;籽粒灌浆快增期出现在花后12~20 d,最大灌浆速率(V_m)随滴灌量的增加呈“先增后降”的变化趋势,且两年均以W₃处理最大,分别为2.16和2.59 g·d^-1.随着滴灌量的增加,籽粒容重、蛋白质含量、出粉率、湿面筋含量、面团稳定时间、弱化度及面团拉伸阻力和拉伸比均呈“先增后降”的变化趋势,均在W₃处理下达到最高;而面团吸水率和延伸度则呈“先降后增”的变化趋势,在W₃处理最低;沉降值逐渐增大,面团形成时间逐渐变短;籽粒产量均以W₃处理最高,为8913(2013年)和8602 kg·hm^-2(2014年),分别较同年W₁、W₂、W₄、CK高25.0%、14.8%、4.4%、35.6%和12.4%、2.8%、1.1%、33.0%.综上,在本试验条件下冬小麦滴灌量在4650 m³·hm^-2时可达到高产和优质的统一.     

不同试点灌溉方式对冬小麦产量和品质性状的影响

小麦是我国主要的粮食作物之一。随着人们生活水平的提高,对小麦高品质的需求日益迫切。未来全球环境变化背景下,CO2 浓度升高、气候变暖、降水格局变化等将可能影响作物的生理过程,继而影响作物产量和质量。为此,选择两个试点(CO2 浓度、温度等环境条件不同) ,同期进行不同灌溉方式对两个冬小麦品种(中育5号和中优970 1)的产量和品质影响的试验研究。结果表明:2灌(拔节水和开花水)对小麦经济产量最有利;小麦生育后期增加灌溉可提高千粒重,尤其浇灌浆水对增加千粒重有利。在小麦拔节后期,随灌溉增加,小麦品质性状普遍呈现下降趋势,但个别品质性状因品种而异,即灌溉增加,对中优970 1的面包体积影响不大,对其沉降值、面团拉伸参数反而有利。同一品种产量和品质性状有明显的地域差异,在小麦开花至成熟期,大田环境CO2 浓度较高(增幅6 9.0μmol/ mol)、日均温度高2℃多的北京试点,与安阳试点相比,产量表现较低,多数小麦品质性状较优。说明北京试点的环境条件有益于品质改善,不利于产量提高,而且在小麦生育后期较高温度可能更为影响小麦产量和品质。从而在未来全球气候变暖背景下,温度小幅增加将可能改善小麦品质,但产量减少     

水氮互作对固定道垄作栽培春小麦根系生长及产量的影响

为探讨固定道小麦栽培方式下适宜的水氮组合,以低水1200 (W₁)、中水2400 (W₂)、高水3600 m³·hm^-2 (W₃)为主处理,0 (N₀)、低氮90(N₁)、中氮180 (N₂)、高氮270 kg·hm^-2 (N₃)为副处理,采用裂区设计,对固定道垄作栽培方式下水氮互作对春小麦根系生长及产量的影响进行了研究.结果表明:水氮互作能显著影响春小麦根干质量密度(RWD),RWD随着小麦生育期的进程表现为先增大后减小的趋势,在灌浆期达最大;RWD对施氮量的响应取决于灌溉量,在W₁下,RWD在N₁处理下最大,在W₂下,RWD随着施氮量的增加在N₂处理下最大,在W₃下,RWD随着施氮量的增加在N₃ 处理下最大;不同灌溉处理下RWD表现为W₂>W₃>W₁;施氮与灌水显著影响RWD,表现为灌水>氮肥>水氮互作,在W₂N₂处理下最大.根冠比随着灌水量与施氮量的增加逐渐减小,在W₁N₀处理下根冠比最大;85%以上的小麦根系分布于0～40 cm土层,产量与0～40 cm土层RWD呈显著抛物线回归关系,与40～60 cm土层RWD呈显著线性正回归关系.W₂灌溉条件可以促进小麦根系向中下层(40～60 cm)分布;灌水施氮能显著影响春小麦籽粒产量与生物产量,生物产量随着施氮量和灌水量的增加而增加,籽粒产量在W₂N₂最大;灌水生产力随灌水量的增加逐渐降低,氮肥农学利用率随施氮量的增加而减小.因此,在固定道垄作栽培方式下,施肥量与灌水量控制在N₂ (180 kg·hm^-2)与W₂(2400 m³·hm^-2)条件下有利于促进根系生长,进而提高春小麦籽粒产量及水氮利用效率,是河西灌区固定道小麦栽培方式下适宜的水氮组合.     

灌水对不同品种小麦茎和叶鞘糖含量及产量的影响

以冬小麦品种济麦20和泰山22为材料,设置全生育期不灌水(W0)、灌冬水+拔节水(W1)、灌冬水+拔节水+开花水(W2)、灌冬水+拔节水+开花水+灌浆水(W3)4个处理,研究不同灌水处理对小麦倒二茎节间和叶鞘中水溶性碳水化合物含量和籽粒产量的影响.结果表明:两品种W0处理灌浆初期倒二茎节间和叶鞘的可溶性总糖、聚合度(DP) ≥4和DP=3的果聚糖含量最高,灌浆后期的果糖含量最高,这有利于倒二茎节间和叶鞘水溶性碳水化合物的积累与降解,从而提高千粒重,灌水处理间比较,济麦20的W1处理在灌浆初期倒二茎节间和叶鞘的DP≥4、DP=3果聚糖含量和灌浆中后期的可溶性总糖、果糖含量最高,其籽粒产量也最高;泰山22的W2处理在灌浆初期倒二茎节间和叶鞘的DP≥4、DP=3果聚糖含量最高,灌浆后期的果糖含量高于W1处理,其籽粒产量也最高,品种间比较,泰山22灌浆阶段的倒二茎节间和叶鞘的可溶性总糖、DP≥4果聚糖含量和灌浆后期的果糖含量高于济麦20.两品种的籽粒产量对水分处理的响应不同,济麦20的籽粒产量在W0和W1条件下高于泰山22,在W2和W3条件下低于泰山22.本试验中,济麦20的W1处理和泰山22的W2处理有利于倒二茎节间和叶鞘中水溶性碳水化合物的积累与降解,其籽粒产量显著高于其他处理,分别是两品种的最优水分处理.     

Carbon isotope discrimination and mineral composition of three organs in durum wheat genotypes grown under Mediterranean conditions

Carbon isotope discrimination (delta) has been proposed as a good criterion for transpiration efficiency and grain yield improvement. Its measurement, however, remains very expensive. Ash content (ma) has been proposed as an alternative criterion for delta in bread wheat and barley. The aims of this study were (i) to analyse the relationships between delta and mineral composition in different durum wheat plant parts and (ii) to compare the variation of these traits between landraces and improved varieties from different geographic origins. For this purpose, delta, ma, and composition in four minerals (K, Mg, P and Si) were assessed in flag leaves and awns at anthesis, and in mature grains of ten durum wheat genotypes grown under rainfed Mediterranean conditions. The three plant parts differed significantly for the measured traits. Significant correlations were noted between delta and ma in the flag leaf and in the grain. Silicon content in flag leaves and potassium content in awns were also positively related to delta of the considered plant part. The coefficient of correlation between delta and ma was generally higher than that observed between individual mineral content and delta, suggesting that ma is the better alternative criterion for delta. In addition, grain yield was related to grain delta and both ma and potassium content in awns. Harvest index was correlated with delta and ma of grain and flag leaf. These results emphasised that ma values in flag leaf and grain represent the efficiency of carbon partitioning to the grain. Improved varieties showed higher delta and ma values than landraces. Differences between Middle-East and West Mediterranean genotypes for the measured traits were also presented and discussed.