Evaluation of Rice Genotypes under Propionate Stress

Abstract

The objective of the present work was to evaluate the response of 25 rice genotypes to propionate, a compound largely produced in low‐drainage and high‐organic matter‐content soils. The work was performed in hydroponics with four doses and a random block design with three replications. The variables measured were root (RL) and shoot (SL) length, number of roots (NR), and root (RDM) and shoot (SDM) dry matter. Analyses of variance, relative performance, and regression fitting were performed, showing significance for most variables. The variable RL was the most affected by propionate, and the use of this variable for screening genotypes indicated 6 tolerant and 19 sensitive genotypes. Most tolerant genotypes belonged to irrigated japonica.     

Influence of year and planting date on fatty acid chemistry of high oleic acid and normal peanut genotypes

The effect of an early-, mid-, or late-season planting date on the fatty acid chemistry of four high oleic acid, one mid oleic acid, and five normal oleic acid peanut (Arachis hypogaea L.) genotypes was evaluated over a three year period. Oleic acid was also compared to other fatty acids and to indices of oil quality. High-oleic genotypes included SunOleic 97R, UF98326, UF99621, and 88x1B-OLBC1-6-1-3-1-b2-B with a mean oleic acid content between 77.8 and 82.5%. Florida MDR98, a mid-oleic cultivar, was intermediate in oleic acid chemistry (59.8-68.0%). The normal oil chemistry lines (Georgia Greene, Andru93, Florunner, 86x13A-4-2-3-2-b3-B, and UF97102) had an oleic acid content between 50.0 and 59.0%. The ratio of oleic to linoleic (O/L) was 18:1 to 51:1 for high-oleic lines and 1.7:1 to 3.5:1 for normal genotypes. When analyzed as a split-split plot in time, year had a highly significant effect (P < 0.001) on the eight main fatty acids, iodine value, ratio of unsaturated to saturated fatty acids (U/S), and percentage of saturated fatty acids. Thus, data were analyzed separately by year. Although genotypic effects were highly significant each year, planting date influenced oil chemistry in two of three years. During both 1999 and 2000, 11 of 12 variables were influenced by planting date and by genotype x planting date interactions. Iodine values were approximately 75 for high-oleic lines compared to 90-95 for normal genotypes. The highest correlations occurred for oleic acid (18:1) and linoleic acid (18:2) (r = -0.996) and for oleic and palmitic (16:0) acids (r = -0.959). Oleic acid was also inversely related to iodine value (r = -0.978) and to percentage saturation (r = -0.841).     

Rice Genotype Responses to Acetate to Improve No‐Tillage and Minimal‐Tillage Systems

The goal of this work was to evaluate the response of 25 rice genotypes to the toxic effect of acetate, which is commonly produced in low‐drainage and organic‐matter‐rich soils. The work was performed in hydroponics with four acetate doses. The experimental design was random blocks with three replications on a factorial scheme. The variables root (RL) and shoot (SL) length, number of roots (NR), and root (RDM) and shoot (SDM) dry matter were measured. Analyses of variance, relative performance, and regression adjustments were used. Only the dose × genotype interaction effect for SL, NR, and SDM were not significant. Among the variables analyzed, RL was influenced the most by the acetate treatments. The regressions established for this variable revealed 6 tolerant and 19 sensitive genotypes. Most of the tolerant genotypes were irrigated japonica.     

Nagina 22 mutants tolerant or sensitive to low P in field show contrasting response to double P in hydroponics and pots

ABSTRACT

A simple screening method is needed to identify rice genotypes tolerant to low phosphorus (P) in soil. Nagina 22 (N22) mutants were classified as gain of function (gof) and loss of function (lof) for tolerance to very low P (soil Olsen P 2.01 mg kg^?1). Two gof and two lof mutants were grown in hydroponics and in pot experiment at three P levels (-P, +P and +2P). Comparing response at +P and +2P in hydroponics we found that shoot and root dry weight were significantly less in gof and significantly more in lof in +2P. In pots with soil, tiller number and yield/plant was 3 fold less in gof but 2.5 to 3 fold more in lof and N22 in +2P compared to +P. That 2P can be used to identify low-P tolerant genotypes was validated using 3 low-P tolerant and 3 sensitive varieties whose response to low P soil is well documented. Both shoot and root dry weight was significantly less in +2P than in +P in tolerant and significantly more in sensitive genotypes. Thus screening in hydroponics in +2P can help identify low-P- tolerant genotypes easily and rapidly avoiding field screening.     

苗期耐低磷烟草基因型筛选及其磷效率

【目的】筛选耐低磷及磷高效作物是充分利用土壤磷素和磷肥,减少磷肥施用对环境污染的重要手段。调查烟草基因型的磷素利用效率可为培育磷高效烟草品种提供理论依据。【方法】以71个烟草品种为供试材料进行了水培试验。以Hoagland营养液为基础(1.0 mmol/L KH₂PO₄),调整营养液磷水平0.01 mmol/L KH₂PO₄ (低磷)。烟苗在完全营养液中生长至4叶1心时进行处理。处理21天后,采样分析烟草主要生长、形态和生理指标,筛选耐低磷基因型判别指标,并对品种进行磷效率类型划分。【结果】全株磷累积量、地上部干重、根干重、株高、总根长及根直径可作为鉴定耐低磷烟草基因型的苗期筛选指标。将全株磷累积量和地上部干重的耐低磷相对值进行聚类热图分析,鉴定出8个耐低磷品种、21个低磷敏感品种及42个中间型品种。同时,依磷效率综合值作散点图发现,耐低磷品种中有4个低磷低效正常磷低效型、2个低磷高效正常磷高效型和2个低磷高效正常磷低效型,低磷敏感品种中有14个低磷低效正常磷低效型、1个低磷高效正常磷高效型和6个低磷低效正常磷高效型。【结论】初步确定K326和云烟105为耐低磷且磷高效品种,G28、闵烟3号、DB101、Oxford 2028、14P10、CV70、云烟98、MSB44、单育2号、净叶黄、CB1、中烟101、RG11和MSB31等14个为不耐低磷且磷低效品种。     

Effect of salt stress on Growth and Ion accumulation of alfalfa (Medicago sativa L.) cultivars

Alfalfa (Medicago sativa L.) yield and nutrient contents may be affected under salinity condition. Thus, this experiment was conducted to determine the effect of three salinity levels (60, 120, and 180 mM NaCl) on shoot and root dry weights, and mineral contents of three alfalfa cultivars. With the increasing salinity levels sodium (Na) and magnesium (Mg) contents increased; but potassium (K), nitrogen (N), phosphorous (P), calcium (Ca), zinc (Zn), and copper (Cu) contents and root and leaf weights decreased; however, changes in these traits depended on cultivar and salinity level. However, Rehnani, a tolerant cultivar, had the lowest Na and Mg contents and the highest K, N, P, Ca, Zn, and Cu contents and dry weights under all of the salinity levels. Moreover, leaf dry weight and leaf P content had the highest correlation with salt tolerance suggesting that these traits may be used as a marker for selecting salts that are tolerant among genotypes in alfalfa.     

A Comparative Analysis of Salinity and Nickel Tolerance of Tomato (Solanum lycopersicum L.)

ABSTRACT

An experiment was conducted in a randomized factorial design with three replicates to elucidate the comparative tolerance of tomato genotypes and hybrids against salinity (NaCl) and nickel (Ni) toxicity. Six tomato genotypes and two hybrids were exposed to different levels of NaCl (0, 75 and 150 mM) and Ni (0, 15 and 20 mg L^?1) in hydroponics for 4 weeks. Increasing levels of NaCl and Ni significantly decreased the growth of all the genotypes. Cluster analysis for relative tolerance of the genotypes and hybrids showed that the genotype “Naqeeb” is the most tolerant whereas the genotype “Nadir” proved to be the most sensitive against both the NaCl and Ni-toxicity. Leaf tissues Na⁺ and Ni concentration significantly increased by increasing NaCl and Ni levels in the growth medium with tolerant genotype “Naqeeb” showing the lowest and sensitive genotype “Nadir” with the highest concentration. Antagonistic relation between uptake of Na⁺ and Ni was observed in all the genotypes and hybrids. Results revealed that tomato genotypes and hybrids shared the same defense mechanism against salinity and Ni-toxicity tolerance. The genotypes tolerant against one stress can be regarded as tolerant against other stress as well.     

Genotypic variation for nitrogen uptake and assimilation using hydroponic culture technique in wheat

Hydroponic culture technique is an alternative way of studying nitrogen metabolism. In this study, the response of six wheat genotypes (PBW 621, PBW 636, GLU 1356, BW 8989, GLU 700, and PBW 343) with respect to nitrogen-metabolizing enzymes in relation to accumulation of soluble proteins and amino acids at two concentrations of nitrogen (2 and 6 mM) was studied. Activities of nitrate reductase (NR) and glutamine synthetase as well as soluble proteins, amino acids, and nitrogen content increased in all six genotypes with increasing concentration of nitrogen in roots as well as shoots. Shoots maintained higher activities of NR and glutamine synthetase; apparently contents of soluble protein, amino acid, and nitrogen were also higher. The upregulation of NR and glutamine synthetase activities with increased concentration of nitrogen possibly contributes to higher nitrogen assimilation efficiency of three genotypes (PBW 621, PBW 636, and GLU 1356) compared to other genotypes.     

Differential Soil Acidity Tolerance of Dry Bean Genotypes

Soil acidity is a major yield-limiting factors for bean production in the tropical regions. Using soil acidity–tolerant genotypes is an important strategy in improving bean yields and reducing cost of production. A greenhouse experiment was conducted with the objective of evaluating 20 dry bean genotypes for their tolerance to soil acidity constraints. An Inceptisol soil was amended with dolomitic lime (2 g dolomitic lime kg^–1 soil) to achieve low acidity (pH = 5.9) and without lime (zero lime kg^–1 soil,) to achieve high acidity (pH = 4.8) levels to evaluate bean genotypes. At both acidity levels, genotypes differed significantly in shoot dry weight and grain yield. Shoot dry weight and grain yield were significantly decreased at the high acidity level compared to the low acidity level. Grain yield was more sensitive to soil acidity than shoot dry weight. Hence, grain yield was used in determination of tolerance index (GTI) to differentiate the range of soil acidity tolerance among bean genotypes. Based on a GTI value, 55% of the genotypes were classified as tolerant, 40% classified as moderately tolerant, and the remaining were grouped as susceptible to soil acidity. The genotype CNFC 10410 was most tolerant and genotype CNFP 10120 was most susceptible to soil acidity. Number of pods and grain harvest index were significantly and positively associated with grain yield. The improvement in grain yield in low acidity may be related to reduction of toxic levels of soil aluminum (Al³⁺) and hydrogen (H⁺) ions by lime addition. At harvest, soil extractable phosphorus (P) and potassium (K) increased with the reduction of soil acidity, and this might have contributed to the better nutrition of beans and lead to higher growth.     

Genetic variation for tolerance to post-emergence herbicide,imazethapyr in lentil (Lens culinaris Medik.)

Weeds pose a serious constraint to lentil production. Identification and deployment of post-emergence herbicide tolerance in improved varieties can help reduce the production cost and increase the productivity and area under lentil cultivation. Imazethapyr, a post-emergence herbicide was tested on 180 lentil genotypes for two consecutive years. Significant variation among the genotypes was observed for tolerance to imazethapyr. On a 1–5 scale, 12 genotypes were found tolerant, 46 moderately tolerant, 112 sensitive and 10 highly sensitive during the first season, and 11 genotypes were found tolerant, 51 moderately tolerant, 110 sensitive and 8 highly sensitive during the second season. Based on the first year’s result, 30 genotypes, representing tolerant, moderately tolerant, sensitive and highly sensitive reactions, were evaluated to determine the effect of herbicide on morpho-physiological and yield traits. The adverse effect of imazethapyr was significant on growth and yield attributes of lentils. Five genotypes namely LL699, LL1397, IPL406, EC78452 and LL1203 demonstrated tolerance to imazethapyr with limited phytotoxic effect on various morpho-physiological traits. These genotypes showed less reduction (<19%) for seed yield in imazethapyr treated plots as compared to control. These genotypes offer scope for developing post-emergence herbicide tolerant cultivars in lentil.     

小麦苗期耐低氮基因型的筛选与评价

氮是作物吸收的第一大必需营养元素, 对作物生长发育具有不可替代的作用。大量研究表明, 不同基因型小麦对氮的吸收利用能力不同, 培育氮高效小麦品种是提高氮利用效率的根本途径, 而发掘耐低氮小麦种质资源是小麦氮高效育种的基础。为此, 本研究以30 个小麦-冰草远缘杂交的高代品系, 1 个小麦-黑麦远缘杂交的T1BL·1RS 易位系, 2 个"小偃54"×"京411"重组自交系群体中的品系, 以及13 个生产上的主栽品种为试验材料, 通过低氮胁迫和正常供氮2 个处理的苗期水培试验, 进行了耐低氮基因型的筛选与评价。方差分析显示, 13 个氮效率相关性状在2 种氮水平之间及各小麦基因型之间的差异均达到显著或极显著水平。主成分分析显示, 前3 个主成分累积贡献率达到81.2%, 已包含了大部分信息, 能够基本反映整体状况。其中, 相对茎叶吸氮量、相对植株吸氮量、相对根冠比、相对茎叶干重、相对植株干重、相对茎叶氮利用效率、相对根含氮量在3 个主成分中占较大的比重。综合评价结果显示, 在33 个小麦远缘杂交品系中08B41 得分最高, 为1.60,为最耐低氮的品系; 13 个主栽品中"科农9204"得分最高, 为2.10, 为耐低氮的品种。聚类分析显示, 46 份基因型小麦可划分为3 大类: 耐低氮型(15 份)、中间型(22 份)和低氮敏感型(9 份)。筛选出08B41、XJ19-1、08B8、08B10、08B13、08B25、WR9603、08B2、08B5 共9 份耐低氮远缘杂交高代品系, 及"科农9204"、"邯7086"、"河农827"、"石麦18"、"石4185"、"石新733"共6 份耐低氮主栽品种。这些耐低氮的基因型可作为小麦营养高效育种的种质资源, 本文并对小麦近缘种属在小麦营养高效遗传改良中的作用进行了讨论。     

低磷胁迫对不同磷效率基因型烟草苗期生长及生理特征的影响

为揭示不同磷效率烟草对低磷胁迫的响应机理,以磷高效且耐低磷基因型K326和云烟105及磷低效且低磷敏感基因型G28和中烟101为试验材料,设置低磷(0.01 mmol·L^-1,LP)和正常磷(1.00 mmol·L^-1,NP)2个处理,研究不同磷效率基因型烟草苗期主要农艺性状及生理指标对低磷处理的反应。结果表明,磷高效基因型的农艺指标(株高、地上部干重、根系干重等)在2种处理中均显著高于磷低效基因型,表明磷高效基因型在LP和NP水平下均能较好生长,对磷素具有较高的吸收或利用效率;在LP下,磷高效基因型的主根长增幅较大,干重、株高等降幅较小,即磷高效品种的生长受低磷影响较小,耐低磷性较强。在生理指标方面,LP条件下磷高效基因型的3种保护酶[过氧化氢酶(CAT)、超氧化物歧化酶(SOD)、过氧化物酶(POD)]和酸性磷酸酶(ACP)活性及可溶性糖和游离脯氨酸含量的增幅较磷低效基因型大,丙二醛(MDA)含量的增幅较小,可溶性蛋白含量、根系活力的降幅较小,水培营养液的pH值降幅较大;磷高效基因型的农艺性状及生理指标的耐低磷指数均高于磷低效基因型。综上,在低磷胁迫中,磷高效基因型烟草具有较强的活性氧清除能力,可累积较多渗透调节物质以维持细胞渗透势,较好地保护细胞,增强体内ACP活性,提高对磷素的吸收利用效率,维持自身的正常生长与代谢。本研究结果为烟草磷素高效吸收利用提供了一定的理论依据。     

Ozone tolerance related to flavonol glycoside genes in soybean

Ozone toxicity can reduce soybean yields by an estimated 5 to 20%. The most economical and practical solution to the problem would be to use ozone‐tolerant cultivars. Because ozone toxicity is an oxidative stress, one would expect that plants having higher concentrations and proper kinds of antioxidants would be more tolerant. To test this hypothesis, 20 soybean lines or cultivars varying in contents of flavonol glycosides (naturally occurring antioxidants) were tested for ozone tolerance in a fumigation chamber and in phyto‐toxic concentrations of ozone in ambient, unfiltered, air in a greenhouse. In general, ozone tolerance was associated with the presence of kaempferol glycosides, particularly K3 through K6 and K9. Lines containing no kaempferol glycosides (OX942 & OX281) were among the most sensitive to ozone stress. The K9 compound has been associated with reduced numbers of stomata, drought tolerance, and slower growth rates, and this could reduce ozone absorption and toxicity, or K9 may be more effective in detoxifying ozone than other glycosides. Lee soybean was more tolerant to ozone and to manganese (Mn) toxicity (also an oxidative stress) than Forrest. Cross tolerances of plant genotypes to these two stresses deserve additional study. Among cultivars compared, Mukden was ozone tolerant, Columbia and Harosoy were sensitive, and Blackhawk was moderately sensitive.     

RESPONSE OF NON-NODULATING,NODULATING, AND SUPER-NODULATING SOYBEAN GENOTYPES TO POTASSIUM FERTILIZER UNDER WATER STRESS

Soil moisture is a principal environmental factor limiting legume productivity in the tropics and sub-tropics. A pot experiment was conducted at the wire house of National Research Centre, Cairo, Egypt to study how potassium (K) fertilizer can mitigate the adverse effect of water stress. Three Japanese soybean (Glycine max L.) genotypes, non-nodulating (NN) (En 1282), nodulating (N) (Eneri) and super-nodulating (SN) (En-b0-1) were grown under two potassium fertilizer levels (25 and 150 mg kg^?1 soil as K1 and K2, respectively). The water stress (WS) was conducted for eight days. WS significantly reduced nodules numbers and weights, shoot dry weight, relative water content, seed yield, oil, total carbohydrate contents while protein was significantly increased in the three soybean genotypes compared with well-watered (WW). Water stress and/or K treatments caused significant increase in both free amino acids and proline as well as shoot nitrogen in the three soybean genotypes.     

Growth,morphological and yield responses of irrigated wheat (Triticum aestivum L.) genotypes to water stress

Water shortages is a major constraint in wheat production in South Africa. It is important therefore to assist irrigated wheat farmers to identify water stress tolerant growth stages in irrigated wheat genotypes. This study evaluated new wheat genotypes for water stress at different growth stages. An 8 (genotypes) × 2 (water treatments) × 3 (growth stages) factorial experiment was laid out in a randomised complete block design with three replicates. The results indicated that plant height was not affected (p > .05) by water stress at tillering and grain filling. Water stress imposed at the tillering stage reduced the number of fertile tillers (p < .05) in susceptible genotypes while at the flowering and grain filling stages all genotypes were tolerant (p > .05). Aboveground biomass was only affected (p < .05) by water stress imposed at the tillering stage. Water stress reduced grain yield on the genotypes where stress was imposed at the tillering stage (p < .05); whereas when stress was imposed at flowering and grain filling the grain yield was not reduced (p > .05). This study provided evidence to suggest that most genotypes were tolerant to water stress at the flowering and grain filling stages.     

IDENTIFICATION OF MAIZE GENOTYPES WITH HIGH TOLERANCE OR SENSITIVITY TO PHOSPHORUS DEFICIENCY

Soil culture containing phosphorus (P) supply of different levels may be used to screen maize genotypes for resistance to P deficiency. Relative dry weight and P-deficiency symptom level were proven to be fast and efficient indicators for screening of the P-deficiency tolerant genotypes at the stage of seedling. Two maize genotypes, HZS15 and HZS03 were identified as highly sensitive genotypes under P deficiency, simultaneously, HZT32 and HZT33 had extremely high tolerance to P deficiency. The yield experiment confirmed the reliability of this selecting strategy at the stage of seedling. The yield analysis revealed that HZT32 and HZT33 had higher average yield of each plant and thousand-grain weight than those of HZS15 and HZS03. Successively, responses of four genotypes to P deficiency were investigated with simplified hydroponic culture system. Elongated taproot and increased ratio of root to shoot were observed in all four genotypes. However, two P-deficiency-tolerant genotypes had higher ratio of root to shoot than those in P-deficiency-sensitive genotypes. Phosphorus efficiency analysis revealed that under P deficiency HZT33 had higher P absorption efficiency than those of other three genotypes, and two P-deficiency-tolerant genotypes had higher P use efficiency than that of two P-deficiency-sensitive genotypes. These results indicated that the tolerance of HZT32 and HZT33 to P deficiency might primarily be ascribed to high P use efficiency. Moreover, high P absorption efficiency contributed partially to the tolerance of HZT33 under P deficiency. Further research is needed to elucidate the complex correlation between other physiological traits and P efficiency.     

Lowland Rice Genotypes Evaluation for Potassium-Use Efficiency

Lowland rice significantly contributes to world as well as Brazilian rice production and information on genotypes potassium-use efficiency is limited. A greenhouse experiment was conducted with the objective to evaluate lowland rice genotypes for potassium (K)–use efficiency. Ten genotypes were evaluated at 0 mg K kg^?1 (low) and 200 mg K kg^?1 (high) of soil. Grain yield and shoot dry weight were significantly affected by K as well as genotype treatments. Genotypes CNAi 8860, CNAi 8859, BRS Fronteira, and BRS Alvorada were the best in relation to K-use efficiency because they produced best grain yield at low as well as at higher K levels. Shoot dry weight, number of panicles per pot, and 1000-grain weight had highly significant (P < 0.01) association with grain yield. Spikelet sterility, however, had significant negative association with grain yield. These plant parameters were mainly influenced by genotypes, indicating importance of selecting appropriate genetic material for improving grain yield. Soil K depletion was significant at harvest, suggesting large amount of K uptake by lowland rice genotypes.     

Genetic and Environmental Effects on Dough Mixing Characteristics and Agronomic Performance of Diverse Hard Red Winter Wheat Genotypes

Wheat (Triticum aestivum L.) genotypes with short mixing times usually have low mixing tolerance values, which make them more sensitive to overmixing in commercial bread production. In this study, we evaluated the genotypic and environmental effects on agronomic performance and end‐use quality of 27 experimental genotypes (hereafter referred to as mixing tolerant genotypes) which were identified in an initial screen as having short mixing times and good mixing tolerances to 1) determine whether genotypes identified in a preliminary end‐use quality screen as lines with usually long tolerances but short mixing times were due to their genotype (G), the environment (E), or G × E; and as these results were unusual, 2) determine whether or not our initial screen predicts end‐use quality, and 3) determine the stability of both agronomic and end‐use quality traits. The 27 genotypes and five check cultivars were grown in a randomized complete block design with two replicates in nine environments in 1997 and 1998. All plots were harvested for grain yield. The harvested grain from the first replicate and random genotypes from the second replicate were micromilled to produce flour samples for evaluation of flour yield, protein content, and mixograph mixing time and mixing tolerance values. Seed diameter, thousand kernel weight, and kernel hardness were also measured in three environments. Environment, G, and G × E interaction effects (mainly changes in magnitude) were significant for most agronomic and end‐use quality parameters. Our initial screen, which had identified 27 genotypes, was partially effective in identifying genotypes that have shorter mixing time values compared with their mixing tolerance values. We identified four genotypes (15%) from the mixing tolerant genotypes that had a good mixing tolerance value and relatively shorter mixing time, as did the released cultivars ‘Agate’ and ‘Scout 66’. However, mixing characteristics values of all genotypes fell within the acceptable limits, indicating our screen effectively identified genotypes with acceptable quality. Mixing tolerant genotypes, which had been identified as having short mixing time scores and long mixing tolerance scores, were considered stable across environments.     

Tolerance of chickpea (Cicer arietinum L.) lines to root-knot nematode, Meloidogyne javanica (Treub) Chitwood

The root-knot nematode, Meloidogyne javanica (Treub) Chitwood is an important parasite of chickpea (Cicer arietinum L.). Four chickpea genotypes were evaluated for tolerance to M. javanica in naturally infested fields at three locations. Each genotype was evaluated for number of galls, gall size, root area covered with galls and number of egg masses produced. All the cultivars were susceptible or highly susceptible. Seed yield, weight of 100 undamaged seeds, total dry matter and plant height were compared with checks. Chickpea cultivar Annigeri and a local check were used as nematode susceptible checks in all locations. The four promising nematode tolerant genotypes produced significantly greater yield and total dry matter than the checks in fields naturally infested with M. javanica at three locations. These M. javanica tolerant lines represent new germplasm and they are available in the chickpea genebank at the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) bearing the identification numbers ICC 8932, ICC 11152, ICCV 90043 and ICCC 42.     

冷型小麦氮素吸收积累特性的研究

2002至2004年,通过田间小区试验,研究了4种施肥条件下(不施肥、单施磷肥、单施氮肥和氮磷配施)冠层温度持续偏低的冷型小麦氮素吸收积累特性。供试小麦品种为小偃6号、陕229、NR9405和9430,前两者为冷型小麦品种,后两者为暖型小麦品种。结果表明,花前冷型小麦叶片具有较高的氮素积累量;花后氮素吸收积累量在单施磷肥、单施氮肥和氮磷配施条件下比暖型小麦分别高168.6%、144.6%和217.4%。成熟期冷型小麦子粒中氮素积累量大,功能叶片中氮素残留量多。冷型小麦叶片较高的氮素含量为维持叶片较高的光合速率奠定了良好的氮营养基础;花后氮素吸收积累量较多的特点,与冷型小麦灌浆结实期具有较高的代谢生理活性,根系吸收氮能力强有密切关系。