棉花生长发育模拟模型的研究

本文是根据1984—1985年大田资料建立的一个棉花生长发育模型。模型利用光能辐射,叶面积指数,植株干重等来计算净光合产物,并在各器官之间进行分配。利用生理学时间来预测主茎节数,根据顶芽、腋芽分化的同步序列,来确定果枝数、果节数。单铃重随其生理时间而呈逻辑斯谛克曲线分布: BW=8.2842/(1+e5.2701-0.0073×PT) 并定出蕾铃潜在增长率,根据潜在增长率求出每米~2土地上蕾铃干物质需求量,从营养供求状况来控制雷铃脱落。 根据模型预测,可确定棉花不同生育时期最佳栽培措施;与棉虫动态模型偶联,可研究棉虫动态经济阈值。     

基于冠层温湿度模型的日光温室黄瓜霜霉病预警方法

利用温室环境参数构建室内微环境模拟模型,并结合温室病害模型进行预警,便于开展病害生态防治,以减少农药使用,从而保护温室生态环境和保证农产品质量安全.本文利用温室内能量守恒原理和水分平衡原理,构建了日光温室冠层叶片温度和空气相对湿度模拟模型.叶片温度模拟模型考虑了温室内植物与墙体、土壤、覆盖物之间的辐射热交换,以及室内净辐射、叶片蒸腾作用引起的能量变化;相对湿度模拟模型综合了温室内叶片蒸腾、土壤蒸发、覆盖物与叶面的水汽凝结引起的水分变化.将温湿度估计模型输出值作为参数,输入黄瓜霜霉病初侵染和潜育期预警模型中,估计黄瓜霜霉病发病日期,并与田间观测的实际发病日期比较.试验选取2014年9月和10月的温湿度监测数据进行模型验证,冠层叶片温度实际值与模拟值的均方根偏差（RMSD)分别为0.016和0.024 ℃,空气相对湿度实际值与模拟值的RMSD分别为0.15%和0.13%.结合温湿度估计模型结果表明,黄瓜病害预警系统预测黄瓜霜霉病发病日期与田间调查发病日期相吻合.本研究可为黄瓜日光温室病害预警模型及系统构建提供微环境数据支持.     

灌溉水稻生长发育和潜力产量的模拟模型

本文提出的HDRICE模型是灌溉水稻生长的生理生态模型,它由相互衍接的水稻形态发育、干物质积累和叶面积发育三模块组成。形态发育模块用以模拟逐日温度和日长对水稻发育的影响,其参数可反映水稻品种的基本营养性、感温性和感光性;干物质积累模块用以模拟冠层CO_2同化、作物的维持呼吸和生长呼吸及干物质分配等过程;叶面积发育模块用以模拟叶面积指数的动态。本文还讨论了模型的输入参数和模型检验。模型可应用于模拟水稻的生长发育,预测水稻品种潜在产量及为取得潜在产量所必需的群体数量指标。     

日光温室地面覆盖对嫁接与未嫁接黄瓜生长发育、产量及土壤环境的影响

研究了秸秆、地膜和秸秆+地膜覆盖对日光温室嫁接与未嫁接黄瓜生长发育、产量及土壤环境的影响.结果表明,地面覆盖不仅能促进雌花分化、缩短成瓜时间、增加单瓜重、提高黄瓜产量,而且能降低畸形瓜比例,提高产品的商品性.其中以覆盖秸秆+地膜作用最明显、增产幅度最大,覆盖秸秆和覆盖地膜次之;嫁接黄瓜的处理效果优于未嫁接黄瓜.此外,地面覆盖对土壤环境也具有重要影响,但不同处理之间差异较大.地温日变化呈单峰曲线, 5cm、10 cm地温的波峰出现在14:30,随着土层的加深而波峰推迟出现,峰值也逐渐减小.秸秆覆盖具有降低最高地温和提高最低地温的作用,使土壤温度保持相对稳定;地膜覆盖对最高地温的增幅最大、对最低地温的增幅最小,从而使地温变幅最大;秸秆+地膜覆盖既增温又保温.地面覆盖的土壤呼吸速率均显著高于对照(P＜0.01),并以秸秆+地膜覆盖的土壤呼吸速率最高,地膜覆盖与秸秆覆盖次之,土壤呼吸速率日变化也呈单峰曲线,与 5cm、10 cm地温日变化趋势一致,峰值出现在14:30左右,土壤呼吸速率与 5cm、10 cm地温达显著或极显著相关.秸秆覆盖与秸秆+地膜覆盖的0～20 cm土层土壤容重显著小于地膜覆盖与对照(P＜0.01),地膜覆盖的土壤容重略小于对照,随着土层的加深,各处理间土壤容重差异渐小.     

基于生理发育时间的日光温室茄子发育模拟模型

本研究将温度对茄子发育速率影响效应的大小用相对热效应(RTE)来衡量,通过研究Beta函数的性质提出基于幂函数的模型来描述RTE与温度之间的关系.采用生理发育时间(Physiological Development'Time,PDT)作为定量发育进程的尺度,建立了温室茄子发育模拟模型.利用模型对日光温室2年3茬茄子生长发育期资料进行检验的结果表明:模型能较好地预测各个发育期(发芽、苗期、开花座果、结果和采收期)的出现时间和持续时间,各生育期模拟值与观测值的回归估计标准误差(RMSE)分别为1.0d,1.73d,0.82d,1.41d,2.38d,显著优于以有效积温模拟模型的预测精度(其生育期模拟的RMSE分别为2.38d,7.14d,1.73d,5.07d,8.25d).     

大棚番茄生长发育与棉铃虫危害的模拟模型研究

根据１９９３～１９９４年大田资料建立了塑料大棚番茄的生长发育动态模型和棉铃虫Ｈｅｌｉｃｏｖｅｒｐａａｒｍｉｇｅｒｚａ（Ｈｕｂｎｅｒ）取食为害模型,动态模拟了番茄的净光合产量和各器官的干物质消长,以及植株的形态建成和产量形成过程,模型把番茄繁殖器官的脱落按其成因归纳为生理的,环境的及病虫害引起的脱落,容量包棉铃虫取食为害模型偶联,棉铃虫对番茄的取食为害模型为第一代,第二代棉铃虫取食不同时期番茄各发育     

日光温室栽培对杏花及果实生长发育的影响

对日光温室内与露地栽培的金太阳杏的花期物候、花型及果实生长发育进行了系统观察与分析,结果表明,日光温室栽培比露地栽培的始花期提前33d,花期延长4d,不完全花比例上升33.25%;果枝上花的有效性顺序由露地时的中果枝>长果枝>短果枝>花束状果枝变为温室栽培的短果枝>花束状果枝>中果枝>长果枝;日光温室栽培使杏果实发育的第 、 阶段延长,第 阶段缩短,整个生育期延长15d。统计分析认为:日光温室栽培的第 阶段生长速率显著低于露地,第 阶段的累积生长量显著高于露地。较低的夜间温度是造成温室内杏果实第 阶段较长、生长较慢以及果个变大的原因。     

乌兰布和沙区紫花苜蓿生长发育模拟研究

借鉴积温学的原理,结合紫花苜蓿（Meicago sativa)生理生态学特性,建立了水分限制条件下干旱沙区紫花苜蓿生长发育模拟模型,该模型主要由生长发育阶段子模型,叶面积动态子模型,干物质积累子模型和干物质分配子模型组成。模拟计算结果表明,该模型能较好地预测沙地紫花苜蓿生长发育进程,叶面积变化动态及牧草产量变化动态,具有一定的实际应用价值。     

日光温室连作土壤酚类物质变化及其对黄瓜根系

研究了日光温室连作黄瓜土壤酚类物质变化及其对黄瓜根系抗病性相关酶的影响.结果表明,随着连作年限的增加,对羟基苯甲酸、阿魏酸、苯甲酸以及总量呈现明显的积累特征:种植5年、7年、9年的含量显著高于1年、3年,且9年的是1年的2倍.在低浓度处理下(40和80 μg·g^-1),前期（2、3叶期）诱导多酚氧化酶、过氧化物酶、苯丙氨酸转氨酶活性不同程度地升高,植株表现高抗性,在较高浓度下(120和160 μg·g^-1),处理前期多酚氧化酶、过氧化物酶、苯丙氨酸转氨酶活性迅速降低,甚至丧失酶活性.连作土壤酚类物质浓度变化是影响日光温室黄瓜抗病性的主要因素之一.     

日光温室不同连作年限对黄瓜生理特性的影响

在日光温室条件下,研究了不同连作年限土壤对黄瓜生理特性的影响。结果表明,不同连作年限土壤对黄瓜光合速率、植株生长特性和产量均有极为显著的影响。在开始种植黄瓜的几年内,黄瓜的光合速率、株高、叶片数和生产力均维持在较高水平;随着连作年限延长,黄瓜的光合速率、株高、叶片数和产量明显降低;连作4a以后,黄瓜的生理障碍开始有明显表现。     

施肥对日光温室黄瓜生长和土壤生物学特性的影响

采用田间试验研究了施肥对黄土高原日光温室黄瓜生长发育和产量,以及对土壤微生物区系和土壤酶活性的影响。结果表明,施用有机肥和沼肥明显促进了黄瓜生长发育,提高了黄瓜产量,叶面施肥可以降低无机化肥和有机肥用量,施肥对日光温室土壤生物学特性有明显影响,施用有机肥和叶面施肥增加了土壤细菌数量;施用无机化肥和沼肥增加了真菌的数量,施用有机肥降低了真菌的数量;施肥增加了放线菌的数量．同时施肥提高了土壤脲酶、磷酸酶、蔗糖酶活性,但对过氧化氢酶影响较小．施用有机肥提高了脲酶和磷酸酶活性,施用化肥和沼肥对土壤脲酶和土壤磷酸酶活性影响差异不大。     

日光温室光温因子对黄瓜叶绿体超微结构及其功能的影响

在日光温室内,研究了光温因子对黄瓜叶绿体超微结构及其功能的影响．结果表明,因季节之间光、温条件不同,日光温室黄瓜叶片显微结构和叶绿体超微结构有一定差异,1月份光照弱叶肉细胞较大,而5月份光照强叶绿体数较多．在该试验条件下,未发现叶片光合速率与叶绿体超微结构之间有直接或密切的相关性．在各生长季节其光合速率均为第4叶>初展叶>基部叶,与叶龄及各叶位的受光量有关．如果将不同叶位叶放在相同的光照下,则差异明显减少．黄瓜叶片的叶肉细胞、叶绿体和淀粉粒的大小以及叶绿体数、基粒数、基粒厚度、基粒片层数都随叶位的下降而呈增加趋势。不同品种、同品种不同生长时期的叶片显微结构和叶绿体超微结构及其功能也有一定的差异．限制日光温室冬季黄瓜光合作用的主要因素是光照弱、有效光照时数少,而在晴天温度的限制作用相对较小。阴天因光照弱而导致的室内低温则是限制黄瓜生长的关键因素．     

施肥对日光温室土壤硝酸盐分布特征的影响

在陕北延安研究了施肥对日光温室土壤硝酸盐分布的影响。结果表明,日光温室土壤的NO3^--N的动态分布与剖面淋洗深度与施肥关系密切,施用化肥、有机肥和沼肥都会导致土壤剖面的NO3^--N累积。而累积时期与黄瓜的生长发育过程有关,在黄瓜的生长前期和后期,土壤的NO3^--N高,易出现NO3^--N累积和淋洗;生长中期,土壤的NO3^--N含量低,不会出现NO3^--N累积和淋洗。0～20cm和20～40cm土层的土壤氮索对黄瓜生长都有效。     

日光温室渗灌效果研究

对日光温室渗灌和沟灌的土壤环境,室内空气环境,作物生育及病毒状况,水分利用效率等进行了研究,结果表明,与沟灌相比,渗灌可增加土壤水稳定性团粒81．4％,降低土壤容重21．2％,增加土壤孔隙度29．0％,提高土壤温度1．1－1．7℃,降低空气湿度13．4％,节约灌溉用水36．7％,而且能促使作物早熟,提高作物产量,减少作物病害,降低生产成本,是目前日光温室理想的灌溉技术。     

Simplification of a light-based model for estimating final internode length in greenhouse cucumber canopies

Background and Aims

Light quantity and quality affect internode lengths in cucumber (Cucumis sativus), whereby leaf area and the optical properties of the leaves mainly control light quality within a cucumber plant community. This modelling study aimed at providing a simple, non-destructive method to predict final internode lengths (FILs) using light quantity and leaf area data.

Methods

Several simplifications of a light quantity and quality sensitive model for estimating FILs in cucumber have been tested. The direct simplifications substitute the term for the red : far-red (R : FR) ratios, by a term for (a) the leaf area index (LAI, m² m⁻²) or (b) partial LAI, the cumulative leaf area per m² ground, where leaf area per m² ground is accumulated from the top of each plant until a number, n, of leaves per plant is reached. The indirect simplifications estimate the input R : FR ratio based on partial leaf area and plant density.

Key Results

In all models, simulated FILs were in line with the measured FILs over various canopy architectures and light conditions, but the prediction quality varied. The indirect simplification based on leaf area of ten leaves revealed the best fit with measured data. Its prediction quality was even higher than of the original model.

Conclusions

This study showed that for vertically trained cucumber plants, leaf area data can substitute local light quality data for estimating FIL data. In unstressed canopies, leaf area over the upper ten ranks seems to represent the feedback of the growing architecture on internode elongation with respect to light quality. This highlights the role of this domain of leaves as the primary source for the specific R : FR signal controlling the final length of an internode and could therefore guide future research on up-scaling local processes to the crop level.     

Dry matter partitioning models for the simulation of individual fruit growth in greenhouse cucumber canopies

Background and Aims

Growth imbalances between individual fruits are common in indeterminate plants such as cucumber (Cucumis sativus). In this species, these imbalances can be related to differences in two growth characteristics, fruit growth duration until reaching a given size and fruit abortion. Both are related to distribution, and environmental factors as well as canopy architecture play a key role in their differentiation. Furthermore, events leading to a fruit reaching its harvestable size before or simultaneously with a prior fruit can be observed. Functional–structural plant models (FSPMs) allow for interactions between environmental factors, canopy architecture and physiological processes. Here, we tested hypotheses which account for these interactions by introducing dominance and abortion thresholds for the partitioning of assimilates between growing fruits.

Methods

Using the L-System formalism, an FSPM was developed which combined a model for architectural development, a biochemical model of photosynthesis and a model for assimilate partitioning, the last including a fruit growth model based on a size-related potential growth rate (R_P). Starting from a distribution proportional to R_P, the model was extended by including abortion and dominance. Abortion was related to source strength and dominance to sink strength. Both thresholds were varied to test their influence on fruit growth characteristics. Simulations were conducted for a dense row and a sparse isometric canopy.

Key Results

The simple partitioning models failed to simulate individual fruit growth realistically. The introduction of abortion and dominance thresholds gave the best results. Simulations of fruit growth durations and abortion rates were in line with measurements, and events in which a fruit was harvestable earlier than an older fruit were reproduced.

Conclusions

Dominance and abortion events need to be considered when simulating typical fruit growth traits. By integrating environmental factors, the FSPM can be a valuable tool to analyse and improve existing knowledge about the dynamics of assimilates partitioning.     

温室黄瓜叶部微生物区系

采用稀释分离法和消毒叶片研磨液培养法对温室黄瓜叶围和内生微生物进行了分离,共分离到248个菌株,初步鉴定出13个属的叶围真菌,其中链格孢属(Alternaria)和青霉属(Penicillium)真菌为优势类群;鉴定出4个属的内生真菌,其中曲霉属(Aspergillus)真菌为优势类群;10个属的叶围细菌,其中芽孢杆菌属(Bacillus)和黄单胞菌属(Xanthomonas)细菌为优势类群;6个属的内生细菌,其中芽孢杆菌属和假单胞菌属(Pseudomonas)细菌为优势类群;6个属的叶围酵母菌,其中隐球酵母属(Cryptococcus)为优势类群;已鉴定出2个属的叶围放线菌,分别为链霉菌属(Streptomyces)和小多孢菌属(Micropolpspora).未分离到内生酵母菌和放线菌.     

The influence of thermoperiod on cucumber growth and development

We studied the influence of gradient temperature regimes on various parameters of the formation of above-the-ground and underground organs of cucumber plants, such as rate of leaf appearance, rate of growth, duration of growth and length of leaves, and the rate of growth of above-the-ground organs and roots. The plants were grown under the controlled conditions: at different combinations of day and night temperature, illumination 100 Wt/m2, and 12 h photoperiod. The comparison of constant and fluctuating diurnal temperature regimes has shown that in the optimal area for all studied indices, the highest values were recorded at the constant daily temperature (25 degrees C for all growth indices of above-the-ground organs and 20 degrees C for growth of roots), while all gradient regimes either did not affect, or exerted inhibitory effects on the plant. The main acting fluctuating temperatures, that exerted stimulating effects, combined low hardening (15 degrees C) and optimal temperatures (25 degrees C), which was earlier described for animals. The 15/35 and 35/15 degrees C combinations were unambiguously inhibitory, since both temperatures are hardening for the cucumber. A lesser stimulating effect of the developmental rate in a plant, as compared to poikilothermic animals, could be due to a greater autonomy of plant ontogenesis because of autotrophy and, correspondingly, a greater degree of homeostasis. The mechanisms accounting for the reactions to temperature gradients are similar in different groups of ectotherms.     

Optimal temperature drop for the growth and development of young cucumber plants

The thermomorphological responses of young cucumber plants to a temperature drop lasting 2, 4 and 6 hours applied at the beginning, in the middle and at the end of the night were examined. Plant height, leaf petiole length and plant dry weight were measured and, based on the experimental data, the regression dependences of growth variables on the temperature drop were fitted. A method to determine the optimal temperature drop (the duration and time of exposure) which results in shortened plant height and leaf petiole length without a decrease in plant dry weight is proposed.