不同衰老类型小麦品种在衰老过程中光合特性的变化

以衰老类型不同的两个小麦品种鲁麦L14和935031为材料,研究了不同衰老类型小麦品种在衰老的过程中光合特性的变化。结果表明:自开花至成熟期,鲁麦L14小麦叶片光合速率、叶绿素含量、可溶性蛋白含量及光能转化效率的下降速度均明显快于小麦品种935031,但是各相关参数降低的起始时间不同,自开花后30 d鲁麦L14的叶片已经开始干枯,而935031小麦品种到成熟时大部分叶片还保持绿色,说明小麦叶片早衰与光合能力的下降有密切关系。     

不同灌溉模式对小麦‘烟农5158’光合特性及产量的影响

为了明确在胶东地区气候条件下‘烟农5158’适宜的灌溉模式,笔者在大田条件下研究了不同灌溉模式对‘烟农5158’生理特性、产量及产量三因素的影响。结果表明：随着灌溉次数的增加,‘烟农5158’旗叶相对含水量、旗叶最大光化学效率(Fv/Fm)、光合速率提高。‘烟农5158’叶片相对含水量、实际羧化效率和光合速率高于‘鲁麦21’,说明‘烟农5158’的抗旱性强于‘鲁麦21’。干旱显著降低‘烟农5158’和‘鲁麦21’的产量,‘烟农5158’的产量显著高于‘鲁麦21’。3个灌溉处理相比较,春灌2水处理（拔节水和开花水）处理的小麦产量较高。     

不同时期三个小麦主栽品种叶片光合作用的研究

不同时期三个小麦主栽品种不同层次叶片的最大光合速率均出现在盛花期以前。在灌浆期间,当前高产良种鲁麦14的光合速率下降速度较慢,比早期品种碧蚂1号和济南2号有一个较长的高光合持续期,这种差异在下部叶片表现得更为明显一些,尤其是倒3叶。从不同叶位叶片看,挑旗期参试品种均以倒2叶光合速率最高;盛花期以后,旗叶则逐渐占明显的优势。本文用叶片光合速率与叶面积的乘积,即全叶同化速率为指标,可较全面地反映不同品种叶片同化能力的大小。鲁麦14在灌装期间全叶同化速率占一定优势。叶片比叶重是鉴定筛选高光合速率个体的简单可靠的间接指标。叶片气孔阻力对光合速率有一定负效应,而叶片蒸腾对光合速率则有一定正效应。盛花期以前,叶片光合主要受气孔因素制约,而在生育后期,非气孔因素亦有很重要的作用。对小麦高产育种,尤其是光合特性的改良问题进行了讨论。     

干旱胁迫对不同小麦品种花后旗叶光合特性及产量的影响

我国小麦主产区在花后常常频发干旱,对小麦产量下降和品质产生很大影响。[目的]为筛选适于山东省旱作区栽培的优良小麦品种，在大田雨养条件下，[方法]研究了干旱胁迫对5个小麦主栽品种花后旗叶叶绿素含量、光合速率、蒸腾速率、气孔导度、胞间CO2浓度及产量变化的影响。[结果]结果表明：干旱胁迫使小麦旗叶叶绿素含量降低，济麦22和临麦6叶绿素含量相对较高。干旱胁迫使小麦旗叶光合速率降低，济麦22降低较多，青麦6降低较少。干旱胁迫下鲁麦13、青麦6能在较高的蒸腾速率下保持较高的光合速率。[结论]综合考虑，水分充足条件下济麦22适合本地区推广栽种，在干旱条件下鲁麦13和青麦6产量较稳定。     

不同土壤水分条件下棉花库源比变化对产量形成的调节效应

在新疆气候生态条件下,以不同叶型棉花品种为材料,设置不同土壤水分处理,采用人工减源疏库的方法,研究不同土壤水分条件下库源比变化对棉花产量形成的影响。结果表明,中叶型品种新陆早13号在中水(控制0～60 cm土壤相对含水量的下限为田间持水量的70%～75%)条件下,叶源轻度胁迫显著增强剩余叶片光合能力,但光合物质累积量及向生殖器官的分配率和单株结铃数、铃重均未发生明显变化,子棉产量与对照无明显差异;鸡脚叶型品种标杂A1在高水(控制0～60 cm土壤相对含水量的下限为田间持水量的85%～90%)条件下,库容轻度胁迫后叶片光合速率和光合物质累积量与对照无明显差异,但光合产物向蕾铃的分配加快,铃重增大,子棉产量有所增加;小叶型品种新陆早10号减源或疏库后子棉产量均显著低于对照。因此,依据不同类型棉花源库关系对土壤水分的响应不同,通过棉田水分管理对源库进行调节,建立合理的库源比,可进一步提高水分利用效率和棉花产量。     

干旱胁迫对不同品种小麦旗叶光合特性及产量的影响

为筛选适于山东省旱作区栽培的优良小麦品种,在大田雨养条件下,以‘冀麦5265’、‘鲁麦13’、‘济麦22’、‘临麦6号’、‘青麦6号’5个小麦品种为试验材料,利用叶绿素仪和光合仪分别测定了旗叶SPAD值及净光合速率、蒸腾速率等光合作用相关指标和产量。结果表明:干旱胁迫使小麦旗叶SPAD值降低,‘济麦22’和‘临麦6号’的SPAD值相对较高,说明叶绿素含量较高,叶片持绿性好,旗叶制造光合产物的能力强,抗旱性强。干旱胁迫使小麦旗叶光合速率降低,‘济麦22’降低较多,‘青麦6号’降低较少,‘青麦6号’抗旱性较‘济麦22’更强。干旱胁迫下‘鲁麦13’‘、青麦6号’能在较高的蒸腾速率下保持较高的光合速率。综合考虑,水分充足条件下‘冀麦5265’和‘济麦22’适合本地区推广栽种,在干旱条件下‘鲁麦13’和‘青麦6号’产量较稳定。     

减库对大豆叶片碳代谢的影响

植物的碳代谢过程与植株生长和产量形成密切相关,是受源库关系影响最明显的生理过程之一。研究减库对大豆叶片碳代谢的影响,可为明确源库关系失衡导致的减产机理研究提供理论依据。以早熟大豆品种苏豆13为材料,于2019年和2020年在江苏省农业科学院大豆试验站进行池栽试验,在大豆R4期设置减库处理(去除全部豆荚、去掉1/2豆荚和全部种子损伤处理),以正常植株为对照,研究减库对大豆碳代谢的影响。结果表明,减库处理延缓了叶片衰老和脱落,导致叶片持绿。减库处理显著抑制了短期内的净光合速率(Pn),但是未影响初始羧化速率(a)。Pn降低主要受气孔限制,随时间延长,光合抑制作用逐渐减弱并转为促进作用,在生育后期,减库处理的叶片仍能保持相对较高的a、蔗糖磷酸合成酶(SPS)、蔗糖合成酶(SuSy)和酸性转化酶(SAI)活性及光合色素、可溶性糖、淀粉、蔗糖和果糖含量,利于维持相对较高的光合性能。减库处理导致更多的光合产物向营养器官分配,茎、叶片和叶柄在一定程度上成为新的库器官,利于生育后期的叶片光合产物输出并保持相对较高的碳代谢水平。去除全部豆荚和种子损伤处理延缓叶片衰老和脱落、光合性能和碳代谢水平降低的作用...     

亏缺灌溉下小麦水分利用效率与光合产物积累运转的相关研究

在大田栽培条件下,以小麦旱地品种晋麦47和西峰20、水旱兼用型品种石家庄8号和水地品种4185为材料,分别进行0水(T0)、一水(T1)和二水灌溉(T2)处理(每次灌水量60mm),研究了光合速率、叶面积指数、干物质积累与分配、根系分布、耗水量、产量因子与水分利用效率(WUE)的关系。结果表明,在拔节前不灌溉,拔节到开花期亏缺灌溉,促进干物质积累和深根发育。随着灌溉水的增加,耗水量显著增加,产量和WUE与耗水量呈二次曲线关系。T0处理显著减少了干物质积累和成穗数,产量、经济系数(HI)和WUE最低。T1和T2产量的提高主要是增加了穗数和穗粒数。灌浆期水分亏缺降低了光合速率(Pn)和气孔导度(Gs),加速了功能叶片的衰老,但诱导了花前储存碳库的再转运,显著提高了HI和产量。因此,在拔节和开花期亏缺灌溉促进根系生长,提高了土壤水分的利用效率。而产量和产量WUE的提高主要是由于增加了灌浆期叶片的Pn和光合功能持续期,促进花前储存碳库的再转运,显著提高了HI。     

亏缺灌溉下小麦水分利用效率与光合产物积累运转的相关研究

在大田栽培条件下,以小麦旱地品种晋麦47和西峰20、水旱兼用型品种石家庄8号和水地品种4185为材料,分别进行0水（T0）、一水（T1）和二水灌溉（T2）处理（每次灌水量60 mm）,研究了光合速率、叶面积指数、干物质积累与分配、根系分布、耗水量、产量因子与水分利用效率（WUE）的关系。结果表明,在拔节前不灌溉,拔节到开花期亏缺灌溉,促进干物质积累和深根发育。随着灌溉水的增加,耗水量显著增加,产量和WUE与耗水量呈二次曲线关系。T0处理显著减少了干物质积累和成穗数,产量、经济系数（HI）和WUE最低。T1和T2产量的提高主要是增加了穗数和穗粒数。灌浆期水分亏缺降低了光合速率（P_n）和气孔导度（G_s）,加速了功能叶片的衰老,但诱导了花前储存碳库的再转运,显著提高了HI和产量。因此,在拔节和开花期亏缺灌溉促进根系生长,提高了土壤水分的利用效率。而产量和产量WUE的提高主要是由于增加了灌浆期叶片的P_n和光合功能持续期,促进花前储存碳库的再转运,显著提高了HI。     

不同穗型的两个冬小麦品种冠层结构及光合特性的研究

两个不同穗型的冬小麦品种： 多穗型品种济南16和大穗型品种鲁麦22, 在冠层 结构、 光合特性、 干物质积累运转等方面存在较大的差异, 济南16上部节间相对较长 , 株高构成指数I值较大。 鲁麦22上三叶面积、 长宽比、 夹角较小。 济南16冠层 光截获大于鲁麦22, 而鲁麦 22 下层相对光强较大。 生育期内小麦群体光合速率的变     

穗分化期外施24-表油菜素内酯(EBR)促进水稻源、库及籽粒灌浆的生理机制

水稻产量高低与其籽粒灌浆能力的强弱密切相关, 而籽粒灌浆能力的强弱受源和库的影响。已有研究表明, 油菜素甾醇类化合物(brassinosteroids, BRs)对水稻生长发育和产量具有正向调节作用。为进一步阐明BRs调控水稻源强、库容和库活性的生理机制及其相互关系, 本研究在大田条件下, 以粳稻日本晴为试验材料, 在穗分化期喷施24-表油菜素内酯(24-epibrassinolid, EBR), 分析其相关影响。首先, 两种不同浓度的EBR处理通过促进光合产物的合成及其在灌浆过程中的转运提高了水稻的源强。其次, 两种浓度EBR处理均增大了水稻的库容, 但两种处理的影响方式存在差异, 低浓度处理(T1) 显著提高水稻籽粒的千粒重, 对穗粒数的影响较小; 高浓度处理(T2)则显著增加单位面积的穗数和穗粒数, 对千粒重的影响较小。再次, 两处理同时提高了水稻强、弱势粒的蔗糖裂解酶活性, 尤其对弱势粒酸性转化酶(acid invertase, AI)活性的影响较大, 有助于光合产物向弱势粒分配, 进而促进弱势粒淀粉合成和籽粒灌浆, 提高其充实度和结实率。最后, 两处理均显著增加了水稻的产量, T1和T2分别平均增加5.6%和15.2%, T2比T1平均增产9.1%。因此, 与低浓度EBR处理下的千粒重增大相比, 高浓度处理下穗粒数的增加对产量影响更大。综上所述, 穗分化期进行EBR处理能够增大水稻的源强、库容和库活性, 进而促进光合物质的积累和分配, 有利于籽粒灌浆; 在光合物质供应充足和库活性显著提高的基础上, 库容的增大有助于产量的明显提高。     

小麦籽粒发育过程中激素含量变化

两个冬小麦品种的强势籽粒和弱势籽粒的灌浆特点不同,鲁215953表现为弱势粒灌浆速率高值持续期短,而鲁麦14表现为弱势粒灌浆速率低。籽粒发育过程中,IAA, iPA含量变化为双峰曲线,ABA为单峰曲线,而GA含量变化因品种而异。弱势粒内IAA, GA与iPA水平低,iPA含量第一峰出现早,籽粒灌浆高峰之前的ABA含量低,并且其ABA含量升     

14C-labelled Assimilate Distribution in Flowering Maize Plants

Maize ( Zea mays L.) plants were grown in the field and labelled with ¹⁴CO₂ at four leaf positions from silking up to maturity. The ear leaf was the most important source of labelled photosynthates to the ear, followed by the first leaf blade above and below the ear. The movement of labelled assimilates from the second leaf blade below the ear was predominantly downwards. The ear became an important sink soon after silking and continued in importance till harvest.
Initially assimilates were partitioned within the ear as husk < cob < grains but at harvest as grains < cob < husk. There was considerable remobilization of assimilates from the husk and stem. Removal of leaves drastically altered the pattern of distribution of labelled photosynthates and the direction of movement was determined by the position of the source leaf blade and the defoliation treatment. Darkening the leaf blades did not much alter the translocation of the labelled photosynthate and increased slightly its proportion to the grains. The removal of the ear severely altered the pattern of distribution of ¹⁴C, which was mostly deposited in the stem.     

Allocation of Photosynthates and Grain Growth of Two Wheat Cultivars with Different Potential Grain Growth in Response to Pre- and Post-anthesis Shading

Grain yield in wheat is dependent on photosynthate production and allocation. Light intensity is one of the main factors affecting photosynthate production and allocation, and grain yield. This study was conducted to determine whether cultivars varying in grain number per spike and grain weight respond differently to pre‐anthesis shading (PRE) and post‐anthesis shading (POST), and to characterize the responses in production and allocation of photosynthate, yield and yield components, and spike traits. Both PRE and POST caused a decrease in both dry matter (DM) accumulation and allocation to grain. Cultivar Lumai 22, which has a large spike and large grains, was more sensitive to either PRE or POST. PRE reduced photosynthate production and partitioning to the spike in Lumai 22 at anthesis. In contrast, PRE had little influence on these parameters in the small‐spike, small‐grain cultivar Yannong 15. POST reduced the partitioning to the grain, especially in Lumai 22, for which marked reductions in biomass and grain yield were found for both the PRE and POST treatments. Changes in yield components attributable to shading varied with cultivars. The number of spikes m^?2 was not affected by either PRE or POST. Lumai 22 was more seriously affected by shading than Yannong 15 in terms of grain number per spike and weight per grain. The decreases in grain number or weight per spikelet in both the PRE and POST treatments took place mainly in the upper and basal spikelets, especially in Lumai 22. We concluded that the adaptability of the small‐spike, small‐grain cultivar Yannong 15 to either PRE or POST was much greater than that of the large‐spike, large‐grain cultivar Lumai 22 in terms of many characteristics closely related to grain yield. Hence, we suggest that, in areas where low light intensity often occurs, the small‐spike, small‐grain cultivar would be more likely to produce high, stable grain yields.     

不同生育时期施氮对冬小麦氮素分配及叶片代谢的影响

通过＾１５Ｎ示踪结合叶片代谢变化研究二棱期,雌雄蕊原基形成期和四分体期分别施氮对冬小麦籽粒产量和蛋白质含量的影响机理。结果表明：四分体形成期和雌雄蕊原基形成期施氮处理,收获期营养器官中＾１５Ｎ原子百分超显著降低,籽粒中＾１５Ｎ原子百分超明显增加,并提高了开花后叶片硝酸还原酶活性和叶片衰老后期的光合作用速率,显著增加了籽粒产量和籽粒蛋白质含量。     

旱作和灌溉条件下小麦籽粒淀粉粒粒度的分布特征

在灌溉和旱作2种栽培条件下, 以籽粒淀粉含量不同的小麦品种鲁麦21和德99-3为试验材料, 研究了籽粒淀粉粒的分布特征及基因型差异。结果表明, 与灌溉栽培相比, 旱作栽培条件下2个小麦品种籽粒B型淀粉粒(2.0~9.8 mm和<9.8 mm)的体积、表面积百分比显著增加, 而粒径>18.8 mm的A型淀粉粒的体积、表面积百分比明显减少。水分亏缺降低了2个品种的籽粒直链淀粉和总淀粉含量, 而增加了籽粒蛋白质含量、峰值黏度和最终黏度, 这表明旱作栽培有利于小麦籽粒品质的改善。相关分析表明, 2个品种籽粒的直链淀粉和总淀粉含量均与2.0~9.8 μm和<9.8 mm的淀粉粒体积百分比呈负相关, 与9.8~18.8 mm的淀粉粒体积百分比呈正相关, 籽粒蛋白质含量与2.0~9.8 mm和<9.8 mm的淀粉粒呈显著和极显著正相关, 而与9.8~18.8 mm的淀粉粒呈负相关。表明小淀粉粒(2.0~9.8 mm和<9.8 mm)的直链淀粉和总淀粉含量较低、蛋白质含量较高, 而大淀粉粒(9.8~18.8 mm和>9.8 mm)具有较高的直链淀粉和总淀粉含量。     

小麦开花后源库关系分析

小麦开花后的源库关系分析结果表明，库容量的大小影响开花后光合产物的生产和分配，较大的库容可以促进叶片光合潜力的发挥和光合产物向穗部的运转。开花后绿叶面积的大小和光合强度的高低影响籽粒的灌浆速率，粒重受花后干物质积累量的制约。说明小麦开花后库对源有反馈调节作用，而源又影响库的充实，源库关系在动态变化中相互协调取得平衡。栽培措施应使源库关系在高水平上取得动态平衡，才能获得高产，粒叶比既反映了库容的相对     

Yield Formation in Mediterranean durum wheats under two contrasting water regimes based on path-coefficient analysis

The components of grain yield are altered by adverse growing conditions as the effects of certain environmental factors on crop growth and yield differ depending upon the developmental stages when these conditions occur. Path-coefficient analysis was used to investigate the main processes influencing grain yield and its formation under Mediterranean conditions. Twenty-five durum wheat genotypes, consisting of four Spanish commercial varieties and 21 inbred lines from the ICARDA durum wheat breeding program, were grown during 1997 and 1998 under both rainfed and irrigated conditions in southern Spain. {P}ath-coefficient analysis revealed that under favourable conditions grain yield depended in equal proportion on the three primary yield components (i.e. spikes m⁻², grains spike⁻¹, and mean grain weight), whereas in the rainfed experiments, variations in grain yield were due mainly to spikes m⁻² and to a lesser extent to grains spike⁻¹. Compensatory effects were almost absent under irrigated treatments; however, under water shortage, spikes m⁻² exerted a negative influence on grain spike⁻¹ due mainly to a negative interrelationship between tiller production and apical development. These compensatory effects could partially explain the restricted success in durum wheat breeding observed in water-limited environments of the Mediterranean region. Under rainfed conditions the number of spikes m⁻² depended mainly on the ability for tiller production, whereas in the irrigated experiments the final number of spikes was determined mostly by tiller survival.     

施肥对旱作冬小麦植株水分变化与光合生理特性的影响

研究表明，中等以上肥力的冬小麦水浇地改为旱作时，通过合理施用有机肥和氮素化肥，可使土壤保持较高的含水量。随着有机肥用量的增加，植株叶片气孔导度变小，蒸腾速率与光合速率下降，叶片保水能力增强，提高了小麦植株的光合作用效率。与施用化肥相比，有机肥在降低植株叶片相对含水量、脱水速率方面作用显著。这些生理特性的改善，导致小麦产量提高１１％，从而达到充分利用当地自然降水，节约地下水，降低生产成本，获得与水浇