水分条件对烤烟主要化学成分的影响研究   总被引：8，自引：0，他引：8       下载免费PDF全文

颜合洪 《中国生态农业学报》2005,13(1):101-103

不同水分条件对盆栽烤烟“G80”品种主要化学成分的影响研究结果表明 ,经不同淹水处理后烟株中、上部烟叶总糖、K和烟碱含量减少 ,总N和蛋白质含量增加 ,且均达极显著水平 ,这 2种变化趋势均随处理水平的升高而增大 ;不同生育期干旱处理烟株、上部烟叶总糖、烟碱和总N含量极显著上升 ,K和蛋白质含量极显著下降 ,但伸根期和成熟期干旱处理间烟株中部烟叶主要化学成分无显著差异。  相似文献   

Nodulation and growth of mycorrhizal Casuarina equisetifolia J.R. and G. First in response to flooding   总被引：1，自引：0，他引：1  

M. A. Osundina 《Biology and Fertility of Soils》1997,26(2):95-99

The influence of vesicular-arbuscular mycorrhizal (VAM) inoculation on nodulation and growth of flooded Casuarina equisetifolia J.R. and G. First was investigated. Casuarina seedlings were grown in sterile soil inoculated with Glomus clarum Nicolson and Schenick and flooding was imposed for 8 weeks. Mycorrhizal Casuarina seedlings adapted to flooding better than non-inoculated seedlings. This was achieved partly by the greater development of adventitious roots and hypertrophied lenticels which increased oxygen availability, and therefore VAM infection in the upper soil zone. The VAM infection led to the suppression of the accumulation of toxic products of anaerobic respiration, such as ethanol. Mycorrhizal inoculation also prevented the total suppression of nodulation in the flooded plants. Nodulation was observed only in the upper soil zone, and its occurrence made dinitrogen fixation possible. The results suggest that mycorrhizal infection is essential for nodulation of Casuarina in flooded soils and is therefore related to the relatively higher dinitrogen accumulation in Casuarina under anoxic conditions. Received: 12 December 1996  相似文献   

Conserving the terecay (Podocnemis unifilis, Testudines: Pelomedusidae) through a community-based sustainable harvest of its eggs     

Francesco Paolo Caputo  Daniele Canestrelli  Luigi Boitani 《Biological conservation》2005,126(1):84-92

The exploitation of South American river turtles as a food source has long been considered the main factor contributing to the decline of populations. Along a stretch of the Aguarico River (Ecuador), we investigated the spatial and temporal distribution of terecay (Podocnemis unifilis) nests, factors affecting nest outcome, and the effect of offering a reward for each hatchling captured on the pattern of egg consumption by the local human community. Flooding influence on egg mortality appears to be particularly important in this Amazonian region, destroying 63.1% of all nests. This amount of nests resulted more than sufficient to satisfy the local community’s consumption needs (28.2%). The proposed reward for each hatchling ensured the voluntary participation of the Cofan people in the terecay conservation project, leading to: (i) nests being harvested only from sites where there were likely no hatching possibilities, (ii) efficient management and protection of nesting beaches with abolition of poaching of nests and adult females, and (iii) transplantation of nests from sites that would be flooded (and whose yield exceeds human consumption). Therefore, we argue that in this area of Aguarico River there are both biologically and socially favourable conditions for the establishment of a sustainable harvest of terecay eggs. Possible factors determining high nest mortality due to flooding in this area, as well as opportunities to make the project evolve toward economic self-sustainability, will also be discussed.  相似文献   

Conditioning factors in flooding of karstic poljes—the case of the Zafarraya polje (South Spain)     

M. Lpez-Chicano  M. L. Calvache  W. Martín-Rosales  J. Gisbert 《CATENA》2002,49(4)

The Zafarraya polje undergoes periodical flooding, of which the last episode (1996–1997) was analysed in detail on this paper. On the basis of the retention curves of the two lakes that formed in the northwestern and southwestern sectors, we calculated the total infiltration capacity of the polje to have a maximum value of 3–3.5 m³/s and so we infer that when the flow of the Arroyo de la Madre exceeds this figure, there will be a risk of flooding in the polje. We also propose a model for the 1996 flood that can be extended to other similar occurrences in this and other poljes where we can establish the role played by groundwater and surface water during this flood. In response to the heavy precipitation, the flow of the Arroyo de la Madre rose abruptly, exceeding the infiltration capacity of the main swallow holes on the polje, causing first the northern lake and then the southern lake to form with only surface water supply. The water table of the karst aquifer rose sharply, reaching a situation of equilibrium between the level in the lakes and the water table in this sector of the karst aquifer that prevented infiltration through the swallow holes. In the case of the southern lake, there were even cases of swallow holes that began to operate as estavelles. During this phase of maximum flooding, one single lake was present, which was divided into two once more when the water table of the karst aquifer in the polje sector began to fall and surface supply also began to decrease.  相似文献   

水淹对野古草和秋华柳不定根形成的影响     

陈婷  曾波  叶小齐  罗芳丽  刘巅 《安徽农业科学》2007,35(19):5703-5704,5712

在不同水淹缺氧环境条件下,对三峡库区岸生植物野古草和秋华柳不定根的形成情况进行研究。结果表明:(1)在连续水淹条件下,野古草不定根的生成早于秋华柳植株;(2)随着连续底淹时间的增加,秋华柳不定根生长有增加的现象,但增长量不显著;(3)连续底淹30 d前,野古草植株不定根的生长量随水淹时间的增加而不断增长;30 d后,不定根量开始减少;(4)不同的水淹方式下,野古草植株不定根的生长情况不同,水淹10 d时,底淹和全淹的野古草不定根生长量无明显差异;水淹20 d后,底淹的野古草不定根生长量都明显高于全淹环境中的野古草;(5)全淹环境中的秋华柳植株几乎无不定根的生成,只在全淹60 d后一两株秋华柳植株有不定根生长现象。可见不同的水淹时间和水淹方式对秋华柳和野古草不定根的形成有着不同程度的影响。  相似文献   

Survival of submerged larvae of cranberry girdler, Chrysoteuchia topiaria, in the laboratory     

Sheila M. Fitzpatrick   《Crop Protection》2007,26(12):1810-1816

Flooding for several days in late summer or early fall is reported to control larvae of the cranberry girdler, Chrysoteuchia topiaria (Zeller) (Lepidoptera: Pyralidae), which feed on roots of cranberry, Vaccinium macrocarpon Aiton (Ericales: Ericaceae). During flooding, larvae float to the surface or remain submerged. Floating larvae are vulnerable to bird predation, but the fate of submerged larvae has not been studied. The factorially designed laboratory experiments reported here examined survival of submerged cranberry girdler larvae at water temperatures of 10, 15 or 20 °C, and flood durations of 24, 48 or 72 h. These conditions are characteristic of floods applied to western Canadian cranberry farms. In the first year of the study, more submerged larvae survived at 10 °C than at 15 or 20 °C, and more survived 24-h submersion than 48- or 72-h submersion; there was no difference between survival at 15 and 20 °C or 48- and 72-h submersion. In the second year of the study, when there were no 10 °C treatments, more submerged larvae survived at 15 than at 20 °C, and more survived 24-h submersion than 72-h submersion; survival after 48 h was not significantly different from survival after 24 or 72 h. In both years, there was no interaction effect of water temperature and duration of submersion: survival of submerged larvae decreased with longer flood durations and higher temperatures. Dissolved oxygen concentrations before submersion ranged from 5.8±0.1 to 6.3±0.2 ppm in the first year, and 5.5±0.1 to 5.7±0.1 ppm in the second. After submersion, dissolved oxygen concentrations in cups with larvae were approximately 0.5 ppm lower than in cups without larvae, suggesting that larvae continued to respire and use oxygen for some time after submersion. Results of the experiments are used to improve guidelines for flooding to control cranberry girdler larvae.  相似文献   

茄子品种资源苗期耐涝性鉴定研究   总被引：1，自引：0，他引：1  

张路  曾令辉  朱丽丽  朱俊桥  杨旭 《安徽农业科学》2015,(22):125-127

[目的]筛选耐涝性较强的茄子种质资源.[方法]对20份茄种质资源进行水分胁迫后,通过测定叶绿素损失率、幼苗死亡率及统计恢复指数综合评价其耐涝性.[结果]根据幼苗死亡率、恢复指数结合表型症状综合分析,试验材料的耐涝性可分为3个级别:耐涝性强的品种有苏州牛角、荷包茄、济南六叶茄、墨茄王、许昌紫茄、盐城青长茄、火金刚长茄;中等耐涝品种有铜仁野紫茄、白龙王子、汉红2号、圆茄子、日本茄-1、10-26;不耐涝品种有石东早红茄、绿宝石、墨玉长茄、贵阳紫团茄、早白茄、树型茄.[结论]试验结果为生产中选择耐涝茄子品种及加速茄子耐涝品种的选育提供了依据.  相似文献   

淹水胁迫对嫁接甜椒幼苗几种抗氧化酶活性和渗透调节物质的影响   总被引：1，自引：0，他引：1  

朱丽华  龚繁荣 《江西农业学报》2013,(10)

研究了淹水胁迫对嫁接甜椒幼苗抗氧化酶活性和渗透调节物质含量的影响,结果表明:随着淹水胁迫时间延长,嫁接甜椒苗丙二醛(MDA)含量和O2-·生成速率增加,嫁接苗含量显著低于自根苗;超氧物歧化酶(SOD)、过氧化物酶(POD)、脯氨酸和可溶性糖含量均表现上升的趋势,以上指标嫁接苗均高于自根苗。由此可知,淹水胁迫下嫁接苗有较高的抗氧化酶活性和较低的氧化损伤,从而增强甜椒的耐淹水性。  相似文献   

不同灌溉方式对设施菠菜生长及产量的影响     

董畔  刘云  宋炳彦  杨阳  梁玉芹 《蔬菜》2017,(8):47-49

针对设施菠菜灌溉方式不合理导致的菠菜产量降低、长势欠佳等问题,研究漫灌和微喷对其产量、长势及叶绿素含量的影响。结果表明:菠菜株高在微喷灌溉方式下较漫灌提高了10%,叶茎比提高了17.67%;微喷灌溉方式较漫灌有效提高了菠菜产量和叶绿素含量,产量提高近10%,叶绿素含量提高5.5%,节水30.56%,且促进农民增收20.60%。综合考虑,微喷更适合于设施菠菜的生长。  相似文献   

Ecological studies on Echinochloa crus-galli and the implications for weed management in direct-seeded rice     

B.S. Chauhan  D.E. Johnson 《Crop Protection》2011,30(11):1385-1391

Echinochloa crus-galli, a C₄ grass, is one of the world’s most serious weeds. Weed management decisions for this species can be derived from knowledge of its seed biology. Studies were conducted to determine the effects of light on germination; seed burial depth and rice residue on emergence and growth; and flooding time and depth on emergence, survival and growth of this species. Light stimulated seed germination but it was not an absolute requirement for germination. The proportion of seeds germinating was greatest for seeds placed on the soil surface (92%), and emergence declined with increasing burial depth in soil; no seedlings emerged from the depth of 8 cm. A burial depth of only 0.4 cm reduced seedling emergence by 50%. Seedling emergence and seedling biomass were reduced by the addition of high level (6 ton ha⁻¹) of rice residue to the soil surface. Early and deep flooding significantly suppressed growth of E. crus-galli seedlings. In flooded conditions, with increased water depth the weed allocated more biomass to shoots at the expense of roots. The information gained from this study could contribute to improve weed control approaches. Soil inversion by tillage to bury weed seeds below their maximum depth of emergence, use of crop residue as mulch and early flooding of the crop could serve as important tools for managing E. crus-galli and other weed species with similar germination requirements. These management options, however, would need to be compatible with other crop management requirements.  相似文献