水溶肥中镁不同添加量对辣椒光合特性、干物质积累与分配的影响

以线椒"8819"为试验材料,采用盆栽的方法,研究镁元素在水溶肥中不同添加量(0、0.25%、0.50%、1.00%、2.00%、4.00%,均以MgO计)对辣椒光合特性、干物质积累与分配的影响。结果表明:在低添加量下(0~2.00%时),添加镁元素提高了辣椒的光合性能,改变了辣椒干物质的积累与分配规律,随着镁元素添加量增加,辣椒各光合指标(单株叶面积、SPAD、净光合速率)、干物质积累量均呈先升后降的趋势,于1.00%处理达到最大,叶片干物质分配比例、转运量、转运率和贡献率均明显提高,而茎秆和根系的转运率和贡献率下降;当添加量达4.00%时,光合各指标和干物质积累量低于对照,辣椒茎秆干物质分配比例提高,转运量、转运率和贡献率无明显提高,而叶片转运量、转运率和贡献率均下降,说明镁元素高添加量对辣椒叶片光合有抑制作用,不利于辣椒进行光合作用,且改变了植株干物质的分配与转运,不利于干物质从营养器官向生殖器官中转化。综上,在0~2.00%范围内,镁元素添加提高了辣椒的光合性能,优化了辣椒干物质的积累与分配,其中以1.00%处理效果最好,4.00%对辣椒的光合性能产生抑制作用,不利于辣椒干物质积累与分配,进而影响产量提高。     

昼夜温差对番茄果期干物质分配的影响及模拟

以番茄品种"金冠5号"为试材,在人工气候箱对坐果后的番茄植株进行昼夜温差(DIF)处理,设置25℃日平均温度下5个昼夜温差水平,即-18℃(16/34,昼温/夜温,℃,以下同)、-12℃(19/31)、0℃(25/25)、+12℃(31/19)、+18℃(34/16),研究昼夜温差对番茄干物质分配在果期各阶段的影响,并构建综合了昼夜温差、辐射和热效应的干物质分配动态模拟模型。结果表明:与零昼夜温差处理相比,+12℃DIF使根和叶的干物质分配比例降低,茎和果实的干物质分配比例增加;+18℃DIF使叶干物质分配比例增加,而使果实干物质分配比例减少。而负昼夜温差使根、叶的干物质分配比例增加,茎、果实的干物质分配比例降低。不同昼夜温差处理下,根、茎、叶的干物质分配比例均与坐果后的累积辐热积呈指数递减关系,而果实的干物质分配比例与坐果后的累积辐热积呈Logistic模型递增关系,通过拟合昼夜温差值与指数模型和Logistic模型参数的数量关系,得到昼夜温差对根、茎、叶、果的干物质分配比例影响的模拟模型。经独立试验数据检验表明,模拟效果良好。     

向日葵干物质积累及分配特点研究

采用田间试验与测试分析相结合的方法,分别在宁夏固原、盐池等地设置了食用葵和油用葵干物质测定试验,研究了在施肥与不施肥条件下向日葵不同生育期干物质积累特点。结果表明:食用葵和油用葵在施肥与不施肥情况下,向日葵干物质积累量随生长发育均呈"S"型趋势,这一趋势可用Logistic方程模拟;且油用葵和食用葵的干物质累积比例在苗期均为叶片茎秆根,现蕾期为茎秆叶片根花盘,开花期为茎秆叶片花盘根,成熟期为茎秆籽实花盘叶片根,且干物质含量随生育期延长呈增加态势;合理施肥能明显增加向日葵干物质积累量,食用葵施肥处理干物质总累积量较不施肥处理增加53.70%,油用葵施肥处理干物质总累积量较不施肥处理增加59.18%;食用葵干物质总累积量与油用葵相比,差异不显著。     

不同氮水平下的日光温室茄子干物质积累模型

以‘茄杂2号’为试材，以滴灌节水灌溉制度为基础，设置5个不同施氮水平处理，并综合温度和光合辐射对茄子生长的影响，建立了基于辐热积的日光温室茄子干物质积累模拟模型，以期为日光温室茄子生产的光温环境调控提供参考依据。结果表明：模型对F1～F5处理日光温室茄子全株干物质积累量的实测值与模拟值的RMSE为61.41～135.37 kg·hm^-2,1∶1直线之间的R²为0.997 2～0.999 6;模型对茄子茎干物质积累量的实测值与模拟值的RMSE为60.10～65.62 kg·hm^-2,1∶1直线之间的R²为0.973 2～0.988 3;叶干物质积累量的实测值与模拟值的RMSE分别为57.50～122.28 kg·hm^-2,1∶1直线之间的R²为0.977 5～0.991 0;果干物质积累量的实测值与模拟值的RMSE为134.21～162.02 kg·hm^-2,1∶1直线之间的R²为0.982 6～0.991 2。模...     

水分胁迫对‘赤霞珠’不同叶龄叶片光合特性的影响

【目的】探究水分胁迫对葡萄不同叶龄叶片光合及荧光变化规律的影响。【方法】以3 a(年)生‘赤霞珠’葡萄(Vitis vinifera‘Cabernet Sauvignon’)为试材,由黎明前叶片水势(ψb)反映胁迫程度,设置对照(无水分胁迫,CK)、中度水分胁迫(T1)和重度水分胁迫(T2)三个处理,测定‘赤霞珠’葡萄新梢不同叶龄叶面积、叶片光合参数、叶绿素荧光参数及Ru BP活化酶和果糖-1,6-二磷酸酯酶活性。【结果】葡萄叶片叶龄为80 d时,叶面积趋于稳定,T2显著降低了各叶龄叶片的面积,T1与CK无显著性差异;葡萄叶片SPAD值随叶龄的增加而增大,且T1增加了各叶龄叶片SPAD值,T2则降低;Pn、Gs、Tr、Ru BP活化酶和果糖-1,6-二磷酸酯酶活性随葡萄叶片叶龄的增加均呈先上升后下降的趋势,并且随水分胁迫程度的增加下降程度增大;水分胁迫不同程度地降低了各叶龄叶片Fv/Fm、Yield、ETR、q P,而Fo显著增加,T2增加了各叶龄叶片的NPQ,但随着叶龄的增加,T2叶片NPQ又显著低于其他两个处理。【结论】随‘赤霞珠’葡萄叶片叶龄的增加,光合能力呈先上升后下降的趋势,当葡萄叶片叶龄为60~90 d时,光合能力最强。水分胁迫降低了各叶龄叶片的光合效率,重度水分胁迫会阻碍葡萄幼龄叶片的正常发育,并加速老龄叶片的衰老。     

T337自根砧富士苹果幼树氮含量与积累量年周期变化

以3年生T337自根砧富士苹果幼树为试材,年生长周期内定期整株取样,并将整树解析为主根木质部、主根韧皮部、细根、砧木木质部、砧木韧皮部、主干木质部、主干韧皮部、叶片、新梢9部分,分别测定各部位不同时期的生物量和N含量。结果表明,T337自根砧富士苹果幼树各时期各部位N含量为叶片最高,新梢、细根、韧皮部相对较高,而木质部最低。树体各器官干物质和N分配量、分配比率均为营养器官叶片、新梢和细根高于贮藏器官木质部和韧皮部。总干物质与N积累量均为生长后期较高,定植后30~120 d树体干物质积累量占总积累量31.46%,120~180 d树体干物质积累量占68.54%;定植后30~90 d树体N积累量占总积累量37.65%,90~120 d占13.48%,120~180 d占48.87%。     

地方柑橘良种（贡柑）新建果园土壤和树体养分分布特征

测定、分析广东省肇庆地区五和镇新建贡柑果园土壤养分、树体矿质元素含量及分布特征和相关性。结果表明：供试果园土壤pH值偏低,有机质含量中等偏低,土壤缺乏交换性钙、交换性镁和有效硼等元素。叶片中矿质元素含量与土壤养分之间有一定的相关性,春梢和秋梢叶片中不同矿质元素含量分布规律不同,并受土壤相关元素丰缺度、矿质元素在树体内的分配与再分配特性等因素的影响。     

水分胁迫对'赤霞珠'葡萄不同叶龄叶片糖含量及相关代谢酶活性的影响

以三年生'赤霞珠'葡萄为试材,通过控制灌溉量,以黎明前叶片水势(ψb)反映胁迫程度,设置无水分胁迫、中度水分胁迫和重度水分胁迫3个处理,研究了'赤霞珠'葡萄新梢基部(叶1)、下部(叶2)、中部(叶3)、中上部(叶4)、上部(叶5)叶片的糖含量及其相关代谢酶活性,以期明确水分胁迫对'赤霞珠'葡萄不同叶龄叶片糖含量及其相关代谢酶活性的影响.结果 表明:中度水分胁迫处理下,葡萄新梢不同叶龄叶片蔗糖、可溶性糖含量均高于对照组,处理前期还原糖含量低于对照组;处理中后期还原糖含量高于对照组;重度水分胁迫处理下,葡萄新梢不同叶龄叶片蔗糖含量低于对照组、还原糖含量高于对照组;在处理前期,叶3～5可溶性糖含量高于对照组,后期各叶龄叶片可溶性糖含量逐渐低于对照组;中度水分胁迫可以提高叶3～5叶片蔗糖磷酸合成酶(SPS)活性,而重度水分胁迫降低了不同叶龄叶片蔗糖磷酸合成酶(SPS);水分胁迫可以提高叶3～5叶片中性转化酶(NI)活性、不同叶龄叶片蔗糖合成酶(SS)和酸性转化酶(AI)活性;中度水分胁迫有利于不同叶龄叶片糖分的积累及相关代谢酶活性的提高.     

柴达木地区枸杞干物质积累及养分吸收特性研究

以青海省柴达木地区目前栽培较广的"宁杞5号"为研究对象,研究滴灌施肥条件枸杞干物质积累、枸杞产量与氮磷钾含量、氮磷钾积累量的变化规律。结果表明:枸杞全生育期干物质累积量呈"S型"曲线变化,在盛果期至秋果期干物质积累达到最高峰,叶片在不同时期总干物质积累量中的比例在77.5%~6.64%变化。柴达木地区枸杞养分主要限制因子为氮,其次为钾和磷,且养分吸收高峰出现在8月下旬的盛果期。每生产100kg枸杞干果养分的需求量平均为N 11.2kg、P2O52.2kg、K2O 6.7kg。当年新生油条是氮、磷、钾养分的优先分配部位。     

不同光质对丰香草莓生长发育的影响

研究了相同光强下不同光质对丰香草莓生长发育的影响。结果表明,不同光质膜处理对草莓的生长结果、干物质分配和果实品质均有影响。与中性膜相比,绿膜和红膜下草莓植株的叶柄长度和叶面积显著增加,而蓝膜的叶柄长度和叶面积明显较低。光质不同也影响草莓干物质的分配,干物质向叶片和叶柄分配比例绿膜最高,蓝膜最低,其它膜之间相近。而干物质向果实、冠状茎和根系中的分配比例均以蓝膜最高,其次为红膜,绿膜最低,黄膜与中性膜相近。红膜下生长的草莓,产量最高、果实最大;蓝膜下可溶性固形物含量、抗坏血酸含量和固酸比最高;而绿膜下则产量最低、果实最小、可溶性固形物含量和固酸比最低。抗坏血酸含量的高低与不同膜中的紫外和蓝紫光的比例一致,与红光/蓝光比值相反。     

温室小型西瓜光合生产与干物质积累模拟模型

在借鉴国内外温室蔬菜作物光合生产和干物质积累模拟模型的基础上,根据温室小型西瓜的试验数据,确 定有关模型参数,建立了温室小型西瓜光合生产和干物质积累模拟模型,模型包括叶面积指数动态模型、光合生产 动态模型和干物质积累动态模型。模型利用有效积温对叶面积指数LOGISTIC方程建立叶面积指数动态模型,同时 光合作用模型还引用简便有效的高斯积分法计算冠层每日的总同化量,既考虑了光合有效辐射的日变化规律,又考 虑了太阳高度角的变化对冠层反射率的影响;此外,模型还考虑了温度对呼吸作用的影响,确定了温室小型西瓜的 碳水化合物转化成干物质的系数CF。通过不同品种、不同播期下的干物质积累动态的模型检验,表明模型有较强的 精确性、机理性和实用性。     

温室甜瓜光合生产与干物质积累模拟模型研究

在借鉴国内外温室蔬菜作物光合生产和干物质积累模拟模型的基础上,根据温室甜瓜的试验数据,确定有关模型参数,建立了温室甜瓜光合生产与干物质积累模拟模型,模型包括叶面积指数、光合生产及干物质积累动态模型。模型利用比叶面积法建立了叶面积指数动态模型,光合作用模型还引用简便有效的高斯积分法计算冠层每日的总同化量,不但考虑了光合有效辐射的日变化规律,而且考虑了太阳高度角的变化对冠层反射率的影响和温度对呼吸作用的影响。通过不同品种干物质积累动态模型检验表明,模型机理性、通用性和精度较好。     

日光温室不同矮蔓型西葫芦的干物质生产与分配研究

对4个不同矮蔓型西葫芦品种的干物质生产与分配进行研究,结果表明,半矮蔓与矮蔓西葫芦品种各器官干物质含量没有显著差异,根、茎、叶、果干物质含量分别为:9%、6%、12%、5%;全生育期群体生长率(cropgrowth rate,CGR)半矮蔓品种平均为17.2g/(m2·d),而矮蔓品种为12.5g/(m2·d),半矮蔓品种是矮蔓品种的1.38倍;苗期、结果初期、结果中期、结果后期的当前干物质生产量半矮蔓品种分别是矮蔓品种的1.07、1.28、1.26、1.91倍,后期干物质生产衰减与矮蔓品种的早衰存在着相互依存关系;当前干物质的分配率营养器官与生殖器官的比半矮蔓品种为2.7∶1,矮蔓品种为2.1∶1;干物质累积值半矮蔓品种是矮蔓品种的1.4倍,果实干质量累积值半矮蔓品种是矮蔓品种的1.27倍,半矮蔓品种干物质向果实的分配率约为30.8%,矮蔓品种约为34.7%,单位面积干物质生产量的提高是半矮蔓品种果实干质量高于矮蔓品种的主要原因。     

Modelling the effects of soil water potential on growth and quality of cut chrysanthemum (Chrysanthemum morifolium)

A complete dynamic model was developed to describe the effects of soil water potential (WP) on the growth and external quality of standard cut chrysanthemum (Chrysanthemum morifolium) in order to optimise water management of greenhouse crops. Experiments using chrysanthemum cv. ‘Jinba’ with different planting dates and levels of water treatment were conducted in a lean-to type greenhouse from 2006 to 2008. The dynamics of leaf area index (LAI), dry matter partitioning, and external quality traits (plant height, number of leaves per plant, flower-head diameter and peduncle length) were first determined as functions of accumulated photothermal index (PTI). Impacts of WP on leaf photosynthetic rate, LAI, dry matter partitioning, and the external quality traits were quantified via introducing the experimentally identified effects of WP on the parameters in the light response curve of leaf photosynthetic rate and the PTI-based functions. These quantitative relationships were incorporated into a generic crop growth model SUCROS. Using independent experimental data, the model was found to give good predictions for biomass production, dry weight of organs, and the external quality traits of the chrysanthemum cultivar grown under different levels of water supply. The coefficient of determination (r²) between the predicted and measured results was 0.91 for LAI, 0.88 for biomass production, and varied between 0.83 and 0.93 for organ dry weight and the external quality traits. Further evaluation is needed when applying this model to a wider range.     

Influence of fruit load on dry matter and N-distribution in sweet pepper plants

The influence of fruit load on the leaf characteristics and on the distribution of dry matter (DM) and nitrogen (N) in sweet pepper (Capsicum annuum L., cv. Cornado) plants was investigated under Mediterranean glasshouse conditions during a winter–spring production cycle (from December till June). DM weight of all organs (roots, stems + petioles, leaves and fruits) and N content were determined throughout the growing cycle over a 3-week interval. The results showed that the cyclic fruit load pattern (production flushes) was associated with strong variations of N-leaf content on an area basis and specific leaf weight, SLW. On a whole plant scale, the value of SLW dramatically decreased (≈30%) with increasing fruit load; the reverse held true as long as the fruit dry weight remained low (<30 g pl⁻¹). The decline in SLW was coincident with a shift in distribution of DM and N in the plant, both preferentially diverted to the fruits. The time evolution of DM and N fractions in organs exhibited periodic fluctuations, with a duration close to the length of a fruit growth cycle (about 70 days, from anthesis to harvest). Linear relationships were found between the fraction of dry mass and N in fruits, and those of the other organs. The slope of these relationships was considered as an indicator of the response and sensitivity of the organ growth to an increase in fruit load. The root dry mass fraction was the most affected by increases in fruit load (slope of −0.75), while the N fraction in roots and in leaves was affected to a similar extent (slope of −0.50 and of −0.40, respectively). We conclude that, in the sweet pepper, the cyclic pattern of fruit load induces opposite cyclic patterns of dry matter and N content in the other aerial organs as well as in the roots, thereby reflecting close shoot–root coordination in the allocation of carbon and nitrogen resources among the organs. Finally, we discuss the possible implications that could derive from these findings for modelling dry matter partitioning in plants subjected to continuous fruit harvesting.     

Effect of the amount and position of leaf tissue on the yield of single-truss tomatoes

Immediately after first anthesis, leaf removal treatments were applied, involving varying amounts of leaf tissue at different positions on the stem of widely spaced single-truss tomato plants.Yield was shown to be related to leaf dry weight, while leaf position did not appear to be important, except for those leaves closest to the roots. The leaves and roots were shown to be in competition with the reproductive tissues for dry matter.     

Dry-matter production in a tomato crop: comparison of two simulation models

TOMSIM(l.O) and TOMGRO(l.O) are two dynamic models for tomato growth and development. Their submodels for dry matter production are compared and discussed. In TOMSIM(l.O), dry matter production is simulated by a modified version of SUCROS87 (Spitters et al., 1989). Single leaf photosynthesis rates are calculated separately for shaded and sunlit leaf area at different depths in the canopy, according to the direct and diffuse components of light; daily crop gross assimilation rate (A) is computed by integration of these rates over the different depths and over the day. In TOMSIM(l.O) leaf photochemical efficiency (e) and potential leaf gross photosynthesis rate at saturating light level (Pgmax) both depend on temperature and C02 level. In TOMGRO(l.O) crop gross photosynthesis rate is calculated by the equation of Acock et al. (1978); e is a constant and Pg max is a linear function of C02. In both models leaf photosynthesis characteristics are assumed to be identical in the whole canopy. Maintenance respiration (Rm) and conversion efficiency (Cf) are taken into account in the same way, except that root maintenance respiration is neglected in TOMGRO(l.O). For both models a sensitivity analysis was performed on the input variables (light intensity, temperature, C02 and leaf area index (LAI)) and on some of the model parameters. Under most conditions considered, simulated A was found to be 5-30% higher in TOMSIM(l.O) than in TOMGRO(l.O). At temperatures above 18°C Rm was also higher in TOMSIM(l.O), and C, was 4% higher in TOMGRO(l.O). The two models were very sensitive to changes in e and to a lesser extent to changes in the light extinction coefficient, whereas the scattering coefficient of leaves had hardly any effect on the simulated A. TOMGRO(l.O) appeared to be rather sensitive to the C02 use efficiency, whereas at ambient C02 level mesophyll resistance was quite important in TOMSIM(l.O). Four sets of experimental data (differences in cultivar, C02 enrichment and planting date) from Wageningen (The Netherlands) and Montfavet (southern France) were used to validate the models. Average 24 h temperature and average daily C02 concentration values were used as input to the models. For the Wageningen experiments, hourly PAR values were calculated from the daily global radiation sum by TOMSIM(l.O) and used as input in both models. For the Montfavet experiment, average hourly PAR measurements were used. Also measured LAI, dry matter distribution and organ dry weights (for calculation of Rm) were input to the simulation. In the Wageningen experiments, total dry matter production was simulated reasonably well by both models, whereas in the Montfavet experiment an under-estimation of about 35% occurred. TOMGRO(l.O) and TOMSIM(l.O) simulated almost identical curves in all four experiments. Strong and weak points of both models are discussed.     

The effect of intracanopy lighting on cucumber fruit yield—Model analysis

Intracanopy lighting is a recently developed supplementary lighting technique for high-wire grown vegetable production in greenhouses where a part of the lamps is mounted within instead of above the canopy. A potentially higher yield using intracanopy lighting compared with top-lighting, is based on three assumptions: (1) increased light-absorption by the crop; (2) a higher photosynthetic light use efficiency due to a more homogeneous vertical light distribution; (3) a preserved photosynthetic capacity of leaves deeper in the canopy. We used an explanatory crop model to quantify the relative importance of these assumptions for a cucumber crop during an experiment in winter in the Netherlands (Trouwborst et al., 2010). Photosynthesis and yield data of this intracanopy lighting experiment with light-emitting diodes (34% of supplemental PAR) in combination with top-lighting (66% of supplemental PAR) were used to parameterise our model. In that study intracanopy lighting did not result in an increased yield compared with 100% top-lighting due to extreme leaf curling and a lower dry matter partitioning to the fruits. Our model predicted an 8% increase in fruit yield for the intracanopy lighting treatment if there were to be no leaf curling and no lower dry matter partitioning. This increase can be largely explained by the change in light distribution and light absorption. The model further revealed unexpectedly large consequences of the lower dry matter partitioning to the fruits whereas the negative effect of leaf curling was small. The direct effect of a greater A_max at deeper canopy layers was slightly positive. The last however might have indirectly caused the greater partitioning to the leaves as the greater A_max was associated with a preserved leaf mass per area. Solutions for this problem are discussed. Our explanatory model allowed us to disentangle the interacting effects of intracanopy lighting on fruit yield. Overall, intracanopy lighting has been shown here to potentially increase the assimilation light use efficiency.     

Plant density in relation to tulip bulb growth

Field experiments were performed with tulips (‘Merry Widow’, size 8 to 9 cm, type A) to study the effects of plant density on dry matter production, bulb production, leaf formation and stem development. Dry matter production proved to be linearly related to the degree of soil coverage, and was 256 kg · ha^?1 · day^?1 at 100% soil coverage. leaf area was independent of plant density, but leaf and stem sizes reacted sharply.A graphic model for the effect of leaf area per plant on the reaction of daily production to plant density is given.     

同步叶片修剪对温室番茄干物质优化分配的影响

 研究了同步叶片修剪对温室番茄品种‘Capita’干物质优化分配的影响。结果表明, 在每穗果实数修剪为6个时, 一方面会减少营养生长库强, 显著降低了叶面积指数(LA I) 和植株总干质量; 另一方面有利于干物质分配到果实, 显著提高果实累积干物质分配率, 补偿因植株总干质量降低而引起的果实干质量的降低。在合理增加植株密度时, 同步叶片修剪可以显著提高LA I与单位面积植株总干质量, 从而显著提高单位面积果实干质量。