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1.
为了解不同麦类种质的抗旱性,进一步发掘小麦近缘种的优势性状以改良小麦品种,2018—2019年在兰州新区和武威黄羊镇对引自国际玉米小麦改良中心(CIMMYT)的灌溉圃小麦、干旱半干旱圃小麦、合成小麦、硬粒小麦和小黑麦设置了正常灌溉和水分胁迫两种处理,在拔节期、抽穗期、灌浆期对心叶或旗叶进行了叶绿素荧光动力学参数测定,并进行了农艺性状鉴定和产量测定,分析了不同生育期叶绿素荧光参数的变化及其与抗旱指数的关系。结果表明,水分胁迫对不同麦类作物产量构成因素的影响程度不同导致其抗旱性有差异。水分胁迫下,PSⅡ潜在活性(Fv/Fo)、PSⅡ反应中心最大光化学效率(Fv/Fm)、PSⅡ实际光化学量子效率(Fq/Fm)均较正常灌溉下降低,而非光化学淬灭系数(NPQ)升高。随小麦发育进程推移,Fv/FoFv/FmFq/Fm呈先升后降的趋势,NPQ呈上升趋势。荧光参数的变化说明,干旱胁迫导致PSⅡ结构受损,反应中心受到破坏,光能转化效率降低,电子传递受阻。灰色关联度分析显示,灌浆期荧光参数与抗旱指数的关联度较高,其次为抽穗期、拔节期,各荧光参数与抗旱指数关联度为Fv/Fm>Fq/Fm>Fv/Fo>NPQ。基于农艺性状、抗旱指数和叶绿素荧光参数,得出不同麦类种质的抗旱性强度依次为小黑麦、干旱半干旱圃小麦、灌溉圃小麦、合成小麦;筛选出9份优异材料,可用于今后小麦育种。  相似文献   

2.
玉米叶片水分利用效率与叶绿素a荧光参数的关系   总被引:2,自引:0,他引:2  
利用Handy PEA植物效率仪测定叶绿素a荧光参数,研究玉米自交系叶片水分利用效率(WUE)与叶绿素a荧光参数的关系。结果表明,玉米自交系叶片WUE与叶绿素a荧光参数呈极显著的正相关。其中,Fo与高水分利用效率(HWUE)玉米自交系WUE的相关系数大于低水分利用效率(LWUE)玉米自交系WUE的相关系数;最大荧光(Fm)、可变荧光(Fv)、PSⅡ原初光能转换效率(Fv/Fm)和PSⅡ潜在活性(Fv/Fo)与水分利用效率不同的玉米自交系叶片WUE的相关系数恰好相反,这是造成不同玉米自交系WUE存在差异的生理原因之一,同时也说明叶绿素a荧光参数可以作为选育HWUE玉米自交系的重要指标。  相似文献   

3.
低温胁迫及恢复对玉米光合特性的影响   总被引:1,自引:1,他引:0  
以玉米自交系掖478、合344、吉853为材料,在不同低温胁迫及恢复正常温度情况下比较幼苗光合作用及叶绿素荧光参数等指标的变化。结果表明,随着胁迫温度的下降和低温胁迫时间的延长,3个玉米自交系幼苗叶片初始荧光Fo呈上升趋势,Fv/FoFv/Fm整体上均呈下降趋势。叶绿素荧光参数随着低温胁迫程度的加强变化较大,且相同温度下的变化幅度掖478<合344<吉853。3个玉米自交系在各温度胁迫后恢复到常温时的叶片初始荧光Fo下降,Fv/FmFv/Fo整体上呈上升趋势。掖478恢复常温1~2 d后恢复到正常水平,抗冷性最强;吉853的PSⅡ系统受损较重,恢复常温3 d未达正常水平,抗冷性较弱。  相似文献   

4.
种植密度对夏玉米果穗叶生理功能衰退的影响   总被引:6,自引:1,他引:5  
以郑单958为供试品种,在大田条件下研究不同种植密度对夏玉米果穗叶生理功能衰退特性的影响。结果表明:果穗叶叶绿素a+b含量、原初光化学效率(Fv/Fm)、光系统Ⅱ(PSⅡ)潜在活性(Fv/Fo)、可溶性蛋白、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性均随果穗叶功能期的推进呈下降趋势,且随密度的增大下降趋势明显,吐丝后39d下降最显著;果穗叶叶绿素a/b、丙二醛(MDA)含量呈逐渐上升趋势。随着种植密度的增大,果穗叶光能转化和自身保护酶系活性下降,光合生产能力减弱,造成果穗叶生理功能早衰,缩短了叶片功能期。  相似文献   

5.
玉米光合生理对苗期土壤水分亏缺的响应   总被引:1,自引:0,他引:1  
在盆栽条件下研究了不同程度土壤水分亏缺下玉米苗期光合生理变化特征。结果表明:在土壤水分亏缺下,玉米叶片光合速率(Pn)、气孔导度(Gs)、蒸腾强度(Tr)均有不同程度下降,叶片水分利用效率(WUEL)有不同程度升高。轻度水分亏缺植株叶片表观光量子效率(AQY)比对照下降了6.9%,羧化效率(CE)比对照下降了26.3%,CO2补偿点(Γ)比对照升高了55.8%;重度水分亏缺处理表观光量子效率比对照下降了27.6%,玉米叶片羧化效率(CE)比对照下降了46.4%,CO2补偿点比对照升高了193.8%。土壤水分亏缺导致玉米叶片PSⅡ反应中心光化学效率(Fv/Fm)和潜在光化学效率(Fv/Fo)降低,光化学淬灭系数(qP)降低,非光化学系淬灭系数(qN)升高。轻度水分亏缺下,气孔限制是光合速率下降的主要原因;重度水分亏缺下,非气孔限制是光合速率下降的主要原因。  相似文献   

6.
为明确褪黑素对铬(Cr6+)胁迫下小麦幼苗光合和养分吸收的调节作用,在水培条件下以豫麦51(铬敏感型)和扬麦16(耐铬型)为材料,分析了Cr6+胁迫下外源褪黑素预处理(100 μmmol·L-1)后小麦幼苗光合和荧光参数及养分含量的变化。结果表明,Cr6+胁迫显著降低了小麦叶片叶绿素含量、气孔导度(Gs)和光系统 Ⅱ(PS Ⅱ)活性,导致光合速率(Pn)显著降低;Cr6+胁迫也显著减弱了根系对营养元素(N、P、K、Mg、Fe和Mn)的吸收和转运。外源褪黑素处理显著提高了Cr6+胁迫下小麦幼苗的PnGs、叶绿素(a和b)含量、实际光化学效率(ΦPSⅡ)、最大光化学效率(Fv/Fm)、光化学淬灭(qL)和电子传递能力(ETR),增加了根系和叶片营养元素的含量。综合来看,外源褪黑素会促进Cr6+胁迫下小麦幼苗对养分的吸收与转运、气孔开放、CO2传导、光能吸收和电子传递,从而缓解Cr6+对于小麦幼苗光合的抑制作用。  相似文献   

7.
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   

8.
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   

9.
为探讨水肥一体化条件下施氮量对小麦旗叶叶绿素荧光特性及籽粒产量的影响,以小麦品种济麦22为试验材料,设每公顷施纯氮0(N0)、150(N1)、180(N2)、210(N3)和240 kg(N4)五个处理,通过大田试验分析了不同处理间小麦旗叶PSⅡ 最大光化学量子效率(Fv/Fm)、PSⅡ实际光化学效率(ΦPSⅡ)、叶绿素相对含量、籽粒灌浆速率及产量的差异。结果表明,花后14~35 d,小麦旗叶Fv/Fm在N3和N4处理间无显著差异,但二处理显著高于其他处理。花后0~35 d,N3处理的旗叶ΦPSⅡ最高,施氮量再增加至N4时,ΦPSⅡ无显著变化。花后14~28 d,N3和N4处理的旗叶叶绿素相对含量显著高于其他处理;花后35 d,N3处理显著高于N4处理。粒重和灌浆速率在灌浆前期均随施氮量增加而降低;灌浆后期N3与N4处理间粒重和灌浆速率无显著差异,但二处理显著高于其他处理。籽粒产量在N3处理下最高;在施氮量增加至N4时,籽粒产量不再增加,且氮肥生产效率和氮肥农学效率分别下降了14.6%和24.0%。在本试验条件下,210 kg·hm-2是兼顾高产和高效的最佳施氮量。  相似文献   

10.
为了解水分胁迫对不同抗旱性燕麦品种光合和产量的影响,以抗旱性不同的蒙燕1号和坝莜3号为材料,在拔节期和抽穗期采用防雨棚盆栽方式,测定分析了不同水分处理[重度胁迫(30%田间持水量(FWC))、中度胁迫(45%FWC),适度控水(60%FWC)和正常供水(CK,75%FWC)]下燕麦叶片叶绿素含量、气体交换速率、叶绿素荧光动力学参数、产量及其构成因素的差异。结果表明,两个燕麦品种叶片叶绿素a含量、叶绿素b含量及叶绿素总含量、净光合速率、蒸腾速率、最大荧光、最大光化学效率(Fv/Fm)、实际光化学效率、光化学猝灭系数均随着水分胁迫程度的加剧而下降,初始荧光与非光化学淬灭系数则呈上升趋势,且水分敏感品种坝莜3号的光合受抑制程度显著大于抗旱品种蒙燕1号。燕麦的光合特性和产量受水分胁迫影响的程度整体上表现为拔节期大于抽穗期。中度和重度水分胁迫下坝莜3号的每穗小穗数、千粒重均下降,而每穗秕粒数显著增加,减产13.9%~25.7%。蒙燕1号的产量在适度控水条件下未显著下降,且水分利用效率较高,而在中度和重度水分胁迫下每穗小穗数和穗粒数均显著降低,导致减产9.1%~23.5%,但其 Fv/Fm和叶绿素a/b值较高;在相同水分条件下蒙燕1号的产量显著高于坝莜3号。这说明在水分胁迫下抗旱性强的燕麦品种的光系统Ⅱ的损伤和光抑制较轻,光合同化能力较强,产量损失少。  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.
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   

20.
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   

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