共查询到20条相似文献,搜索用时 46 毫秒
1.
PENG Yu ZHANG Haiyang GUO Kaikai DING Yibo WANG Xudong 《Journal of Landscape Research》2019,(2):41-43
The road lighting system and the road greening system, which are mutually interrelated and independent, are two important parts in the urban road environment. Unreasonable road lighting is easy to induce light pollution and has a great negative impact on the physiology and growth of garden plants in the urban green space. In this paper, 21 kinds of common tree species in the urban green space of Zhengzhou were selected as the research object, and the photosynthetic physiological parameters of landscape trees under the LED light source were observed using LI-6400 Photosynthesis System. This paper attempted to find the critical point for initiating photosynthesis of different types of tree species under a certain light source and then calculated the safe distance between lighting fixtures and landscape trees. The results showed that road lighting interfered with the photosynthetic physiological activities of the surveyed trees, affecting the normal dormancy of the plants at night; the sensitivity of different tree species to night lighting was different, and there were some differences in the light compensation points, so the corresponding safe distance was also different. It is hoped that this study can provide a valuable reference and scientific basis for urban road greening and lighting design. 相似文献
2.
王景会 《农产品加工.学刊》2005,(11):26-27
利用植物生物反应器生产口服疫苗已成为目前研究的热点。与传统疫苗相比,植物源性疫苗具有安全、稳定、高效和廉价等优点。植物作为生产疫苗的载体可将抗原表达于植物的可食部位。当植物被食用或饲喂时,植物源性疫苗可激发保护性的黏膜免疫应答。综述了植物源性口服疫苗的原理,并对可能出现的问题及解决途径进行了探讨。 相似文献
3.
4.
The effect of various periods of exposure to suboptimal temperature ('warm breaks'– WB: 14 °C for 4 h, 1 h and 0 h – control in 24 h cycles) during chilling (5 °C) of maize seedlings on the photosynthesis, the photochemical efficiency of photosystem II (Fv/Fm) and on the injuries of the cell membranes of leaves and water content in plants was compared. The measurements were conducted after 1, 3, 7 and 12 chill cycles. It was found that WB of either length distinctly diminished the chill-induced inhibition of net photosynthesis and the decrease of photochemical efficiency of PSII. The protective effect on WB on these parameters was observed shortly after completion of chilling of the plant as well as an after-effect. Daily warming up of the plants also reduced the leakage of electrolytes and diminished the water deficit of the chilled seedlings. The protective effect of WB on the measured parameters of the plants was greater in the chill-sensitive genotype than in the chill-tolerant one, especially when plants were warmed up for 4 h. The results obtained are an indication that short periods of warm weather during cold spring may diminish the injuries of the photosynthetic apparatus, as well as reduce the disturbance of water status of seedlings, contributing in this way to better condition of maize crops. 相似文献
5.
6.
为指导化学除草剂砜嘧磺隆在烤烟生产上的应用,在旺长初期,采取烟株茎叶定向喷雾的方法,研究砜嘧磺隆施用后烤烟的药害,评价其安全性,筛选奈安、芸苔素内脂2种保护剂与砜嘧磺隆混施,开展保护性试验。试验结果表明,25%碸嘧磺隆会对烤烟快速产生最高7级程度的药害,但药害症状表现期较短,施药10天后基本消失,15天后全部消失,烟株恢复正常生长,成熟期的烟叶无药剂残留。2种保护剂可对砜嘧磺隆产生的药害起到一定缓解修复作用;奈安保护剂使用效果优于芸苔素内酯,但两者对直接接触到药液的叶片影响效果修复不显著;2种保护剂降低了砜嘧磺隆对杂草的防效和持效期。在烟叶生产活动中砜嘧磺隆施用的有效浓度以50~58.3 mg/kg为宜,一旦发现烟株有明显的药害症状表现,即可喷施奈安或芸苔素内酯进行保护性修复。 相似文献
7.
G. Geisler S. A. Shrief A. F. Ibrahim R. Shabana 《Journal of Agronomy and Crop Science》1992,168(1):20-33
Investigations on the effect of competition on stand structure of spring oilseed rape
On the basis of a field experiment with spring oilseed rape, frequency distributions of plant dry matter and plant height were investigated. Samples were taken at four developmental stages: rosette, begin of flowering, end of flowering, ripeness (harvest). To understand the effect of competition in a plant population on frequency distribution, distance of rows (16 cm, 32 cm) and number of plants (60, 90 and 120 plants/m2 ) were varied. Differences in frequency distribution were estimated by skewness and kurtosis.
The results show that with age of the plant population the skewness of the plant character dry matter decreases from a high positive value till ripeness to a low positive value; kurtosis also decreases during development and tends to a value of 0 at ripeness. The effect of competition as produced by number of plants for area is mirrored by a positive skewness increasing with increasing number of plants per area. The value for kurtosis also increases with the stronger competition as consequence of plant density. Row distance did not show specific effects of frequency distribution. Plant height did, generally speaking, not react to competition. 相似文献
On the basis of a field experiment with spring oilseed rape, frequency distributions of plant dry matter and plant height were investigated. Samples were taken at four developmental stages: rosette, begin of flowering, end of flowering, ripeness (harvest). To understand the effect of competition in a plant population on frequency distribution, distance of rows (16 cm, 32 cm) and number of plants (60, 90 and 120 plants/m
The results show that with age of the plant population the skewness of the plant character dry matter decreases from a high positive value till ripeness to a low positive value; kurtosis also decreases during development and tends to a value of 0 at ripeness. The effect of competition as produced by number of plants for area is mirrored by a positive skewness increasing with increasing number of plants per area. The value for kurtosis also increases with the stronger competition as consequence of plant density. Row distance did not show specific effects of frequency distribution. Plant height did, generally speaking, not react to competition. 相似文献
8.
The effect of interplant distance on differentiation and selection a) of the superior lines from a mixture of inbred lines,
and b) of individual plants originating from the top lines, was studied in chickpeas (Cicer arietinum L.). For this, 28 chickpea inbred lines were evaluated on a single plant basis in a honeycomb design and in the same field
at three interplant distances, for four growing seasons, at Larissa, Greece. The interplant distances were 15 cm (520000plants/ha,
strong allo-competition), 30 cm(128630 plants/ha, medium allo-competition) and 100 cm (11500plants/ha, without competition).
In addition, the inbred lines were evaluated in replicated plot trials under an agronomically accepted plant stand (520000plants/ha,
crop environment) and the ranking of the 28 lines based on the average yield per plot over growing seasons was determined.
Selection was applied in each season for each interplant distance and the three and six top lines with the highest average
yield per plant were identified. These top lines from each interplant distance were compared with the three and six top lines(say:
proven superior lines) identified after their evaluation under crop environment over seasons. In addition, selection was applied
at the individual plant level with six selection pressures in each season and each interplant distance. Then we determined
for each experiment and selection pressure the number of the selected plants which belonged to the six proven top lines. It
was observed that the ranking obtained under crop environment was best correlated with the ranking at the intermediate interplant
distance (30 cm), followed by the ranking at the high interplant distance (100 cm). In contrast this correlation was very
weak for the ranking at low interplant distance (15 cm).In addition, the interplant distance identifying the highest number
of the proven high yielding lines after their evaluation in one season was the intermediate interplant distance followed by
the high interplant distance and certainly not the low interplant distance. The relative effectiveness was further increased
when selection was based on average performance of the lines across seasons. This, together with the relatively small number
of seeds produced per plant, renders selection at low interplant distance less favorable than selection at the intermediate
or high interplant distance.The individual plant selection was effective at all three interplant distances. Selection effectiveness
generally increased as the selection pressure increased. Again the best results were obtained when selection was applied at
intermediate or at high interplant distance. It was concluded that line selection as well as individual plant selection was
more effective at intermediate interplant distance and certainly not at low interplant distance.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
9.
Prerna Balkrishna Pawar Jose Savio Melo Hemlata Madhav Kotkar Mohan Vinayak Kulkarni 《Journal of Crop Science and Biotechnology》2018,21(1):23-33
Arbuscular Mycorrhizal fungi (AMF) play an important and increasingly well-recognized role in agro ecosystems. Beneficial soil microorganisms like arbuscular mycorrhizal fungi and soil health are key factors for producing safe plants. Arbuscular mycorrhizal fungi form a symbiotic association with roots of plants and facilitate plant growth through enhancing uptake of several macro- and micro-nutrients of low mobility in soil, like phosphorus, zinc, copper, etc. In the present study, we investigated the effect of 10 different isolated mycorrhizal species viz. Glomus mosseae, Glomus clarum, Glomus fasciculatum, Glomus intraradices, Glomus ambisporum, Gigaspora gigantea, Acaulospora denticulata, Glomus globiferum, Gigaspora albida, and Glomus pansiholus on growth, yield, and essential nutrient content of groundnut (Arachis hypogeae L.). Plants inoculated with arbuscular mycorrhizal fungi showed significant increments in growth, yield, and nutrient uptake as compared to control (uninoculated) plants. Amongst all, plants inoculated with Glomus mosseae were more efficient in increasing growth parameters, enzymatic activities of nitrate reductase, and alkaline phosphatase as well as total yield as compared to other mycorrhizal inoculated plants. Overall, the study showed an additive effect of all mycorrhizal species on plant physiology. Thus, this study provides an important insight that arbuscular mycorrhizal fungi are most suitable for sustainable agriculture which will improve and help in increasing the growth as well as yield of groundnut. 相似文献
10.
11.
为摸清毛乌素沙区食用资源植物类型、用途,确定该区食用资源植物名录,以期为合理利用、有效保护该区资源植物提供科学依据,通过毛乌素沙综合考察,考察采用东、中、西三条线路,经过三个阶段,历时21d,行程5 000km,获得丰富的资料,并结合文献资料进行分析、研究、论证。结果表明毛乌素沙区食用资源植物共有8类82科229属320种,毛乌素沙区食用植物资源较丰富。 相似文献
12.
聚丙烯酰胺(PAM)作为一种性能优良的高分子聚合物,近年来广泛应用于农业水土保持及土壤改良。通过文献调研,在综述PAM对土壤中重金属作用及机理基础上,分析了其对土壤重金属污染植物修复的应用潜力:(1)PAM及其改性产物施用于土壤后可吸附特定的重金属离子,降低重金属对植物的毒害作用,但效果受pH值、温度等条件影响;(2)PAM在改善土壤理化性质的同时,可通过吸附、螯合及络合等作用抑制重金属的生物有效性,从而改善修复植物的生长条件。尽管PAM降解产物之一的丙烯酰胺单体(AMD)具有神经毒性,但是通过调节施加方式及引入降解微生物等方法可以避免PAM降解对土壤产生不良影响,进而将健康风险控制在安全范围内。因此,PAM是环境友好的重金属污染土壤植物修复促进剂,且其环境风险可控。 相似文献
13.
高温胁迫对景天植物膜脂过氧化及保护酶活性的影响 总被引:6,自引:2,他引:4
研究高温胁迫对景天植物的膜脂过氧化程度及保护酶活性的影响。以5种景天植物为试材,进行45℃/30℃(白13 h/昼11 h)高温胁迫,高温胁迫前及胁迫后每5天取叶片测定相关生理指标,分析膜脂过氧化程度及保护酶活性的变化。随着高温胁迫程度加重,5种景天植物的O2.-产生速率和MDA含量持续上升,耐热性强的景天植物O2.-产生速率上升慢、MDA含量积累少;胁迫过程中,5种景天植物的SOD、POD、CAT活性均高于胁迫前,说明高温胁迫诱导3种酶活性增强,3种酶活性在整个胁迫过程中呈现先升后降的趋势,耐热性强的景天植物SOD、POD、CAT活性增幅高。高温胁迫下通过增强SOD、POD、CAT活性以减轻膜脂过氧化程度是景天植物适应高温胁迫的重要生理机制。 相似文献
14.
WANG Ling-dong 《保鲜与加工》2004,(12):68-72
When the building is on fire,there is a certain requirement to evacutate people safely.In fact the requirement is normally executed by certain standard. Nowadays, both internal and external experts have proposed many ways to change current dealing models to functional standard models.But there need to be further research for functional design of distance on safe evacutation.Based on the dissection of current existed inadequacy,this thesis covers a higher standard of safe distance.That is,if the fire brokes out inside of the building,people should estimate the safe distance according to smoke and heat of the fire,the influnence of the circumstances to time and speed on evacutation.The paper connects engineering theroy of safty of fire disaster and then it designs a model to evacutate people safely.The model will play a part in promoting designing a more functional antifire structure. 相似文献
15.
噻虫啉拌种对玉米幼苗生理生化指标的影响 总被引:2,自引:2,他引:0
[目的]为明确噻虫啉悬浮种衣剂拌种对玉米幼苗生长的影响,以及对玉米幼苗叶片保护酶和根系活力的影响。[方法]通过室内盆栽法,以噻虫啉浓度为2 g/kg、4 g/kg、5 g/kg、6 g/kg、8 g/kg(种子)拌种,测定玉米幼苗三叶一心期的生物学性状、根系活力和叶片保护酶。[结果]结果表明:噻虫啉拌种能显著提高玉米幼苗的各生长指标、叶片保护酶活性和根系活力,随着噻虫啉浓度的增加呈现出先升高后降低的趋势,且浓度为4-5 g/kg(种子)拌种处理大于吡虫啉处理, 8g/kg(种子)处理对玉米植株的生长有轻微的抑制作用,但叶片保护酶和根系活力仍高于对照。[结论]研究表明:适宜剂量的噻虫啉拌种处理可以显著促进玉米幼苗的生长。 相似文献
16.
Effective maize pollen dispersal in the field 总被引:3,自引:0,他引:3
Summary The study was set up to gain information on the effective dispersal of maize pollen and the degree of randomness in mating.The results show that plants near the source tend to receive a greater quantity of pollen than those further away. It was further observed that the effective pollen dispersal was not uniform in all directions. In addition, the distance measured in number of plants is more important in assessing the efficiency of pollen dispersal than the distance in meters.The findings indicate that maize is indeed a panmitic population, in which a great number of parents or the male gametes are considerably mixed. 相似文献
17.
Chen Hongyi 《保鲜与加工》1998,(5):93-98
This paper the expounds intension of the safety systems engineering, makingbetter systematic analyses on the cause of formation of accidents. And an idea using theprinciples and method of the safety system engineering to strengthen safe administrationin building is proposed. 相似文献
18.
石灰炉渣废弃地中Pb、Cu、Zn、Cd重金属有效态含量均高于临近对照土壤,其炉渣淋出液对绿豆、蚕豆、玉米3种植物种子发芽率无影响,但均抑制其发芽势和下胚轴伸长,根长抑制率达30%~50%以上,对敏感种子黄豆的发芽率、发芽势(4d)影响明显,摸拟盆栽一个月苗期,4种植物试验组在总叶面积、株高、生物量方面均低于对照组;生理生化测定,4种植物其体内抗逆性保护物质脯氨酸(PRO)和膜过氧化产物丙二醛(MDA)含量试验组均高于对照组。试验表明:重金属是石灰炉渣废弃地植物定居、生长、繁殖的主要协迫因子之一。 相似文献
19.
石灰炉渣废弃地重金属对植物生长的影响 总被引:2,自引:0,他引:2
石灰炉渣废弃地中Pb、Cu、Zn、Cd重金属有效态含量均高于临近对照土壤,其炉渣淋出液对绿豆、蚕豆、玉米3种植物种子发芽率无影响,但均抑制其发芽势和下胚轴伸长,根长抑制率达30%~50%以上,对敏感种子黄豆的发芽率、发芽势(4d)影响明显,摸拟盆栽一个月苗期,4种植物试验组在总叶面积、株高、生物量方面均低于对照组;生理生化测定,4种植物其体内抗逆性保护物质脯氨酸(PRO)和膜过氧化产物丙二醛(MDA)含量试验组均高于对照组。试验表明:重金属是石灰炉渣废弃地植物定居、生长、繁殖的主要协迫因子之一。 相似文献