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1.
小麦旗叶光呼吸对光强和CO2浓度的响应   总被引:1,自引:0,他引:1  
为给C3作物光呼吸等光合参数以及光响应模型和CO2响应模型的研究提供参考,定量研究了小麦花期旗叶光呼吸速率对光强和CO2浓度的响应。结果表明,在21%和2%O2下小麦旗叶光饱和点分别为1 960.629和2 030.120 μmol·m-2·s-1。在较弱光强(小于800 μmol·m-2·s-1)下,小麦的总光呼吸速率(Rpt)与表观光呼吸(Rpa)均随着光强的升高而增大;当光强大于800 μmol·m-2·s-1时,RptRpa趋于稳定;整体上,不同光强下RptRpa之间差异较小(P>0.05),这主要是由于在380 μmol·mol-1 CO2下,光呼吸的CO2回收利用率较低。饱和光强下,Rpa随着CO2浓度的增加呈先上升后下降的趋势,Rpa最大值(Rpmax)所对应的外界CO2浓度为600 μmol·mol-1,而Rpt则随着CO2浓度的升高而降低;在低浓度CO2(小于380 μmol·mol-1)条件下,RptRpa之间差异显著(P<0.05)。Rpt与羧化速率的比值(Rpt /Vc)随着胞间CO2浓度的升高而呈下降的趋势,而不同光强下Rpt /Vc相对稳定,整体上未达到显著水平(P>0.05)。  相似文献   

2.
玉米回交后代群体中供体基因组成分分析   总被引:1,自引:1,他引:0  
以郑58为受体亲本,昌7-2为供体亲本,通过杂交、回交和79对亲本间有多态的SSR标记,分析BC2F1和BC3F1世代供体的基因组成分。结果表明:BC2F1世代单株内的供体染色体片段数平均为11.4个,BC3F1世代为4.8个,从BC2F1到BC3F1单株内的供体染色体片段数减少了57.6%;BC2F1世代单株内的供体染色体片段长度平均为99.3 cM,BC3F1世代为87.1 cM,BC3F1较BC2F1减少了12.3%;BC2F1世代单株内的供体基因组大小平均为1 132.8 cM,BC3F1世代为421.4 cM,BC3F1较BC2F1减少了62.8%。  相似文献   

3.
密度对不同株型玉米光合特性及产量的影响   总被引:21,自引:9,他引:12  
胡萌  魏湜  杨猛  矫海波  魏玲  王燚  吉彪 《玉米科学》2010,18(1):103-107
对不同密度条件下3个不同株型春玉米的光合特性及产量进行了研究。结果表明,随密度增加叶面积指数(LAI)、初始荧光(F0)上升,单株功能叶片光合速率(Pn)、PSⅡ的潜在活性(Fv /F0)、PSⅡ最大光化学量子产量(Fv /Fm)下降;产量构成因素表现为单位面积有效穗数先上升后下降,穗粒数下降,百粒重变化因品种而异。先玉335、金玉4号和吉农大302最高产量分别为9 638.45、8 523.94、8 330.92 kg/hm2;先玉335最适播种密度为75 000株/hm2,吉农大302为60 000~67 500株/hm2,金玉4号为45 000株/hm2。先玉335群体产量与LAI、单株F0呈正相关,与单株Pn、Fv /Fm、Fv /F0呈负相关;吉农大302与金玉4号群体产量与LAI、单株F0呈负相关,与单株Pn、Fv /Fm、Fv /F0呈正相关,且金玉4号的相关程度要高于吉农大302。  相似文献   

4.
为了探究不同缓释肥配比与基本苗互作对冬小麦生产的影响,以中筋小麦扬麦25为材料,于2019-2020年在江苏省仪征市进行田间试验,设置100%普通尿素(S1)、50%缓释肥与50%尿素配施(S2)、100%缓释肥(S3)3种施肥处理及4种氮密模式[施氮(纯N)量225 kg·hm-2、密度225×10株·hm-2(A1);施氮量191.25 kg·hm-2、密度258.75×10株·hm-2(A2);施氮量157.5 kg·hm-2、密度292.5×10株·hm-2(A3);施氮量123.75 kg·hm-2、密度326.25×10株·hm-2(A4)],研究不同处理对冬小麦产量及其构成因素、品质的影响。结果表明,氮肥类型和氮密模式均对产量有极显著效应;与 A1处理比较,A2处理的穗数和穗粒数较高,千粒重下降,继续增加种植密度、减少施氮量后,穗数与穗粒数显著下降;产量以S2A2与 S3A2组合处理较高。S2与S3处理的氮肥利用率与氮素农学效率均优于S1处理,A4模式的氮素农学效率最高,不同氮密模式处理间的氮肥利用率差异不显著。氮肥类型与氮密模式对出粉率、容重与硬度影响不显著,对湿面筋含量、沉降值、面团形成时间、面团稳定时间与吸水率有极显著影响, A1和 A2处理的品质表现较好,S2与S3处理的小麦二次加工品质优于S1处理;氮肥类型与氮密模式互作对籽粒蛋白质含量与产量有极显著影响。本试验条件下,50%缓释肥与50%尿素配施或100%缓释肥处理下,施氮量191.25  kg·hm-2、密度258.75×10株·hm-2(A2),施用基肥与返青肥,有利于小麦减氮稳产、改善品质、提高氮肥利用率。  相似文献   

5.
为了阐明壳寡糖调节小麦早期生长发育的机理,以室内培养的方法研究了四种浓度的壳寡糖对小麦幼苗早期生长的影响,同时利用组化染色和分光光度计法分别检测了其对根尖和叶片中H2O2和O2-含量的影响。结果表明,1 μg·mL-1壳寡糖可以显著促进小麦根和幼苗的生长,而10 μg·mL-1壳寡糖则抑制其生长;壳寡糖对小麦幼苗叶片和根尖中的H2O2和O2-含量影响不同,在根尖中1 μg·mL-1壳寡糖可以增加H2O2和O2-含量,10 μg·mL-1壳寡糖可以增加H2O2含量而降低了O2-含量;在叶片中1 μg·mL-1壳寡糖对H2O2和O2-无明显影响,10 μg·mL-1壳寡糖可以降低H2O2含量而不改变O2-含量。壳寡糖对小麦幼苗叶片中的丙二醛和可溶性蛋白质含量影响不大。  相似文献   

6.
为给小麦株高和产量的遗传改良提供参考依据,利用 Rht-B1b Rht-D1b基因的STS分子标记BF/MR1和BF/WR1、DF1/MR2和DF2/WR2,以及 Rht8基因的微卫星标记Xgwm261,对237份不同生态区秋播小麦材料进行分子标记检测,并分析 Rht-B1b Rht-D1b Rht8对株高及产量相关性状的影响。结果表明:(1)在分布频率方面, Rht-B1b Rht-D1b Rht8在秋播冬小麦中的频率较高,其中携带 Rht-B1b Rht-D1b Rht8的小麦材料分别占比16.5%、47.9%和44.1%;聚合两个矮秆基因( Rht-D1b+Rht8 Rht-B1b+Rht8 Rht-B1b+ Rht-D1b)的小麦材料占比25.4%;聚合三个矮秆基因(Rht-B1b+Rht-D1b+Rht8)的小麦材料占比2.1%;(2)在分布特点方面,不同冬麦区存在一定偏好性:北部冬麦区、黄淮冬麦区、长江中下游冬麦区均以 Rht-D1b Rht8 Rht-D1b+Rht8为主;西南冬麦区以 Rht-B1b Rht-D1b Rht8为主,西南冬麦区以 Rht-B1bRht-D1bRht8为主;(3)在降秆效应方面,降秆效果从强到弱依次为( Rht-B1b+Rht-D1b+Rht8)>( Rht-D1b+Rht8)> ( Rht-B1b+Rht8)> Rht-D1b> Rht-B1b> Rht8;(4)在产量结构特点方面, 携带 Rht-D1b Rht8的材料总体上具有较高的千粒重和单位面积穗数,携带 Rht-B1b的材料具有较高的穗粒数,但矮秆基因本身与产量因子间无显著的遗传相关性。  相似文献   

7.
为探究长期施氮条件下种植密度对冬小麦品质特性和氮肥利用的调控作用,在长期定位试验的基础上,2020-2021年度采用裂区试验设计,主区为施氮量,设75 kg·hm-2(N75)、150 kg·hm-2(N150)、225 kg·hm-2(N225)和300 kg·hm-2(N300) 4个水平;副区为种植密度,设225×104 株·hm-2(D225)、300×104株·hm-2(D300)、375×104株·hm-2(D375)、450×104株·hm-2(D450)和525×104株·hm-2(D525)5个水平;分析了不同施氮条件下种植密度对石4366产量、粉质特性、RVA特性、拉伸特性及氮肥利用率的影响。结果表明,不同施氮量和密度组合下籽粒产量和品质相关指标有较大差异,施氮量对氮肥农学效率和氮肥偏生产力有显著影响。小麦产量随着施氮量的升高而增加,施氮量225 kg·hm-2、密度范围375×104~525×104株·hm-2和施氮量300 kg·hm-2、密度范围225×104~450×104株·hm-2组合下均能获得较高产量。蛋白质含量、容重和湿面筋含量随着施氮量增加呈升高趋势;稳定时间和粉质质量指数随着施氮量增加呈先升高后降低的趋势,N225下粉质参数最高。小麦籽粒品质和面粉粉质指标均随种植密度的增加而增加。施氮量225 kg·hm-2、密度525×104株·hm-2组合是小麦粉质指标最优组合。淀粉RVA参数在施氮量225 kg·hm-2、密度225×104株·hm-2处理下最好。拉伸特性在施氮量225 kg·hm-2、密度450×104~525×104株·hm-2组合和施氮量300 kg·hm-2、密度225×104株·hm-2组合下较好。氮肥农学效率和氮肥偏生产力在施氮量225 kg·hm-2、密度375×104~525×104株·hm-2组合下较高。综合籽粒产量、品质相关指标和氮肥利用效率的结果,本试验条件下,施氮量225 kg·hm-2、种植密度450×104~525×104株·hm-2可作为石4366高产、优质的较佳肥密组合。  相似文献   

8.
高温胁迫下镁对小麦旗叶光合特性及产量的影响   总被引:1,自引:0,他引:1  
为了解施镁对小麦后期高温胁迫的缓解效应,采用盆栽试验方法,以自然条件为对照(昼夜温度分别为26和16 ℃),研究了灌浆期花后14~20 d 和花后21~27 d高温胁迫(昼夜温度分别为32和22 ℃)下,施镁(20 kg·hm-2)对小麦产量和旗叶光合特性的影响。结果表明,高温胁迫显著降低了小麦产量,且以花后21~27 d高温胁迫影响最大;施镁能显著增加穗粒数、千粒重和籽粒产量。高温胁迫降低了旗叶叶绿素含量、净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)、光化学效率(Fv/Fm)和实际光量子产量(ΦPSⅡ),各指标均以花后21~27 d高温处理降幅最大,而胞间二氧化碳浓度(Ci)则表现出相反趋势;相同温度处理下,施镁则显著提高了旗叶叶绿素含量、PnGsTrFv/FmΦPSⅡ,表明镁素施用能有效缓解花后高温对叶片光合能力的伤害,有助于光合产物的积累和产量的形成。  相似文献   

9.
为给甘肃河西绿洲灌区啤酒大麦垄作沟灌栽培的水肥管理提供参考,通过裂区试验,设置4个不同灌溉定额(1 500 m·hm-2、2 100 m·hm-2、2 700 m·hm-2和3 300 m·hm-2)和3个不同施肥水平(N 75 kg·hm-2+P2O556.25 kg·hm-2、 N 150 kg·hm-2+P2O5112.5 kg·hm-2、N 225 kg·hm-2+P2O5168.75 kg·hm-2),研究了灌水和施肥对垄作沟灌栽培啤酒大麦产量及水分利用效率的影响。结果表明,灌溉定额、施肥量及水肥互作对啤酒大麦的产量和水分利用效率均有明显影响。当灌溉定额从1 500 m·hm-2增大到2 700 m·hm-2时,啤酒大麦千粒重提高5.36 g,成穗数增加1.16×106·hm-2,增产57.99%,水分利用效率提高24.12%;灌水量超过2 700 m·hm-2时,增产效果不明显。在N 75~150 kg·hm-2、P2O556.25~112.5 kg·hm-2范围内,增施肥料有利于啤酒大麦千粒重和穗粒数增加,并显著提高产量和水分利用效率。在灌溉定额2 700 m·hm-2、纯N 150 kg·hm-2、P2O5 112.5 kg·hm-2条件下,垄作沟灌栽培啤酒大麦的产量和水分利用效率分别为6 239.84 kg·hm-2和13.33 kg·mm-1·hm-2,水肥利用效果和经济效益相对较优。  相似文献   

10.
施硒对不同密度春小麦产量和籽粒硒含量的影响   总被引:2,自引:0,他引:2  
为确定新疆富硒小麦的最适宜种植密度和施硒量,在种植密度为450万株·hm-2(D1)、600万株·hm-2(D2)、750万株·hm-2(D3)条件下,在灌浆前期分别喷施5个浓度的亚硒酸钠,折合纯硒为0 g·hm-2(Se1)、15 g·hm-2(Se2)、30 g·hm-2(Se3)、45 g·hm-2(Se4)、60 g·hm-2(Se5),分析不同处理对春小麦产量及其构成因素、籽粒硒含量、硒累积量、吸收利用率及籽粒氮、磷、钾含量的影响。结果表明,D2处理下小麦的成穗数、穗粒数、穗长、千粒重、产量均最佳,分别为663.00×104·hm-2、45.37、10.45 cm、44.38 g、7 291.38 kg·hm-2,产量较D1和D3分别提高了13.24%和9.89%。施硒可使小麦产量增幅达4.59%~16.21%;施硒后籽粒中有机硒含量达140.90~346.32 μg·kg-1,占总硒含量的79.17%~82.47%。密度对籽粒总硒、有机硒、无机硒含量、籽粒硒强化指数没有明显影响,但对籽粒硒累积量、硒利用率影响显著,其中D2处理下硒累积量最大。密度和施硒互作对硒累积量影响显著,但对其他指标影响均不显著。施硒能显著增加籽粒氮、磷含量,降低钾含量;Se4处理下籽粒的氮、磷含量最高,比不施硒平均增加4.55%、16.67%,Se1处理籽粒钾含量最高,达0.28%~0.29%。在本试验条件下,小麦最优种植密度和施硒量分别为600万株·hm-2和45 g·hm-2。  相似文献   

11.
Teas of plant origin traditionally consumed by the Mountain Pima of Chihuahua, Mexico, were analyzed for mineral nutritional content. Fe, Cu, Zn, Ca, and Mg composition was determined for native teas made from shoots ofTagetes lucida, T. filifolia, Elytraria imbricata, andHolodiscus dumosus, and from root xylem ofCeanothus depressus andPhaseolus ritensis. Native uses of these teas are also described.  相似文献   

12.
13.
Summary The effects of the leaves of five plant species, one from each of the generaAmbrosia, Anemone, Eupatorium, Eucalyptus andLantana, on potato tuber moth were investigated under indigenous storage conditions at the Central Potato Research Station, Shillong (1800 m above sea level). Their action was compared with that of a biological insecticide (spores ofBacillus thuringiensis), a chemical insecticide (carbaryl), and an untreated control. The data collected after six months storage on tuber damage, sprout damage and the rotting indicated that the leaves ofLantana aculeata provided most protection to the tubers, reducing damage from over 70% in the check to below 5%, and sprout damage from over 45% to below 3%. Next best wasEucalyptus globulus followed byB. thuringiensis. They may be used on tubers stored for table use or for seed as they had no adverse effect on germination or on the yield of a subsequent crop.  相似文献   

14.
Summary

The efficiency of N fertilizers is usually poor; often less than 50% of the applied N is taken up by the crop. This review focuses on various N fertilizers with respect to the significance of different N loss pathways, namely (i) ammonia volatilization, (ii) dinitrogen and nitrogen oxide emissions, and (iii) nitrate leaching. Further, the significance of biological N immobilization, ammonium fixation and, finally, the impact of nitrate vs. ammonium uptake on crop yield are also discussed. The reviewed literature shows that N fertilizers may differ markedly in their susceptibility to losses. There is, however, considerable scope to improve N efficiency of each N source by proper N management practices.  相似文献   

15.
16.
Health authorities worldwide have consistently recommended the regular consumption of marine fishes and seafood to preserve memory, sustain cognitive functions, and prevent neurodegenerative processes in humans. Shrimp, crabs, lobster, and salmon are of particular interest in the human diet due to their substantial provision of omega-3 fatty acids (n-3/PUFAs) and the antioxidant carotenoid astaxanthin (ASTA). However, the optimal ratio between these nutraceuticals in natural sources is apparently the key factor for maximum protection against most neuro-motor disorders. Therefore, we aimed here to investigate the effects of a long-term supplementation with (n-3)/PUFAs-rich fish oil, ASTA-rich algal biomass, the combination of them, or krill oil (a natural combination of both nutrients) on baseline redox balance and neuro-inflammation indexes in cerebellum and motor cortex of Wistar rats. Significant changes in redox metabolism were only observed upon ASTA supplementation, which reinforce its antioxidant properties with a putative mitochondrial-centered action in rat brain. Krill oil imposed mild astrocyte activation in motor cortex of Wistar rats, although no redox or inflammatory index was concomitantly altered. In summary, there is no experimental evidence that krill oil, fish oil, oralgal biomass (minor variation), drastically change the baseline oxidative conditions or the neuro-inflammatory scenario in neuromotor-associated rat brain regions.  相似文献   

17.
Wheat bran is a composite material made of several layers, such as pericarp, testa and aleurone. It could be fractionated into purified fractions, which might either be used as food ingredients, or serve as a starting material for extraction of bioactive compounds. The aim of this work was to evaluate the potential of using electrostatic separation as a way to obtain purified fractions from wheat bran. Ultrafine-ground bran obtained either by cryogenic grinding or by grinding at ambient temperature was used as starting material. The ultrafine bran was then charged by tribo-electrification and introduced in a chamber containing two high voltage electrodes, where bran particles were separated depending on their acquired charge, allowing positively and negatively charged fractions to be collected separately. The particle size distribution, microstructure and biochemical composition of the obtained fractions were studied. The charge of the particles was influenced by their biochemical composition: particles rich in highly branched and cross-linked arabinoxylans (pericarp) were separated from particles rich in β-glucan, ferulic acid and para-coumaric acid (aleurone cell walls). The testa and the intracellular compounds from aleurone were not highly charged, neither positively nor negatively. The most positively charged fraction represented 34% of the initial bran, and contained 62% of the ferulic acid present in the initial bran. The yield of the separation process was good (5.4% loss), and could be further increased.  相似文献   

18.
Summary The in vitro antimicrobial activity of extracts from accessions ofSolanum commersonii Dun. collected in the south of Uruguay was investigated against five microorganisms including the pathogenRalstonia solanacearum. A total of 30 extracts corresponding to organic and aqueous extracts were studied. Interestingly, most of the positive results for growth inhibition were againstR. solanacearum. The extracts were also analyzed for the presence of glycoalkaloids and lectins. Six of the ten aqueous extracts showed lectin presence and a wide variation in the type and amounts of glycoalkaloids, was found. Results indicate that there is no clear relationship between the antimicrobial activity against the five microorganisms screened and the presence or amounts of lectins and glycoalkaloids, traditionally regarded as possible antimicrobial metabolites in theSolanum genus, which indicates the presence of as yet unidentified antimicrobial compounds.  相似文献   

19.
Novel food and non-food uses for sorghum and millets   总被引:4,自引:3,他引:4  
Sorghum and millets have considerable potential in foods and beverages. As they are gluten-free they are suitable for coeliacs. Sorghum is also a potentially important source of nutraceuticals such antioxidant phenolics and cholesterol-lowering waxes. Cakes, cookies, pasta, a parboiled rice-like product and snack foods have been successfully produced from sorghum and, in some cases, millets. Wheat-free sorghum or millet bread remains the main challenge. Additives such as native and pre-gelatinised starches, hydrocolloids, fat, egg and rye pentosans improve bread quality. However, specific volumes are lower than those for wheat bread or gluten-free breads based on pure starches, and in many cases, breads tend to stale faster. Lager and stout beers with sorghum are brewed commercially. Sorghum's high-starch gelatinisation temperature and low beta-amylase activity remain problems with regard to complete substitution of barley malt with sorghum malt . The role of the sorghum endosperm matrix protein and cell wall components in limiting extract is a research focus. Brewing with millets is still at an experimental stage. Sorghum could be important for bioethanol and other bio-industrial products. Bioethanol research has focused on improving the economics of the process through cultivar selection, method development for low-quality grain and pre-processing to recover valuable by-products. Potential by-products such as the kafirin prolamin proteins and the pericarp wax have potential as bioplastic films and coatings for foods, primarily due to their hydrophobicity.  相似文献   

20.
Pulque is made by fermenting the agave sap or aguamiel of Agave atrovirens with a whole array of microorganisms present in the environment including several lactic acid bacteria and yeasts such as Saccharomyces cerevisiae. Ascorbic acid was determined in pulque and aguamiel, respectively. Phytase activity in lees, liquid and freeze-dried pulque was assayed by measuring the appearance of phosphate from phytate by a colorimetric method likewise phosphate from phytate present in fresh corn tortilla was measured after in vitro incubation with pulque. Iron, zinc, calcium, magnesium and selenium contents were measured in pulque and corn tortilla as well as in nixtamalized corn flour (NCF), the latter is used to make instant tortilla, since corn provides most of the energy as well as most of the phytate in the Mexican rural diet. Pulque showed phytase activity but much less ascorbic acid and iron than previously reported; additionally, phytase in pulque hydrolyzed most of phytate’s corn tortilla. Lees, which is mostly made of pulque’s microbiota, significantly accumulated iron and zinc but no selenium. NCF was fortified with iron by the manufacturers but poorly blended. There were significant differences on selenium content between tortillas samples, apparently some soils in central Mexico are selenium deficient. Moderate pulque intake appears to increase the bioavailability of iron and zinc bound by phytate in corn.  相似文献   

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