以食葵中熟品种LD5009为材料,在石羊河中游绿洲设3个种植密度(D1:39 990株/hm2,D2:49 990株/hm2,D3:66 660株/hm2)和3个行距(R1:0.7m,R2:0.6m,R3:0.5m),研究密度与行距对向日葵干物质转运及产量形成的影响.结果表明,不同密度与行距配置下向日葵干物质积累与分配规律不同.随着密度增加,收获指数先增大后降低(0.32-0.35-0.31).花前干物质转运量和转移率随密度增大而增加,而花后干物质积累量和转移量随密度增加而降低.D1、D2以R2的花前干物质转运效率较低,分别为6.58％和8.22％,但花后干物质积累量较高,分别为3117和3088kg/hm2.向日葵籽粒灌浆过程符合Logistic方程,随着密度的增大,平均灌浆速率从1.72g/(千粒·d)降低至1.06g/(千粒·d),灌浆持续期从47.17d延长至55.84d.随着行距增大,平均灌浆速率先增大后降低[1.39-1.49-1.34g/(千粒·d)],灌浆持续期先降低后增加(51.09-49.74-51.78d).随着种植密度增加,向日葵群体有效花盘数和秕籽率增大,单盘粒数、千粒重和单盘粒重降低,各产量构成因子相互作用影响产量形成.石羊河流域绿洲向日葵高产种植适宜密度为49 990株/hm2,适宜行株距配置为0.60m×0.33m.

以食葵中熟品种LD5009为材料,在石羊河中游绿洲设3个种植密度(D1:39 990株/hm2,D2:49 990株/hm2,D3:66660株/hm2)和3个行距(R1:0.7m,R2:0.6m,R3:0.5m),研究不同密度与行距配置对向日葵盛花期冠层结构、光合特性以及产量构成的调控作用.结果表明,D3R2处理下茎粗降低至2.50cm,株高和冠层下部叶向值分别增加至187cm和50.50.高密度能显著增大冠层中部叶面积指数(LAI),而中等密度有助于平衡冠层中、下部光环境,保证冠层底部较高的LAI,D2R2处理下LAI可达5.20,其中冠层下部为1.97.叶绿素含量、净光合速率(Pn)和蒸腾速率(Tr)均随密度的增加而降低,且差异集中体现在冠层下部,D3R2处理冠层下部叶绿素含量、Pn和Tr分别降至1.09mg/g、-1.87μmol/(m2,s)和 1.33mmol/(m2.s).产量、盘粒数、千粒重与株高、冠层中、下部叶向值、冠层中、下部LAI呈负相关,与茎粗、冠层中及下部透光率、冠层下部叶绿素含量、Pn和Tr呈正相关.本试验条件下,种植密度为49 990株/hm2且0.6m行距配置可确保适宜的冠层结构与光合特性,为高产提供保障.

为探索茄果类蔬菜秸秆废弃物肥料化利用途径,于2019年设定番茄秸秆全量原位还田及腐解菌剂的配施试验:C,无番茄秸秆+无腐解菌剂;T1,番茄秸秆+无腐解菌剂;T2,番茄秸秆+菌剂1'源动力'(1 kg·666.7m-2);T3,番茄秸秆+菌剂2'有纯'(3 kg·666.7m-2);T4,番茄秸秆+菌剂3'沃宝'(2 kg·666.7m-2),分析其对土壤特性和下茬番茄长势和产量的影响.结果表明:与对照相比,番茄秸秆原位还田降低土壤pH,显著增加土壤有机质、速效磷和速效钾含量(P<0.05),其中成熟期T2处理有机质含量分别比T1、T3、T4和C显著高7.3％、8.1％、14.2％和26.9％;番茄秸秆腐熟后T2处理速效磷含量分别比C、T1、T3、T4处理高24％、11.3％、4.4％和8.7％.番茄秸秆还田+腐解菌剂显著提高细菌和放线菌数量,其中放线菌数量远高于细菌和真菌数量.番茄秸秆还田对番茄的生长势和产量影响显著,增产的主要原因是番茄秸秆还田提高了单株坐果数,其中菌剂'源动力'的增产效果优于'有纯'和'沃宝'.分析产量及其构成性状与土壤环境因子间的关联性发现,土壤有机质含量、速效磷含量、放线菌数量与单株坐果数和单株产量间呈正相关关系,其中有机质与单株坐果数的相关性(R2=0.75),高于其与单株产量间的相关性(R2=0.31).以上结果表明,番茄秸秆原位还田配施腐解菌剂改善了土壤微生物数量比例,增加了土壤速效养分和有机质含量,通过改善土壤特性促进番茄植株的生长,使单株坐果数增加而提高产量.

为优化甜瓜/向日葵间作模式节水灌溉关键技术,提高绿洲灌区灌溉水分利用效率.试验以甜瓜和向日葵为试材,研究9种灌溉制度下甜瓜/向日葵间作系统和2种作物单作的叶片水分状况和水分利用效率.结果 表明,甜瓜/向日葵间作系统的水分效率显著高于甜瓜单作和向日葵单作,分别提高30.3％和107.8％,间作显著提高了甜瓜成熟期叶片的水分饱和亏,对相对含水量无显著影响,却降低了向日葵开花期和成熟期叶片的相对含水量和水分饱和亏.间作不同灌溉次数下,灌水8次和灌水9次有利于提高间作系统的水分利用效率.间作不同灌水定额下,灌水8次和灌水9次处理下,灌水定额为225 m3/hm2的水分利用效率显著高于灌水定额为450 m3/hm2、和300 m3/hm2,分别提高47.8％、21.4％和37.6％、31.0％.间作不同间作灌溉次数下,灌水7次有利于提高甜瓜成熟期叶片的相对含水量,灌水8次有利于提高甜瓜成熟期叶片水分饱和亏和向日葵成熟期叶片水分饱和亏,灌溉次数对向日葵叶片相对含水量无显著影响.间作不同灌水定额下,灌水定额为225 m3/hm2有利于提高甜瓜叶片的相对含水量、水分饱和亏和向日葵叶片的相对含水量,灌溉定额对向日葵叶片水分饱和亏无显著影响.在河西绿洲灌区甜瓜/向日葵间作系统条件下获得较高水分利用效率和改善叶片水分状况较适宜的灌溉制度为全生育期灌水8次、灌水定额225 m3/hm2.

植物化学计量特征对阐明生物地球化学及生态过程对全球变化的响应至关重要.研究不同氮磷(N、P)添加处理对荒漠植物生态化学计量特征的影响,可从化学计量的角度理解植物对环境变化的响应,为预测全球变化背景下植物和营养元素的相互作用提供思路.以黑果枸杞(Lyci?um ruthenicum)为材料,设置3个氮磷添加量和比例,通过大田试验研究了黑果枸杞C:N:P化学计量特征对氮磷添加的响应,比较分析了器官间的化学计量特征.结果表明:(1)氮磷添加对黑果枸杞不同器官碳(C)含量的影响较小,随氮磷添加量的增加,细根N含量显著增大;随氮磷添加比例的提高,非根器官N含量显著增加,根系P含量显著降低;氮磷添加比例和添加量的交互效应显著影响了根系和果实N、P含量及茎P含量.(2)低氮磷添加比处理降低了器官碳磷比(C/P),提高了碳氮比(C/N),而高氮磷添加比处理与之相反,各器官氮磷比(N/P)维持在相对稳定的水平,黑果枸杞通过调整养分保存策略以保守的养分利用方式抵消环境元素化学计量的变化.(3)黑果枸杞化学计量特征体现出器官功能差异性,叶片N含量和N/P显著高于其他器官,茎C/N最高,粗根C含量和C/P最高,细根N、P含量和N/P较高,果实P含量最高.相对于C,代谢活跃器官(叶、细根、果实)比非代谢活跃器官(茎、粗根)需要更多的N和P.研究结果有助于更好地从元素与植物功能的角度理解荒漠植物化学计量特征对氮磷添加的响应.

非结构性碳水化合物(NSC)在植物生长、繁殖、防御和生存等方面发挥着基础性作用.为探究黑果枸杞(Lyciumruthenicum)NSC积累的器官间规律及其对土壤氮磷供应水平的响应,以3年生黑果枸杞为对象,测定了3个氮磷比例和供应量条件下根茎叶NSC含量.结果表明:(1)黑果枸杞根、茎、叶NSC组成均以可溶性糖为主,淀粉约占37.3％;器官NSC含量粗根和细根＞叶片＞新梢＞一二年生枝条,各器官可溶性糖含量粗根和细根＞叶片＞新梢＞一年生枝＞二年生枝;淀粉含量细根＞粗根＞二年生枝＞一年生枝＞叶片和新梢;糖淀比叶片＞新梢＞粗根＞一年生枝＞二年生枝＞细根.(2)氮磷比和供应量对黑果枸杞根系可溶性糖含量无显著影响,对茎叶NSC含量的影响存在显著交互效应.氮磷比5∶1时,茎叶NSC含量随氮磷供应量升高而增加;氮磷比15∶1时,茎叶NSC含量随氮磷供应量增加显著降低;氮磷比45∶1时,茎叶NSC含量随供应量的增加而显著升高.(3)一年生枝NSC含量于萌芽前达到最大值(5.05％DW),于春梢旺盛生长期降至最低值(3.79％DW);二年生枝NSC含量在萌芽前最低(4.23％DW),于秋季落叶期达到最大值(4.33％DW).(4)粗根和叶片NSC含量与一二年生枝NSC含量负相关;新梢NSC含量与叶片NSC、二年生枝淀粉含量正相关;一年生枝可溶性糖含量与二年生枝可溶性糖含量负相关;二年生枝淀粉含量与根系淀粉和NSC含量负相关.黑果枸杞通过调整各器官NSC积累及分配应对生长季各器官能量需求和环境氮磷供应变化,在氮磷限制环境中将更多NSC储存在根系,可平衡当前碳同化与未来能量需求的矛盾,增强个体生存能力,也为黑果枸杞应对非生物逆境胁迫提供更大的灵活性.

以香瓜茄为材料,在日光温室条件下,于果实发育期叶面喷施沼液肥,研究沼液肥施用浓度及其与土壤追肥配合对香瓜茄叶片光合特性和果实产量与品质的影响.结果表明,稀释100倍沼液肥处理的叶片总氮和叶绿素质量分数分别为35.7 g·kg-1和1.129 mg·g-1,显著高于稀释400倍沼液肥的处理和对照,沼液肥配合土壤追肥时叶片总氮和叶绿素质量分数明显高于只喷施沼液肥的.香瓜茄果实膨大期叶片净光合速率高于开花期和果实成熟期,叶面喷施沼液肥后叶片平均Pn(10.2μmol·m-2·s-1)显著高于对照(7.88μmol·m-2·s-1),沼液肥配合土壤追肥的Pn(10.30μmol·m-2·s-1)显著高于单喷沼液肥处理(8.94μmol·m-2·s-1).叶面喷施中,高浓度沼液肥能显著提高香瓜茄果实产量和品质,两个土壤施肥处理平均单果质量比对照分别增加16.8％和22.2％,小区产量提高18.9％和30.4％,果肉硬度提高13.9％和23.2％,可溶性固形物含量增加6.9％和15.3％,喷施沼液肥结合土壤追肥处理的效果优于单喷沼液肥.香瓜茄果实生育期配合土壤追肥的沼液适宜喷施浓度为浓缩沼液稀释100倍.

Analyzing the effects of nutrient addition on the functional traits of desert plants is important for revealing the responses of desert plant species to environmental changes. In this study, we examined the responses of whole plant, root, stem, leaf and fruit traits of Lycium ruthenicum to the addition of N and P, with an experiment with three (low, medium and high) N and P addition levels and three N/P ratios (5:1, 15:1 and 45:1). The results showed that functional traits of L. ruthenicum had divergent responses to NP addition level and N/P ratio. With the increases of NP addition level, the biomass and specific leaf area were increased, while the root-shoot ratio, leaf dry matter content, root tissue density and specific root length were decreased. Belowground biomass, specific root length and net photosynthetic rate increased with the increases of N/P ratio. The coefficient of variation of 17 functional traits was 7.3%-69.1%. The biomass, root-shoot ratio and speci-fic root length were sensitive traits to NP [plastic index (PI)>0.5], with greater variability (49.4%-69.1%), whereas the leaf length-width ratio, leaf thickness, leaf tissue density, and leaf stem dry matter content were conservative traits (PI<0.20). The results of principal component analysis (PCA) showed that the position of L. ruthenicum in the multivariate feature space exhibited lateral migration with the changes of NP addition levels, with a tendency of higher aboveground and belowground biomass and a lower root-shoot ratio. Leaf tissue density was negatively related to leaf thickness and specific leaf area. Leaf dry matter content was negatively correlated with leaf thickness and specific leaf area but positively associated with leaf tissue density. Biomass had a positive correlation with specific leaf area and a negative relation to specific root length. The results of stepwise regression analysis showed that specific root length, specific leaf area and leaf net photosynthetic rate were major functional traits affecting the biomass of L. ruthenicum. L. ruthenicum adapted to the fluctuations of soil nutrient environment through changing resource utilization strategy, altering root carbon allocation, and also the trade-off and covariance among traits and inconsistent response.

通过选取阿拉善地区3个典型霸王群落为研究对象,研究霸王器官间(根、茎、叶)生态化学计量比特征及非结构性碳水化合物(Non-structural carbohydrates,NSCs)的变化,以便加深对霸王生存策略的理解,更好的服务于荒漠生态系统的生态恢复.结果 表明:霸王茎和叶中可溶性糖(Solu?ble sugar,SS)、淀粉(Starch,ST)和NSCs含量随干旱加剧均显著降低.根系中SS和NSCs在3个样点间差异不显著,ST先降低后增加,ST含量在Plot3中比在Plot1和Plot2中高19.3％和31.2％.干旱使霸王根、茎、叶中N、P含量显著下降,使根、茎、叶中C:N和C:P显著增高,叶片N:P<14.Plot1中霸王器官间SS、SS:ST和NSCs含量表现为叶片>根>茎,ST含量为茎>根>叶片;Plot2和Plot3中霸王器官间SS、ST和NSCs含量均为根>茎>叶片.3个样点中叶片相较于茎干和根系具有高的N、P含量和低的C:N和C:P.NSCs与C:N:P间的关系表明:根、茎、叶中的N含量与SS正相关,叶片N含量与根系ST负相关.以上结果表明霸王的茎干和根系可能扮演"营养库"的角色,霸王通过提高N、P利用效率来减缓水分亏缺使其生长受到N限制的影响.霸王通过调节器官间NSCs的积累及分配来适应干旱,采取将根系中ST转化为SS来调节渗透势的策略;并随干旱加剧将更多的碳水化合物投资分配到根部,以ST的形式存储,而N是影响霸王根系中ST与SS间转化和ST存储的关键元素.

: The Hexi Corridor is located in the middle of China, in the depression between the Tibetan Plateau and the Inner Mongolia Plateau; the Siberian High is unimpeded here. The ecology of the Hexi Corridor directly affects the overall ecological situation of China. Therefore, it is of great practical significance to evaluate water security in the inland river basins of the Hexi Corridor. Most research on water security used the traditional pressure-state-response model and its extended model; the optimization and calibration of an evaluation index system have hardly been mentioned. This article introduces the society-economic-water ecological composite system model for water security evaluation. This water ecological security evaluation index system was constructed from natural and socio-economic attributes of water security, and the index system was optimized by fuzzy system analysis and improved niche theory. The optimized and calibrated index system was used for the fuzzy comprehensive evaluation of the water security of inland river basins in the Hexi Corridor from 2014 to 2017. The improved niche theory was used to calculate the niche width of the evaluation index. The improved niche width values of B3 (industrial added value), B13 (river base flow), B17 (water yield coefficient), and B20 (water diversion) were the largest, which have relatively little influence on the index system. They were eliminated in the optimized index system. Fuzzy system analysis was used to calculate the weight of the evaluation index. In the optimized index system, indexes C11 (perennial average precipitation), C16 (water storage), C17 (surface water supply), C18 (groundwater resource supply), C24 (ecological environment water consumption), and C29 (water-saving irrigation area) have the largest cumulative index weight, at 36.18%. The fuzzy comprehensive evaluation index of water security in the Heihe River Basin was above 0.45. The fuzzy comprehensive evaluation index of the Shiyang River Basin decreased from 0.5 in 2014 to <0.3 in 2017. The fuzzy comprehensive evaluation index of the Shule River Basin hovers around 0.2. The results showed that increasing investment in water conservation, developing water-saving irrigated agriculture, and protecting the ecological environment were the most effective measures to improve water security in inland river basins. From 2014 to 2017, the water security situation in the Heihe River Basin improved, whereas the water security in the Shiyang and Shule River Basins has deteriorated. These basins should be taken as key governance areas, so the trend of the overall improvement and partial deterioration of water security in inland river basins continues. The results provided theoretical and data support for water administration and environmental management departments in the Hexi Corridor to make ecological risk decisions and provided new ideas for the high-quality development of Gansu Province river basins.

对祁连山中段冰沟流域土壤有机C、N、P含量垂直分布与化学计量特征及其影响因素进行研究.结果表明:冰沟流域土壤有机C、N、P含量在各样点随土层深度而降低,并在表层土中聚集较明显;在0-40 m土层中,土壤有机C、N、P平均含量随海拔升高总体呈现先增高后下降的趋势,在中、高海拔处最高,P含量变异较小.0-40 cm土层中土壤C/N在海拔3 128-2 814 m处高于其他海拔,在3 075 m处C/N最高,土壤C/N、C/P随海拔升高总体呈下降趋势,均在中高海拔处最高,而土壤N/P在海拔3 454 m处最高,在低海拔2 814 m处最低.不同植被类型土壤的C/N、N/P差异性不显著,而土壤SOC/P差异显著,3种植被类型影响土壤C/N和C/P的大小为乔木林＞高山灌丛＞高山草地,而土壤N/P为灌丛＞乔木林＞高山草地;植被类型、海拔是影响土壤C、N、P含量和化学计量比的主要因素,其次为盖度、坡向.

Studies on the survival and growth strategies of the dominant species Nitraria tangutorum in desert ecosystem can help serving ecological restoration and soil desertification prevention. The N. tangutorum samples were collected from three plots where differed in relative moisture and drought degree showed as Plot1 < Plot2 < Plot3, to explore the C ∶N ∶P stoichiometry and non⁃structural carbohydrate (NSCs) accumulation and allocation in organs of roots, stems and leaves. Meanwhile, the concentrations of soil organic matter, total nitrogen and phosphorous were analyzed in the same sites. The

: In arid ecosystems, high temperatures and low rainfall result in reduced carbon fixation. Non-structural carbohydrates (NSCs) (including soluble sugars and starch) represent the products of plant photosynthesis and are mainly involved in the balance between C acquisition and expenditure in life processes. NSCs also reflect the amount of plant carbohydrates that can be used to resist adverse environmental conditions. The C:N:P stoichiometry of plants is associated with important ecological processes, such as an organism ’ s ability to adapt to environmental stresses. Leaf N is the basis of chlorophyll formation for direct use in photosynthesis. Plant P is indispensable for the transportation of photosynthetic products. Thus, the C:N:P variations in plants are directly affected by the rate of photosynthesis. Leaf N concentration has been found to be positively correlated with NSC fixation ability, and P has been identified as the key element of plant metabolism. Accordingly, leaf photosynthetic capacity and NSC synthesis are not only affected by leaf N concentration but also closely related to P concentration. Therefore, it is important to study the relationship between NSCs and C:N:P stoichiometry in Zygophyllum xanthoxylon to improve our understanding of its survival and growth strategies to xeric conditions. Samples were collected from three dominant communities of Z. xanthoxylon across Ningxia and Inner Mongolia Provinces in northwestern China that differed in mean annual relative air moisture (Plot 1>Plot 2>Plot 3). Plant and soil samples were collected during the growing season (August) of 2014. Soluble sugars and starch are commonly studied NSCs. Plant samples were divided into leaves, stems, and roots to analyze the concentrations of starch (ST), soluble sugar (SS), C, N, and P. The concentrations of SS, ST, and NSCs in stems and leaves decreased from Plot 1 to Plot 3. N and P concentrations decreased, whereas C:N and C:P ratios increased with increasing xeric conditions in roots, stems, and leaves. N:P ratios in leaves were all below 13, lower than the critical ratio of 14 in all three plots, suggesting that N is the limiting factor for the growth of Z. xanthoxylon in xeric environments. Variations were inconsistent in NSCs and C:N:P stoichiometry among the organs. N and P concentrations in leaves were higher than those in stems and roots, while C:N and C:P ratios in leaves were lower than those in stems and roots in three plots. The correlation of C:N:P stoichiometry with NSCs showed that N concentrations positively correlated with SS concentrations in roots, stems, and leaves, whereas N concentrations in leaves negatively correlated with ST in roots. Stems and roots may act as nutrient sinks, and Z. xanthoxylon may alleviate water deficit-caused N limitation by increasing N and P use efficiency. Z. xanthoxylon adapted to drought by regulating the accumulation and distribution of NSCs among organs. Osmotic potential is regulated by conversions between ST and SS in the root system; more carbohydrates were allocated to roots and stored as ST with enhancing drought stress. N is the key factor in the transformation of ST to SS and ST storage in the root system.

为了探究3种UV-B(ultraviolet-B,波长为280～315 nm的紫外光)辐射强度对香蒲(Typha orientalis)叶片光合特性和叶绿体超微结构的影响,于2017年5月19日至7月17日,在甘肃农业大学室外实验基地,构建模拟垂直潜流人工湿地,在其中栽种香蒲幼苗;在3种UV-B辐射强度[168 μw/cm2(自然光照下)、210 μw/cm2和252 μw/cm2]下,测定香蒲叶片光合色素含量和光合特性指标,并观察其叶绿体超微结构.研究结果表明,UV-B辐射增强显著减小了香蒲叶片的光合色素含量,且随着辐射强度增大,光合色素含量减小量增大;UV-B辐射增强显著减小了香蒲叶片的净光合速率、气孔导度和蒸腾速率,增大了胞间CO2浓度,UV-B辐射强度增强的条件下香蒲叶片光合速率减小的主要原因是非气孔因素;在UV-B辐射增强条件下,香蒲叶片叶绿体超微结构遭到破坏,表现为叶绿体数目减少,叶绿体结构变形,体积膨大,形态臃肿,叶绿体中出现淀粉颗粒,破坏作用随辐射强度增大而加剧.

作为生态环境至关重要的因素,水生态安全格局是生态安全格局的关键组成部分,科学评估水生态安全状况,进行生态系统管理及保护,对促进经济社会发展具有重要意义.选取甘肃地区17个流段为研究对象,基于SENCE(社会-经济-自然复合生态系统)概念构建涵盖经济发展、社会进步、自然资源、生态环境4方面33指标的初步水生态安全评价指标体系,基于改进生态位理论结合模糊系统分析对初步水生态安全评价指标体系进行优化,最终得到28指标构成的水生态安全评价优化指标体系,运用优化后指标体系对17流段2016-2018年间水生态安全状况模糊综合评价.结果表明:水生态安全状况良好(一级、二级)以上占比分别为35.3％、41.2％、35.3％,一般(三级)占比分别为57.8％、52.0％、46.1％,较差(四级)占比分别为23.5％、11.8％、11.8％,大致呈正态分布,且年际变化小,基本保持稳定.年平均降水量、河川基流量、地表水源供应量、生态环境用水量、节水灌溉面积等指标累计指标权重达47.75％,是影响水生态安全状况的主要影响因子.

沼液富含有机质、氮、磷、钾、钠及各种微量元素,是非常具有回收价值的一种天然有机肥料资源.针对大型沼气生产企业面临的沼液产量大、处理成本高、储存运输困难和营养物质含量偏低等问题,文章通过膜分离浓缩装置对其进行浓缩试验,研究在浓缩过程中不同孔径(截留分子量)滤膜的膜通量与运行压力之间的关系,结果表明:微滤、超滤、纳滤的最佳工作压力分别为0.15 MPa,0.3 MPa,0.8 MPa.在最佳工作压力条件下,微滤膜平均通量为11.38 L·m-2h-1;10000D和5000D超滤膜平均通量为127.93 L·m-2h-1和87.08 L·m-2h-1;5000D和10000D超滤膜透过液的600D纳滤膜平均通量为159.39 L·m-2h-1和165.62 L·m-2h-1,150D纳滤膜平均通量为39.29L·m-2h-1和29.38 L·m-2h-1.

为了探讨籽瓜叶片光合能力对源库调节的响应,以种子大小显著不同的3个籽瓜品种为材料,于开花坐果期通过整枝、摘叶、疏果将叶果比分别调整为10、20、30、40、50,并分别于幼果期、果实膨大期、果实成熟期测定叶片叶绿素含量及气体交换速率,收获后测定果实产量.结果表明,籽瓜功能叶叶绿素含量(SPAD值)、净光合速率(Pn)、气孔导度(Gs)和蒸腾速率(Tr)随果实生育期演进逐渐降低,胞间CO2浓度(Ci)逐渐增大.3个供试品种间SPAD、Pn、Gs、Tr和Ci差异显著,大种子品种H26的气体交换参数(Pn、Gs、Ci、Ti)显著低于中等种子品种H14,H14显著低于小种子品种H3,但SPAD和Ci变化规律相反.叶片SPAD、Pn、Gs、Tr均值及其果实生育期降幅均随叶果比增大而显著降低(叶果比50除外),但叶片SPAD值和气体交换参数变化幅度无显著的品种间差异,说明一定范围内降低叶果比能提高叶片光合能力,但摘叶处理或叶果比过高均会加速叶绿素降解,诱发叶片衰老.3个品种单株果实产量随叶果比增大而提高,50(1.18 kg)>40(1.17 kg)和30(1.17 kg)>20(1.16 kg)>10(0.87 kg),H3单株果实产量(0.88 kg)显著低于H26(1.20 kg)和H14(1.25 kg).以上结果表明,适宜范围的源库比能够提高籽瓜叶片光合能力,延缓叶片衰老,有利于籽瓜果实高产.

在石羊河中游田间条件下，通过灌水和施肥调节黑果枸杞生长。测定不同时期黑果枸杞茎、叶生长量及其化学计量学特征变化，分析器官水平生长速率与化学计量学特征的关系，验证生态化学计量学理论“生长速率假说”。灌水施肥显著促进了茎长、基径和叶片长、宽及叶干重的生长（P <0.05），而茎长、基径、叶面积和叶干重的相对生长速率与对照之间无显著差异。各处理下黑果枸杞新梢C含量及C∶N、C∶P随生育期进程呈增加趋势，而N、P及N∶P呈降低趋势；灌水和施肥处理后茎C含量及C∶N、C∶P、N∶P低于对照，茎N、P含量高于对照。各处理叶片C、N、P含量在生育期内呈降低趋势，而C∶N、C∶P及N∶P呈增加趋势；灌水和施肥后叶片C含量及C∶N、C∶P、N∶P低于对照，叶片N、P含量高于对照。茎C含量及C∶N、C∶P显著高于叶片（P <0.05），而N、P含量及N∶P显著低于叶片（P <0.05）。生长速率假说认为，生物个体的生长速率与体内的N∶P、C∶P具有负相关关系, 与N、P含量呈显著的正相关关系。各处理黑果枸杞茎、叶的生长速率与其N、P含量及C∶P、N∶P总体相关性不显著。表明施肥灌水调节下黑果枸杞茎叶生长及化学计量学特征不支持生长速率假说。

香瓜茄俗称"人参果",是原产于南美洲安第斯山北麓高原地区的茄属植物,学名为Solanum murcatum Ait.我国大陆于1980年引入该植物,先后在广东、四川、河南等地试种,现已在甘肃河西等地区具有一定种植规模.本文从香瓜茄的原产地与传播、植物学性状、果实营养成分、种植方式和病毒病防治概述了"人参果"正名的必要性.在以往的文献和媒体报道中,涉及香瓜茄的报道多用"人参果"指代,但"人参果"一词在中文文献中可指代完全不同的植物产品,易引起信息混乱,常给读者以误导,不利于学术交流和商品的推广.考虑到该植物的系统分类和产品特性,建议在今后的中文学术文献中将Solanum murcatum Ait统称为"香瓜茄".