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1.
《Plant Production Science》2013,16(3):285-292
Abstract

Effects of nitrogen (N) deficiency on photosynthetic gas exchange and photosystem II (PSII) photochemistry of flag leaves during grain-filling stage were investigated in six rice cultivars, Kasalath (a conventional indica), IR36 (an improved indica), Shirobeniya (a conventional japonica), Nipponbare (an improved japonica), Akenohoshi (an improved japonica-indica intermediate type) and BSI429 (an improved tropical japonica, a new plant type line) grown hydroponically in N-sufficient (NS) and N-deficient (ND) solution. From 3 to 24 days after heading (DAH), net photosynthetic rate (Pn), maximum quantum yield of photosystem II (PSII) (Fv/Fm), quantum yield of PSII electron transport ( Φpsii), and contents of chlorophyll (Chl) and ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) in the flag leaves decreased, particularly under the ND condition in all six cultivars. A substantial difference was observed among the ND plants for the sustainability index (SI, the ratio of the value at 24 DAH to that at 3 DAH) of Pn, Fv/Fm, Φpsii, Chl content and Rubisco content; SIs of those parameters of Akenohoshi, BSI429, Nipponbare and Shirobeniya were higher than those of IR36 and Kasalath. The SI of Pn showed significant positive correlations with those of Fv/Fm, Φpsii, and the contents of Chl and Rubisco under the ND condition. It was concluded that the sustainability of photosynthesis in the flag leaves was mainly due to those of PSII photochemistry and electron transport, which was associated with the maintenance of Chl and Rubisco under the ND condition.  相似文献   

2.
Abstract

The objective of this study was to establish the correlation of the chlorophyll meter (SPAD) readings with the contents of chlorophyll (Chl) and ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), the gross photosynthetic rate (Pg), and the maximum quantum yield of photosystem II (PSII) (Fv/Fm) in flag leaves of rice (Oryza sativa L.) in ripening stage. The SPAD readings significantly correlated with the Chl content, the Rubisco content, Pg and Fv/Fm (R2 = 0.848, 0.648, 0.671 and 0.712, respectively), which suggests that the SPAD meter has the potential to estimate the photosynthetic capacity of the flag leaves. However, both Pg and Fv/Fm had a stronger relationship with the Rubisco content than the SPAD readings, indicating that the PSII photochemical and CO2 assimilation capacities are strongly influenced by the Rubisco content. Therefore, accurate calibration would be indispensable to obtain the physiological information from the SPAD readings of flag leaves.  相似文献   

3.
Summary The slow kinetics of chlorophyll fluorescence were examined in seven potato genotypes grown either fully irrigated or droughted from the time of plant emergence. Constant and variable fluorescence (F o andF v respectively) declined with time in plants from both irrigated and droughted treatments, but the decline was greater in droughted than irrigated plants. However, the yield of variable fluorescence (F v/(F o+F v)) was unaffected by the drought treatment. The main effect of drought was upon the quenching of variable fluorescence. Both the half life of the decay of variable fluorescence (q1/2) and the secondary maximum (M) were significantly greater in the droughted plants than in those from the irrigated treatment. Significant differences between genotypes were found forF v/(F o+F v),M andq 1/2. Genotype-by-treatment interactions were non-significant for all the variables examined. Changes in chlorophyll fluorescence transients were not closely related to changes in leaf water potential.  相似文献   

4.
不同基因型玉米自交系苗期干旱-复水的生理响应机制   总被引:4,自引:1,他引:3  
采用称重控水法模拟干旱胁迫,设对照和胁迫两个处理,在3叶期对24个玉米自交系叶片相对含水量(RWC)、游离脯氨酸(Pro)等生理指标进行测定,研究玉米的抗旱机理及复水补偿效应机制。结果表明,干旱胁迫下玉米叶片相对含水量、叶绿素荧光参数(F_v/F_m)和叶绿素含量(Chl)与对照相比显著下降,游离脯氨酸(Pro)、超氧化物歧化酶(SOD)和氧化物酶(POD)明显上升,复水后不同基因型自交系各生理指标表现出不同程度的补偿效应。利用隶属函数法将D17982、郑H71、PH4CV、昌7-2和L269等14份自交系归为抗旱性较强的自交系,PH4CV、HCL645、D17982、郑7314、郑H71和郑9712这6份自交系归为复水恢复能力强的自交系。  相似文献   

5.
References

The aim of this investigation was to comparatively examine the physio-biochemical responses of oil palm seedlings to mannitol- and PEG-induced iso-osmotic stresses. The water content of osmotically stressed oil palm seedlings decreased, but the proline content and the electrolyte leakage of the seedlings increased with decreasing water potential (Ψw). However, the responses varied with the strength of osmotic stress and type of osmotic agent. Relative electrolyte leakage (REL) was negatively correlated to chlorophyll content in the osmotically stressed leaves. Chlorophyll a (Chla), chlorophyll b (Chlb), total carotenoids (Cx+c) and total chlorophyll (TC) in the seedlings were significantly reduced by osmotic stress, subsequently reducing maximum quantum yield of PSII (Fv/Fm) and photon yield of PSII (Φpsii), thereby lowering net-photosynthetic rate (Pn) and inhibiting growth. Physio-biochemical parameters, including REL, Fv/Fm, and Φpsii in oil palm seedlings were reduced more greatly by PEG-induced osmotic stress than by mannitol-induced stress. A deterioration in morphological characters, including leaf chlorosis, leaf burn, and green leaf area reduction were demonstrated in oil palm seedlings under osmotic stress induced by either mannitol or PEG. However, the toxic symptoms in oil palm seedlings under PEG-induced stress were severer than in those under mannitol-induced iso-osmotic stress, especially under severe osmotic stress.  相似文献   

6.
以郑单958幼苗为试验材料,设置空白对照(CK)、正常水分条件下1 mmol/L丙三醇(Gly)处理玉米幼苗叶片、20%聚乙二醇(PEG-6000)模拟干旱胁迫(PEG)、20%聚乙二醇模拟干旱胁迫+1 mmol/L丙三醇(PEG+Gly)处理玉米幼苗叶片4个处理展开试验。结果表明,干旱胁迫下外源施用1 mmol/L丙三醇能显著提高叶片超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)活性;丙二醛(MDA)和过氧化氢(H2O2)积累减少;最大光量子效率(Fv/Fm)和光系统Ⅱ潜在活性(Fv/Fo)显著提高,玉米幼苗叶片的净光合速率(Pn)、气孔导度(Gs)和蒸腾速率(Tr)、相对含水率及生长指标均显著提高,胞间CO2浓度(Ci)降低。因此,外源施用丙三醇能通过降低叶片的氧化损伤和提高细胞保水能力来改善...  相似文献   

7.
小麦品种郑麦7698耐强光高温的生理机制   总被引:1,自引:0,他引:1  
为了阐明小麦品种郑麦7698耐强光高温的生理机制,以黄淮南片麦区区域试验对照品种周麦18和大面积推广品种矮抗58为对照,研究了该试验材料在强光、高温、强光高温交叉胁迫下的生理特性。结果表明,3种逆境对小麦叶片光合功能的影响程度依次为强光高温强光高温,且3个品种的耐强光高温特性存在显著差异。3种逆境胁迫处理下,郑麦7698的光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)、PSⅡ最大光化学效率(Fv/Fm)、光化学猝灭(qP)的下降幅度均显著低于周麦18和矮抗58,相对电导率、丙二醛(MDA)含量、超氧阴离子生成速率、过氧化氢含量的上升幅度显著小于周麦18和矮抗58,超氧化物歧化酶、过氧化物酶和过氧化氢酶活性在逆境下的上升幅度显著高于周麦18和矮抗58,表现出较好的耐强光高温特性。综合分析表明,郑麦7698之所以较周麦18和矮抗58具有更好的耐强光高温特性,是因为其在逆境下具有较高水平的抗氧化酶活性,可有效清除活性氧类物质,降低其光合机构受损程度,从而维持较高水平的光合效率。  相似文献   

8.
为了解小麦叶片衰老与缺氮诱导及碳氮平衡之间的关系,以两个缺氮衰老响应敏感品种(周麦24和运旱618)和两个缺氮衰老响应不敏感小麦品种(衡观35和西农979)为材料,分析了小麦苗期低氮诱导下表征叶片衰老的叶绿素含量、F_v/F_m、净光合速率,以及表征碳氮平衡的全氮和非结构性碳水化合物(可溶性糖、淀粉)比值。结果表明,低氮胁迫后,4个小麦品种叶片的净光合速率、叶绿素含量和F_v/F_m显著降低,说明低氮诱导和加速了小麦叶片的衰老,而缺氮衰老响应敏感品种的衰老程度显著高于不敏感品种。缺氮衰老响应敏感和不敏感小麦品种叶片氮含量在低氮胁迫后均显著降低,同时碳累积量(可溶性糖和淀粉含量)均显著升高。进一步分析表明,缺氮诱导的小麦叶片衰老可能并非受独立的氮缺乏和碳累积调控,而可能与碳氮平衡(碳氮比例)有关,即碳氮平衡可能参与了低氮诱导的叶片衰老调控,而缺氮下耐衰老品种的叶片维持碳氮代谢平衡的能力较强。  相似文献   

9.
《Plant Production Science》2013,16(3):284-294
Abstract

The agronomic and physiological effects of waterlogging in winter wheat were examined at four growth stages in the 2011/2012 and 2012/2013 seasons. In both seasons, the greatest yield penalties occurred by waterlogging at the tillering stage (10%–15% decrease), followed by the jointing stage; however, waterlogging at the grain filling stage had less effect on the yield. The lower grain yield caused by waterlogging at the tillering stage was primarily reflected in reductions in spike and grain numbers per m2. Waterlogging at the jointing and booting stages reduced grain weight through reduced dry matter translocation. In addition, waterlogging at the tillering stage significantly reduced chlorophyll content and thus photosynthetic capacity, resulting in a lower Fv /Fm ratio, apparent electron transport rate (ETR), effective quantum yield of photosystem II (ΦPSII) and photochemical quenching (qP). However, waterlogging at the grain filling stage improved the leaf photosynthetic capacity and grain yield. We found that the tillering stage was most the susceptible to waterlogging in wheat; therefore, the maintenance of photosynthetic performance after anthesis could be a reasonable strategy for increasing grain yield.  相似文献   

10.
以紧凑型玉米品种先玉335为试验材料,叶面喷施混合肥(NPK)、磷钾肥(PK)、氮肥(N),以喷施清水(CK)为对照,研究不同生育时期叶面肥对其光合特性及产量的影响。结果表明:不同叶面肥处理对玉米叶面积、叶绿素含量(Chl)、光合速率(Pn)、气孔导度(Gs)、胞间CO2浓度(Ci)、蒸腾强度(Tr)均有不同程度的影响,因生育时期而不同;叶面肥处理后产量均高于对照,以混合肥处理产量增加最多,磷钾肥处理次之,氮肥处理增幅最小。  相似文献   

11.
水分胁迫及复水对玉米光合速率及可溶性糖的影响   总被引:9,自引:0,他引:9  
采用聚乙二醇(PEG-6000)模拟不同程度的干旱胁迫,研究了不同水分胁迫处理及复水对玉米光合速率和叶片可溶性糖浓度的影响。结果表明,水分胁迫使净光合速率(Pn)下降,叶片可溶性糖浓度升高,且与胁迫程度呈正相关。复水后,轻度胁迫处理的玉米光合速率恢复较快并超过对照,可溶性糖浓度降低但仍然高于对照;重度胁迫处理的光合速率在复水后较长时间内低于对照,可溶性糖的浓度高于对照及轻度胁迫处理。叶片可溶性糖浓度与光合速率之间具有显著的负相关关系。  相似文献   

12.
为了解植物光合机构及抗氧化酶系统对高光、水分及盐胁迫的适应机制,比较分析了光强1 800 μmol·m-2·s-1、20% 聚乙二醇(PEG-6000)和0.3 mol·L-1 NaCl处理下小麦叶绿素荧光以及抗氧化酶活性的变化。结果表明,与对照相比,高光胁迫、水分胁迫和盐胁迫下小麦叶片相对含水量、总蛋白含量以及叶绿素含量均下降,以水分胁迫效应最显著,盐胁迫次之。三种胁迫均显著降低了小麦叶片的光合速率、气孔导度、蒸腾速率、PSII最大光化学效率(Fv/Fm)及电子传递率(ETR),而显著增加胞间CO2浓度、非光化学淬灭(NPQ)、脯氨酸及可溶性糖含量,也以水分胁迫效应最显著。三种胁迫下小麦叶片内的超氧化物歧化酶(SOD)、过氧化物酶(POD)及过氧化氢酶(CAT)活性随胁迫时间的延长呈现不同的变化趋势。其中,SOD活性在三种胁迫下均呈先升后降的趋势;POD活性在高光和水分胁迫下先升后降,而在盐胁迫下呈上升趋势;CAT活性在高光和盐胁迫下呈上升趋势,而在水分胁迫下呈下降趋势。以上结果表明,在三种环境胁迫中,水分胁迫给小麦带来的伤害最严重,盐胁迫次之,高光胁迫最轻。 此外,小麦抗氧化酶系统在高光胁迫、水分胁迫及盐胁迫下应答机制不同。  相似文献   

13.
为了研究披碱草属种间杂种抗旱性优势的遗传机理,以加拿大披碱草(J1)、老芒麦(L1)及其种间杂种F1为试验材料,经干旱胁迫处理,采用甲基化敏感扩增多态性(MSAP)方法,探究干旱胁迫后亲本及种间杂种F1的DNA甲基化变化规律。结果表明,亲本材料L1和J1的DNA平均甲基化水平分别为45.41%和59.53%,杂种F1的DNA甲基化水平为44.24%,说明杂种在形成过程中发生了DNA去甲基化作用。全甲基化在杂交种的DNA甲基化模式中占主导地位。干旱胁迫前亲本L1、J1和杂种F1的DNA甲基化程度分别为32.73%、41.54%和28.00%,杂种F1甲基化水平为亲本材料的75.40%;干旱胁迫后各材料的DNA甲基化程度均增加,平均增幅分别为14.99、20.44和19.78个百分点,说明干旱胁迫对不同材料DNA甲基化水平均有明显影响,且具有特异性。杂种F1的抗旱性最强,其DNA甲基化水平低于亲本,说明杂交种的抗旱性与DNA甲基化水平存在一定的负相关。  相似文献   

14.
尿素对骠马胁迫紫苏幼苗的缓解效应   总被引:1,自引:0,他引:1  
为探讨尿素对骠马胁迫紫苏幼苗的缓解效应,阐明适宜紫苏生长的最佳除草施肥条件。采用随机区组试验设计,在紫苏六叶期喷施不同浓度的尿素(0、1、2、4和8g/L)和6.9 %骠马水乳剂(0、1.33、2.66、5.32和 7.98 mL/L),分析其对紫苏光合特性指标、荧光特性、杂草防效和籽粒产量的影响。结果表明,骠马显著降低紫苏叶片的叶绿素含量指数(CCI),净光合速率(Pn)和气孔导度(Gs)也均不同程度降低,胞间CO2浓度(Ci)升高,说明骠马显著抑制紫苏的光合特性,且表现出一定的剂量-效应关系;叶绿素荧光分析表明,除草剂显著降低了PSⅡ最大光化学效率(Fv/Fm)、PSⅡ潜在活性(Fv/Fo)、PSⅡ实际光化学效率(ФPSⅡ)及光化学荧光淬灭系数(qP),非光化学淬灭系数(NPQ)则呈一定的上升趋势。表明在除草剂骠马胁迫下紫苏叶片发生了光抑制,PSⅡ复合体受到损伤伴随着光合电子传递受阻;8 g/L的尿素处理效果相同;而1~4g/L浓度的尿素处理则效果相反。1~4 g/L的尿素和不同浓度的骠马先后处理,比单用骠马处理效果好,A组的P1N3处理可使籽粒产量比单独施用骠马增产11%,杂草防效提高11.35%,表明先施4 g/L的尿素再施1.33 mL/L 的骠马,能显著缓解骠马对紫苏的胁迫,提高其光合性能,并使其光系统Ⅱ维持较高的光化学效率,该施药模式具有平衡除草施肥技术,安全高产等特点,有较高的推广价值。  相似文献   

15.
Henna (Lawsonia inermis L.) is naturally cultivated from north-east Africa to India as a medicinal-industrial plant. The objective of this study was to evaluate the possible role of salicylic acid (SA) for mitigating the salinity stress. For this purpose, we evaluated the effect of three concentrations of SA (0, 40 and 80 μM) and salinity (0, ?3 and ?6 bar) on photosynthetic pigments, protein content, catalase (CAT, EC 1.11.1.6) activity, electrolyte leakage and leaf relative water content (RWC). The experiment was carried out with a factorial arrangement based on complete randomized design in triplicates at University of Kerman, Iran. The results revealed that salinity caused a significant decrease in photosynthetic pigments, protein content, RWC and quantum yield of henna. By increase in salinity levels from 0 to ?6 bar, the mean values of mentioned traits were reduced. CAT activity, electrolyte leakage, F0 and Fm were elevated significantly with increasing the salinity concentration. Application of SA under salinity stress increased the photosynthetic pigments, protein content, CAT activity, leaf RWCs and quantum yield, while it decreased electrolyte leakage, F0 and Fm. It can be concluded that SA alleviated the stress generated by NaCl possibly through the ameliorated antioxidant defense system.  相似文献   

16.
Near isogenic lines carrying large-effect QTL (qtl12.1), which has a consistent influence on grain yield under upland drought stress conditions in a wide range of environments, were evaluated under water stress in the fields. The line which gave higher yield under drought was crossed with a local elite line, PMK3, and forwarded to F2:3 generation. Significant variation was found among the F2:3 lines for agronomic traits under water stress in the fields. Low to high broad sense heritability (H) for investigated traits was also found. Water stress indicators such as leaf rolling and leaf drying were negatively correlated with plant height, biomass and grain yield under stress. Bulked segregant analysis (BSA) was performed with the markers in the vicinity of qtl12.1, and RM27933 was found to be segregated perfectly well in individual components of drought resistant and drought susceptible bulks which were bulked based on yield under water stress among F2:3 lines. Hence, this simple and breeder friendly marker, RM27933, may be useful as a potentially valuable candidate marker for the transfer of the QTL qtl12.1 in the regional breeding program. Bioinformatic analysis of the DNA sequence of the qtl12.1 region was also done to identify and analyze positional candidate genes associated with this QTL and to ascertain the putative molecular basis of qtl12.1.  相似文献   

17.
为给冬小麦节水高产栽培提供理论依据,采用盆栽试验,研究了不同土壤肥力下返青后干旱及拔节期复水对冬小麦光合特性和水分利用效率的影响。结果表明,同一土壤水分条件下,光合速率、蒸腾速率、气孔导度、胞间CO2浓度均随土壤肥力的降低而降低;同一土壤肥力下,光合速率、蒸腾速率、气孔导度、胞间CO2浓度均随干旱程度的增加而降低。干旱胁迫复水24 h后,光合速率、蒸腾速率、气孔导度、胞间CO2浓度均出现了补偿或超补偿效应,但中度干旱恢复度大于重度干旱。光合速率以HA处理(高肥力、最大田间持水量的85%)最高,单叶水分利用效率在干旱胁迫下和复水24 h后均以HB处理(高肥力、最大田间持水量的55%)最高。以上结果说明,冬小麦返青期中度干旱条件下,高肥力土壤有利于复水后光合系统恢复和单叶水分利用效率提高,而重度干旱下贫瘠土壤应减少基肥的施入量。  相似文献   

18.
为明确冬前镇压和灌溉对冬小麦灌浆期旗叶功能的影响,以济麦22为材料,在2016-2017小麦生长季,对其进行冬前镇压+灌溉(C+I)、灌溉(I)和镇压(C)处理,以常规种植管理为对照(CK),研究不同冬前栽培措施对冬小麦灌浆期土壤微环境、旗叶光合特性和叶绿体超微结构以及最终产量和生物量的影响。结果表明,与CK相比,C、I及C+I处理都可提高麦田土壤含水量和土壤温度,可增加花后14~28d旗叶叶绿素相对含量(SPAD)、灌浆期旗叶最大光学效率(Fv/Fm)、净光合速率(Pn)和蒸腾速率(Tr),缓解旗叶SPAD、Fv/Fm、Pn和Tr在灌浆后期的下降,其中以C+I处理的效果最佳;灌浆中后期(花后21d),CK条件下小麦植株旗叶部分叶绿体呈圆形,大部分基粒片层变形且排列紊乱,可见较多的亲锇颗粒,但C+I、C和I处理下叶绿体的破坏程度降低,较多的叶绿体呈椭圆形,单位面积内叶绿体数和叶绿体基粒数提高,基粒片层较CK清晰且排列紧密,亲锇颗粒数量减少,其中C+I和I处理对叶绿体超微结构的改善作用大于C处理。这说明在本试验条件下,冬前镇压+灌溉较单独灌溉或镇压更有利于改善小麦灌浆期旗叶光合功能,缓解灌浆后期旗叶的衰老,促进小麦产量形成。  相似文献   

19.
《Plant Production Science》2013,16(3):155-159
Summary

A greenhouse experiment was conducted to compare root system development of two upland rice cultivars, IRAT 13 and Senshou, during recovery from drought stress and to identify the plant traits that confer drought resistance. From 62 days after sowing (62 DAS), drought stress was given for 6 d followed by rewatering for 14 d. Root length density (RLD) and root diameter (thickness) were measured at the end of the stress and rewatering periods. Control plants were well-watered throughout the study. Gultivar IRAT 13 had thicker roots and higher relative RLD (ratio of RLD in drought-stressed plants to that in control plants) than under drought stress, and significantly higher root growth recovery after rewatering cultivar Senshou. Related plant traits such as evapotranspiration (ET), leaf and stem dry weights and weight of senescent leaves (dead leaves) in IRAT 13 were significantly more favorable for drought resistance compared to Senshou.  相似文献   

20.
BS型小麦光温敏雄性不育系光合特性研究   总被引:1,自引:0,他引:1  
为了解BS型小麦光温敏雄性不育系光合特性的差异,分析其光合特性的影响因子,以指导高光效不育系的选育,以6份BS型小麦光温敏不育系和常规品种京411为研究材料,于北京顺义(不育系繁殖区)和河南南阳(不育系制种区)分期播种,分析不同材料在抽穗期、开花期和花后30 d的净光合速率(P_n)、气孔导度(G_s)、胞间CO_2浓度(C_i)、蒸腾速率(T_r)、叶绿素荧光参数(F_v/F_m)等光合特性指标的差异,以及不同区域不育系的P_n、T_r和结实率与播期、旗叶面积及株高的相关性。结果表明,不育系的P_n、G_s、T_r和F_v/F_m变化趋势均为抽穗期或开花期达到最高值,花后30 d降为最低值,而C_i的变化趋势为花后30 d达到最高值。P_n和T_r较高的材料为BS485,G_s和T_r较高的材料为BS366;P_n较低的材料为BS93,T_r较低的材料为BS1453和BS210。在北京顺义,P_n与结实率、G_s、T_r和F_v/F_m呈正相关,与旗叶面积呈负相关;T_r与播期、P_n和G_s呈正相关,与株高和F_v/F_m呈负相关;结实率与P_n呈正相关,与旗叶面积呈负相关。对P_n影响最主要的因子是播期和T_r,其次是结实率、F_v/F_m、G_s和旗叶面积;对T_r影响最主要的因子是播期、G_s和P_n,其次是株高和F_v/F_m;对结实率影响最主要的因子是P_n,其次是G_s和旗叶面积。在河南南阳,P_n和结实率与各因子相关性均不显著;T_r与播期和G_s呈正相关,与C_i呈负相关;对T_r影响最主要的因子是播期和G_s,其次是C_i。  相似文献   

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