在不同海拔地区种植的红波罗花对水分的响应

比较了高山花卉红波罗花(Incarvillea delavayi)在原产地香格里拉和引种栽培地昆明的光合作用和叶片性状对水分的响应差异.结果表明:在两个实验点光合速率(Pn)均随着土壤水分的减少而下降.移栽昆明后,在同样的水分条件下与香格里拉相比其光合速率(Pn)较低,叶绿素含量和Chl a/b的比值则没有显著变化,但单位面积的叶片氮含量(LNC.)有所增加.红波罗花在昆明较低的光合速率(Pn)与较低的气孔导度(g)和叶肉导度(gn)以及叶氮向光合机构中分配(PB、PB)减少有关.另外,移栽昆明后,当供给的水分高于土壤田间持水量的40%时,红波罗花能够正常生长,且对水分供应的响应不如在香格里拉的植株敏感,表现在当土壤的含水量为田间最大持水量的40%-85%时,光合速率、比叶重(LMA)、叶绿素含量、LNC均比较稳定,且不同的水分处理间没有显著性差异.除此之外,红波罗花在昆明的生长存在一个水分阈值(土壤田问持水量的40%),当供给的水分低于这个阈值时,相对生长速率出现负增长.研究结果暗示红波罗花能够在较低海拔地区引种栽培.     

杂交马褂木叶片发育过程中资源利用效率的变化格局

对一年生杂交马褂木( Liriodendron chinense Sarg.× L. tulipifera L.)叶片展开过程中光能转换效率、水分利用效率和光合碳同化的变化规律及栽植密度对中下部叶片资源利用效率的影响进行了研究,结果表明(1) 叶片展开过程中,净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(E)、气孔限制值(Ls)、总光合速率(Pm)、净光合比率(Pn/Pm)、PSⅡ的原初光能转化效率(Fv/Fm)和PSⅡ的光量子产率(φPSⅡ) 、羧化效率(CE) 和水分利用效率(WUE)显著上升,而胞间CO2浓度(Ci)和呼吸速率(R)显著下降;(2) 叶片展开过程中,光合碳同化"暗系统"的完善远远慢于能量转换的"光系统";(3) 叶片展开过程中,影响净光合速率增长的主导因素不是气孔导度,而是"暗系统"完善程度, "光系统"的影响远小于"暗系统"的影响; (4) 郁闭的高密度群体中,中下部叶片的Pn、Gs、E、Ls、Pm、Fv/Fm、φPSⅡ、CE和WUE显著低于上部完全展开叶,Ci显著高于上部完全展开叶,Pn/Pm和上部完全展开叶没有显著差异,而未郁闭的低密度群体中,中下部叶片的上述所有参数与上部完全展开叶无显著差异;(5) 导致高密度群体叶片Pn大幅度下降的主导因素是CE的大幅下降,而不是"光系统"和气孔导度;(6) 密度过大加速了中下部叶片光合功能的下降.     

遮荫和全光下生长的棉花光合作用和叶绿素荧光特征

 遮荫条件下（遮荫下光强相当于自然光强的40％左右）棉花(Gossypium hirsutum)叶片光合速率明显降低,仅为自然光强下生长叶片的30%～40％,叶片中RuBP羧化酶活性降低,而表观量子效率(AQY)较高。不同光照条件下生长的棉花叶片对短时间持续光强的光合诱导过程有明显的差异,由弱光转到强光下,自然光强下生长的叶片的Pn、Gs、ΦPSⅡ及非光化学猝灭系数(NPQ)都能在较短的时间内达到最大值,而遮荫叶片需要的时间较长;遮荫下生长的棉花叶片的实际光化学效率,随光强的增加下降幅度较大,而自然光照下生长的叶片下降幅度较小;自然光照下生长的叶片的NPQ随光强的升高达到较高水平,而遮荫叶片在较低的光强下即达到最大值,此时NPQ较低,遮荫叶片依赖于叶黄素循环的能量耗散水平较低。遮荫叶片较低的光合速率以及过剩光能耗散能力是其转入自然强光后光抑制严重的主要原因。     

砷对小麦生长和光合作用特性的影响

研究了水培条件下砷对小麦根系和地上部分生长速率、光合速率(Pn)、气孔导度(Gs)、胞间CO2浓度(Ci)和蒸腾速率(Tr)的影响.结果表明,随着营养液中砷浓度的提高,小麦根长生长量和地上部分生长量较对照减少;鲜重和砷的浓度呈显著负相关.在0～90mg/L 砷处理内,Pn、Gs、Tr都随砷的浓度的提高而降低;Ci呈先降低,后升高的变化.在As≤30 mg/L时Ci逐渐降低,气孔限制值Ls升高,使Pn下降,造成气孔性限制;而As>30 mg/L时,Ci升高,气孔限制值Ls下降,Pn降低,造成了非气孔性限制.叶片水分利用效率WUE和气孔限制值Ls在As≤30 mg/L时变化一致,都有所升高;但是当As>60 mg/L时,小麦趋于死亡,水分利用率降低.叶绿素含量在0～10mg/L As处理内,差异不显著,在较高砷浓度(As>30 mg/L)时叶绿素显著下降.这说明较低浓度的砷不会抑制小麦叶绿素的合成.砷主要是毒害小麦根系生长,造成植株体光合作用的气孔性限制和非气孔性限制出现,最终影响小麦的生长和发育.     

淹水解除后玉米幼苗形态及光合生理特征恢复

以郑单958为试验材料,在盆栽条件下研究了淹水及淹水解除后玉米幼苗根系、叶片形态、光合生理及植株的恢复生长.结果表明:(1) 淹水总体上抑制玉米幼苗根系生长,短期淹水(7d)导致根系总长度、根系表面积、根系体积均显著降低,随着淹水时间延长(14d)玉米根系产生大量不定根,使得根系总长度、根系表面积、根系体积显著升高(P＜0.01);(2)淹水条件下叶片生长同样受到抑制,玉米叶面积、叶型指数和可见叶片数均显著下降;(3)淹水条件下玉米幼苗的光合性能下降,光合色素总含量降低,但短期淹水(7d)后叶绿素a/b值提高;气孔限制(Ls)是淹水7d植株光合速率下降的主要因素,而非气孔限制则是淹水14d植株光合速率下降的主要因素.(4)淹水处理7d、14d后的玉米幼苗均能够恢复生长,但恢复生长速率随淹水时间延长而降低;在恢复生长过程中,光合生理指标恢复早于形态恢复,强光对于淹水后幼苗恢复生长具有明显的抑制效应.     

镉胁迫下硒对罗汉果组培苗光合特性的影响

实验以罗汉果组培苗为材料,室内栽培在内装市售营养土的塑料盆中,以0、10、50、100、200mg·kg-1浓度镉离子和1mg·kg-1浓度硒处理,培养20d后分析罗汉果幼苗的相关光合生理指标。结果表明:低浓度Cd2+对叶片叶绿素含量、光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)影响不大或稍有上升,但高浓度镉离子处理植株叶片的叶绿素含量、光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)明显下降;随Cd2+处理浓度的增加,叶片胞间CO2浓度(Ci)呈现上升趋势;加硒则延缓叶绿素下降,促进光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)上升,降低叶片胞间CO2浓度(Ci)。表明高浓度镉离子的毒害导致罗汉果组培苗叶片光合性能受到伤害,从而影响罗汉果幼苗生长。镉硒混合处理反映出硒对镉的毒害有缓解作用。     

彰武松、樟子松光合生产与蒸腾耗水特性

本文采用Li-6400光合测定系统对性成熟(18a)阶段彰武松(Pinus densiflora var.zhangwuensis)和樟子松(Pinus sylvestris var.mongolica)光合及蒸腾指标不同季节日变化进行了测定,并采用切枝蒸腾法对两个树种叶片气孔蒸腾和角质层蒸腾进行对比测定,评价了气孔开闭敏感性,探讨了两个树种光合生产与蒸腾耗水特性。结果表明：在同样生境条件下,彰武松比樟子松有较大的光合速率(Pn)和较小的蒸腾速率(Tr)。在5月和7月,彰武松的Pn和Tr日变化呈现明显双峰型,其Pn和Tr“午休”现象均主要受气孔限制;在10月呈单峰型。樟子松的Pn和Tr日变化在整个生长季均呈单峰型,而且,彰武松日光合量(DAP)均高于樟子松,是樟子松的163.4%(5月)、211.1%(7月)和183.6%(10月)。光响应曲线参数表明：在不同月份,彰武松最大光合速率(Pmax)均大于樟子松,且光饱和点(LSP)较高,光补偿点(LCP)较低。在任意被测时刻,彰武松气孔导度(Gs)和Tr都小于樟子松。彰武松具有较小气孔和角质层蒸腾速度,并且在同样干旱条件下,彰武松气孔下陷,其气孔的开闭反应更加敏感。彰武松水分利用效率(WUE)较高,约是樟子松的2.29倍。这些结果暗示,彰武松以其高的光合速率和低的蒸腾耗水特性,提高水分利用效率,以其敏感的气孔开闭机制和旱生叶片结构进而实现在干旱半干旱地区的速生特性。     

黄土丘陵区不同种植行距下柳枝稷光合生理日变化研究

以引进禾草柳枝稷为材料,在半干旱黄土丘陵区人工梯田设置20cm(L20)、40cm(L40)和60cm(L60)3种种植行距,比较研究了其光合生理参数日变化、地上部分生物量及土壤水分剖面分布特征,探讨其光合生理和水分利用特征与种植行距的关系。结果表明:(1)不同行距下,柳枝稷叶片净光合速率(Pn)日变化均呈双峰曲线,第一峰值均出现在10:00,第二峰值L40出现在14:00,L20和L60出现在16:00,具有明显的光合"午休"现象,且均由非气孔因素限制引起;柳枝稷叶片Pn日均值大小依次为:L60>L40>L20,且两两间差异显著。(2)柳枝稷叶片水分利用效率(WUE)日变化与Pn相似,分别在10:00和14:00达到峰值,日均值大小依次为:L60>L40>L20。(3)不同行距下,土壤体积含水量均随土层深度增加呈先增加后减少再增加的趋势,除0～50cm土层外,其它各土层土壤储水量均存在较大差异,0～380cm土层总土壤储水量表现为:L20>L40>L60。(4)柳枝稷地上生物量大小依次为:L20>L60>L40。研究发现,20cm行距的柳枝稷个体虽光合速率较低,但群体生物量和土壤储水量较高,所以柳枝稷在黄土丘陵区梯田的较优行距为20cm。     

不同浓度Ni、Cu处理对骆驼蓬光合作用和叶绿素荧光特性的影响水

以骆驼蓬幼苗为材料,采用盆栽试验研究不同浓度(0、50、100、200、400 mg·kg-1)Ni、Cu处理对骆驼蓬叶片光合作用、叶绿素荧光特性及生长状况的影响.结果表明:随着Ni浓度的增加,骆驼蓬幼苗叶片的光合色素含量、净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)、PS Ⅱ最大光化学效率(Fv/Fm)、PS Ⅱ电子传递量子产率(φpsⅡ)、光化学猝灭系数(qp)及各项生长指标均呈显著下降趋势,而细胞间隙CO2浓度(Ci)和非光化学猝灭系数(qn)呈显著增加趋势,其中Pn的下降主要是由非气孔限制所致;骆驼蓬幼苗叶片的光合色素含量、Pn、Gs、Tr、Ci、Fv/Fm、φpsⅡ、qp及各项生长指标均在50 mg·kg-1Cu处理时达到峰值,叶绿素a和b、Pn、Gs、Tr、Ci、Fv/Fm及各项生长指标值在100 mg·kg-1Cu处理时仍微高于对照,而后随Cu浓度的增加,光合色素含量、Pn、Gs、Tr、Ci、Fv/Fm、φpsⅡ、qp及各项生长指标均呈下降趋势,qN呈增加趋势,其中Pn的下降主要是由气孔限制所致.     

等渗盐分与水分胁迫对三角叶滨藜和玉米光合作用的影响

以溶液培养的三角叶滨藜(Atriplex triangularis)和玉米(Zeamays)为材料,测定了等渗的盐分和水分胁迫对2种植物光合作用的短期影响。结果表明:等渗的水分和盐分胁迫均会造成三角叶滨藜和玉米净光合速率(Pn)的降低,而且随着胁迫程度的增强,水分胁迫引起Pn下降的幅度要明显高于等渗的盐分胁迫;在较低渗透胁迫强度下,2种胁迫导致光合速率下降的主要原因是气孔限制;但在环境溶液渗透势为-1.0MPa时,水分胁迫对光合作用的影响逐渐转化成非气孔限制,而盐胁迫仍然是气孔限制起主要作用;由此可见,等渗透势的水分胁迫对2种植物光合系统的影响要明显大于盐分胁迫。     

Physiological Basis of the Difference in Net Photosynthetic Rate of Leaves between Two Maize Strains

Significant differences in net photosynthetic rate (P _N) of leaves between two maize (Zea mays L.) strains (Shuang 105 and 40×44) grown in the field were observed. At several growth stages, P _N of 40×44 was higher than that of Shuang 105 (from 10.3 to 32.5 %). Moreover, the strain 40×44 had a higher plant height, larger leaf area, lower chlorophyll content, and higher photochemical efficiency of photosystem 2 (PS2) (F_v/F_m and F/F_m) than strain Shuang 105. Shuang 105, which showed lower P _N, had lower stomatal conductances (g _s) but slightly higher intercellular CO₂ concentrations (C _i) than those of 40×44. Hence the differences in P _N between the two strains did not result from the difference in g _s, but probably from that in light reaction system.     

测墒补灌对不同穗型小麦品种耗水特性和干物质积累与分配的影响

在田间试验条件下, 以中穗型小麦(Triticum aestivum)品种‘山农15’和大穗型品种‘山农8355’为供试材料, 设置3个0-140 cm土层土壤相对含水量处理: W0 (拔节期65%, 开花期60%)、W1 (拔节期70%, 开花期70%)、W2 (拔节后8天70%, 开花后8天70%), 采用测墒补灌的方法补充土壤水分达到目标相对含水量, 对两个不同穗型小麦品种的耗水特性和干物质积累与分配进行了研究。结果表明: (1)两品种籽粒产量均以W0处理最低, ‘山农15’ W1和W2处理无显著差异, ‘山农8355’ W1处理显著高于W2处理; 两品种W1处理的水分利用效率和灌溉水利用效率均显著高于W2处理。‘山农15’ W1处理的籽粒产量和灌溉水利用效率分别显著低于和高于‘山农8355’的W1处理, 水分利用效率无显著差异; 两品种W2处理的籽粒产量、水分利用效率和灌溉水利用效率均无显著差异。(2)两品种总耗水量以W0处理最低, ‘山农15’ W1处理显著低于W2处理, ‘山农8355’两处理无显著差异; 两品种W1处理的土壤供水量及其占总耗水量的比例显著高于W2处理。‘山农15’ W1处理的总耗水量和灌水量占总耗水量的比例显著低于‘山农8355’, 土壤供水量占总耗水量的比例显著高于‘山农8355’; 两品种W2处理总耗水量, 土壤供水量及其占总耗水量的比例无显著差异。(3)两品种W1处理成熟期干物质积累量显著高于其他处理, W1处理提高了‘山农8355’开花后干物质积累量及其对籽粒的贡献率, 对‘山农15’无显著影响。‘山农15’ W1和W2处理成熟期干物质积累量显著低于‘山农8355’, 开花前贮藏同化物向籽粒的转运量和转运率、对籽粒的贡献率均显著高于‘山农8355’, 开花后干物质积累量及其对籽粒的贡献率低于‘山农8355’。综合考虑干物质积累与分配、籽粒产量、水分利用效率和灌溉水利用效率, W1处理是两品种节水高产的最佳土壤相对含水量处理。     

子莲新品种‘武植子莲1号’和‘武植子莲2号’产量与营养品质分析

对子莲（Nelumbo nucifera Gaertn.）新品种‘武植子莲1号’和‘武植子莲2号’与其他12个主栽子莲品种的莲子产量和品质性状进行分析,并通过隶属函数分析法对他们的营养品质性状进行综合评价。结果显示：不同子莲品种的产量和营养品质性状差异显著,同一品种在不同发育时期莲子的可溶性糖和淀粉含量等营养指标差异较大;鲜莲子的可溶性糖含量显著高于成熟莲子,而蛋白质和淀粉含量显著低于成熟莲子。与12个主栽子莲品种相比,‘武植子莲1号’在产量上较为突出,成熟莲子的淀粉含量达52.15%,是生产天然淀粉的优良品种;‘武植子莲2号’鲜莲子的直链淀粉和支链淀粉含量低,可溶性糖含量达23.43%,适合鲜食。隶属函数分析结果表明,‘武植子莲1号’和‘武植子莲2号’的综合营养品质较好,具有很高的应用价值。     

优质鲜食型甘薯新品种‘徐薯32’的选育及特性分析

甘薯新品种‘徐薯32’是以品质性状良好的‘徐薯55-2’为母本、‘红东’为父本,经有性杂交培育而成。该品种于2015年通过河南省农作物品种审定委员会审定。通过对‘徐薯32’农艺性状特征、生产力、抗病性、品质性状等进行研究,结果表明:‘徐薯32’地上部短蔓,薯块萌芽性好,耐贮藏,熟食口感佳;抗黑斑病,中抗根腐病与茎线虫病;鲜薯产量与对照‘徐薯22’相当,薯干和淀粉产量较对照分别增产15.24%和18.99%;‘徐薯32’块根主要营养物质含量均高于‘徐薯18’,其淀粉最高粘度值与崩解值较‘徐薯18’分别高6.52%和12.40%,糊化温度则略低于‘徐薯18’;淀粉粒径表面积与体积分布呈三峰、数目分布呈单峰,三类分布中淀粉颗粒总平均粒径均低于‘徐薯18’,降低幅度分别为12.22%、13.18%和2.22%。因此,‘徐薯32’具有良好的农艺性状与品质特性,可为鲜食型甘薯品种改良和应对市场需求奠定基础。     

Effects of low light stress on rubisco activity and the ultrastructure of chloroplast in functional leaves of peanut

Aims In recent years, intercropping system has become one of the major practice of peanut (Arachis hypogaea) cultivation in northern China because of the high land and energy utilization efficiency, to some extent compensating for the production loss caused by decreasing area of cultivation land. Intercropped peanut plants often have a lower pod yield compared with monoculture due to constraint on light availability. This study was conducted to explore the shade-tolerance mechanism in two peanut cultivars, ‘Huayu 22’ and ‘Baisha 1016’, that grew in an intercropping system, by studying chloroplast ultrastructure and rubisco activity under different levels of shading.
Methods A field experiment was conducted with three levels of light treatments, including full natural light (CK), 50% natural light indensity (NLI), and 15% NLI. The ‘Huayu 22’ was used as a shade-tolerant cultivar and the ‘Baisha 1016’ as a shade-susceptible cultivar based on previous studies. Experimental plants of both cultivars were shaded for 40 days from emergency in 2006. Rubisco activity, the number and shapes of chloroplasts and starch grains, and number of grana and granum lamella were investigated in functional leaves of plants in all treatments.
Important findings The functional leaves of peanut plants in the 50% and 15% NLI treatments had a lower rubisco activity than those in the CK treatment. In the ‘Baisha 1016’, the reduction in rubisco activity was 40.1% in the 50% NLI treatment and 59.4% in the 15% NLI treatment, respectively, compared to the CK treatment;whereas no significant differences were found among treatments in the ‘Huayu 22’ in the rubisco activity. Compared with the CK, the number of chloroplasts remained unchanged, the number of grana and lamella in grana increased, and the individual chloroplast was longer and in perfect development in the functional leaves of plants of the ‘Huayu 22’ grown in the 50% NLI treatment. In contrast, the number of chloroplasts, grana and starch grains of the ‘Huayu 22’ plants decreased significantly, the chloroplast membrane and grana lamella were damaged, the number of granum lamella increased, and the individual chloroplast became longer in the 15% NLI treatment. The number and ultrastructure of chloroplasts in the ‘Baisha 1016’ plants followed similar patterns of changes as those of the ‘Huayu 22’ in the 50% NLI treatment. For plants of the ‘Baisha 1016’ in the 15% NLI treatment, their chloroplasts became more roundly shaped, with decreasing number of grana lamella and increasing number of starch grains, compared with the CK. There were a greater decrease in the grana number and more damage in the grana lamella in plants of the ‘Baisha 1016’ than those of the ‘Huayu 22’. In conclusion, the shade tolerance of the ‘Huayu 22’ resulted from lack of changes in rubisco activity and less damage in the ultrastructure of chloroplasts when under low light stress compared with the ‘Baisha 1016’.     

铁皮石斛叶色突变体的叶绿体超微结构、光合色素和叶绿素荧光特性的研究

以铁皮石斛(Dendrobium officinale Kimura et Migo)(‘TP35’)经自然突变的白绿杂色突变体(‘TP-MA’)和太空诱变的绿黄杂色突变体(‘TP-MG’)为材料,研究不同光照强度(0、50、100μmol·m^-2·s^-1)处理后,植株叶片的叶绿体超微结构、光合色素含量以及叶绿素荧光动力学参数的变化规律,并阐明叶色突变体与正常植株光合特性的差异。结果显示,‘TP-MA’和‘TP-MG’的叶绿体形态均发生了一定程度的缺失,且叶绿体分布不均匀、无规则,基粒片层结构不完整且排列疏松,基本与其表型性状相一致。‘TP-MA’光合色素的含量和叶绿素荧光参数F v/F m、ΦPSⅡ及F v′/F m′等显著低于‘TP35’,但非光化学淬灭系数(NPQ和q P)则相对较高;‘TP-MG’的光合色素含量及叶绿素荧光参数均低于‘TP35’,但差异不显著,且对较强的光照(100μmol·m^-2·s^-1)条件具有一定的适应性。研究结果表明不同光强处理后,铁皮石斛叶色突变体的叶绿体结构和光合生理指标均发生了不同程度的变化,且对植株的叶绿素含量及荧光参数产生一定影响,过低和过高的光照强度均不利于植株的正常生长。     

不同番木瓜品种植株感染环斑花叶病毒后PAL、PPO、POD活性的变化

对不同品种番木瓜接种环斑花叶病毒后,测定植株苯丙氨酸解氨酶(PAL)、多酚氧化酶(PPO)、过氧化物酶(POD)的活性变化,比较各品种的抗病性。结果表明,未接种的5个品种间PAL、PPO、POD活性差异较小,其酶活性水平次序为马来10号> 蜜红3号> 马来6号> 马来2号> 台农2号。接种后,5个品种的PAL、PPO、POD活性明显高于各对照水平,其中马来10号变化最突出,台农2号变化最缓慢。     

高温对水稻开花期剑叶抗氧化酶活性及基因表达的影响

以杂交水稻‘Ⅱ优838’为研究材料,检测了高温胁迫下‘Ⅱ优838’开花期剑叶中叶绿素含量、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和过氧化物酶(POD)活性及SOD、CAT、POD基因的表达水平。结果显示,高温胁迫使‘Ⅱ优838’剑叶中叶绿素含量及叶绿素a和叶绿素b含量的比值(Chl a/Chl b)降低且下降幅度显著低于‘冈优725’(对照);SOD和POD活性增高且增幅显著大于‘冈优725’,但CAT活性降低且降幅显著小于‘冈优725’;热胁迫使‘Ⅱ优838’剑叶中SOD、CAT和POD基因的表达量显著增加。说明‘Ⅱ优838’在开花期遭遇高温胁迫后能保持较高的光合效率,并通过提高抗氧化保护酶的基因表达水平以维持较高的活性来应答高温胁迫,这为深入剖析水稻高温胁迫下的生理反应和适应机理提供了参考。     

Photosynthetic characteristics in different peanut cultivars under conditions of drought and re-watering at seedling stage

Aims In China, peanut (Arachis hypogaea) is mainly cultivated in the semi-arid and rain-fed areas, and drought is the most prominent environmental stress to its growth. However, studies on the physiological responses of different peanut cultivars to drought and re-watering are lacking. Our objectives were to investigate the relationship between photosynthetic characteristics and drought tolerance, and to explore the ability to recover from drought damage in different peanut cultivars.
Methods A pot experiment was conducted with artificial water stress treatment, and the photosynthetic characteristics were determined in twelve peanut cultivars under the conditions of drought stress and re-watering at the seedling stage. The drought tolerance was assessed by drought resistance coefficient of biomass in seedling. The recovery capacity was assessed by compensatory growth of plant.
Important findings Five cultivars, including ‘Shanhua 11’, ‘Rugaoxiyangsheng’, ‘A596’, ‘Shanhua 9’, and ‘Nongda 818’, showed over-compensatory growth after re-watering, and their capacity of compensatory growth had significant positive correlation with drought tolerance (p < 0.01). The net photosynthetic rate (P_n), stomatal conductance (G_s), intercellular CO₂ concentration (C_i), maximum photochemical efficiency (F_v/F_m), PSII actual quantum yield (ΦPSII), and photochemical quenching coefficient (q_P) all decreased over the course of drought stress, and then increased following re-watering, with the amplitude of changes being smaller in the more drought tolerant cultivars. Seven days of drought did not result in significant differences in the photosynthetic characteristics among majority of the peanut cultivars tested (p > 0.05). After 14 days of drought, the values of photosynthetic variables differed significantly among the peanut cultivars with different drought tolerance (p < 0.05). The values of P_n, G_s, Φ_PSII, F_v/F_m, and q_P in the cultivars ‘Shanhua 11’, ‘Rugaoxiyangsheng’, ‘A596’, and ‘Shanhua 9’fully recovered five days after re-watering, while those in the cultivars ‘79266’, ‘ICG6848’, ‘Baisha 1016’, and ‘Hua 17’ did not fully recover even after 10 days of re-watering; the values of those photosynthetic variables were significantly greater (p < 0.05) in the more drought tolerant cultivars following re-watering. Correlation analysis showed that the drought tolerance was significantly and positively correlated with P_n, Φ_PSII, F_v/F_m, and q_P after 14 days of drought stress and after five days of re-watering, respectively (p < 0.01). Therefore, under drought stress at 40% of relative water content (RWC) for 14 days and after five days of re-watering at the seedling stage, the P_n, Φ_PSII, F_v/F_m, and q_P could be used for identifying the level of damage and recovery capacity of peanut cultivars. The cultivar ‘Shanhua 11’ can be used as a reference for drought adaptability identification in peanut.     

下层土壤容重对玉米生育后期光合特性和产量的影响

在耕层（0～20 cm）土壤容重不变情况下,采用池栽方法研究了下层（20～40 cm,40～60 cm）土壤容重变化对玉米生育后期光合特性和产量的影响.结果表明：当下层土壤容重不同时,玉米的光合速率（P_n）和产量都存在显著差异,随着下层土壤容重的增加,叶片P_n和产量降低,下层土壤容重越大,降幅越大.不同处理玉米叶片的P_n和细胞间隙CO₂浓度（C_i）的变化趋势不同,P_n早晨和傍晚较低,中午较高,且随着下层土壤容重的增加而降低, C_i的变化趋势则相反.气孔限制值（L_s）和气孔导度（G_s）也随着下层土壤容重的增加而降低. 随着玉米生育进程,P_n、L_s和G_s不断下降,而C_i不断升高.