...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Plant and Soil >Oxygen distribution and movement, respiration and nutrient loading in banana roots (Musa spp. L.) subjected to aerated and oxygen-depleted environments
【24h】

Oxygen distribution and movement, respiration and nutrient loading in banana roots (Musa spp. L.) subjected to aerated and oxygen-depleted environments

机译：曝气和缺氧环境下香蕉根（Musa spp。L.）的氧气分布和运动，呼吸和养分含量

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Excessive soil wetness is a common feature where bananas (Musa spp.) evolved. Under O-2 deficiency, a property of wet soils, root growth and functions will be influenced by the respiratory demand for O-2 in root tissues, the transport of O-2 from the shoot to root and the supply of O-2 from the medium. In laboratory experiments with nodal roots of banana, we examined how these features influenced the longitudinal and radial distributions of O-2 within roots, radial O-2 loss, solute accumulation in the xylem, root hydraulic conductivity, root elongation and root tip survival. In aerated roots, the stele respired about 6 times faster than the cortex on a volume basis. Respiratory O-2 consumption decreased substantially with distance from the root apex and at 300-500 mm it was 80% lower than at the apex. Respiration of lateral roots constituted a sink for O-2 supplied via aerenchyma, and reduced O-2 flow towards the tip of the supporting root. Stelar anoxia could be induced either by lowering the O-2 partial pressure in the bathing medium from 21 to 4 kPa (excised roots) or, in the case of intact roots, by reducing the O-2 concentration around the shoot. The root hair zone sometimes extended to 1.0 mm from the root surface and contributed up to a 60% drop in O-2 concentration from a free-flowing aerated solution to the root surface. There was a steep decline in O-2 concentration across the epidermal-hypodermal cylinder and some evidence of a decline in the O-2 permeability of the epidermal-hypodermal cylinder with increasing distance from the root apex. The differences in O-2 concentration between cortex and stele were smaller than reported for maize and possibly indicated a substantial transfer rate of dissolved O-2 from cortex to stele in banana, mediated by a convective water flow component. An O-2 partial pressure of 4 kPa in the medium reduced net nutrient transfer into the vascular tissue in the stele within 1 or 2 h. Hypoxia also caused a temporary decrease in radial root hydraulic conductivity by an order of magnitude. In O-2 deficient environments, the stele would be among the first tissues to suffer anoxia and O-2 consumption within the root hair zone might be a major contributor to root anoxia/hypoxia in banana growing in temporarily flooded soils.
机译：过度潮湿是香蕉（Musa spp。）进化的共同特征。在O-2缺乏的情况下，湿润土壤的性状，根的生长和功能将受到根组织中O-2的呼吸需求，O-2从枝条到根的运输以及O-2的供应的影响。媒介。在香蕉节根的实验室实验中，我们研究了这些特征如何影响根中O-2的纵向和径向分布，径向O-2损失，木质部中的溶质积累，根部水力传导率，根部伸长率和根尖存活率。在充气的根中，石碑的呼吸量比皮层快约6倍。呼吸O-2消耗量随着距根尖的距离而显着降低，在300-500 mm处比在根尖低80％。侧根的呼吸构成了通过气孔供应的O-2的汇，并减少了向支撑根尖端的O-2流量。可以通过将沐浴介质中O-2的分压从21 kPa降低到4 kPa（已切除的根）来诱导Steaf缺氧，或者对于完整的根，可以通过降低枝条周围的O-2浓度来诱导缺氧。根部毛发区域有时会延伸到距根表面1.0毫米处，并导致从自由流动的充气溶液到根表面的O-2浓度下降60％。穿过表皮-次表皮圆柱体的O-2浓度急剧下降，并且一些证据表明表皮-次表皮圆柱体的O-2渗透性随着与根尖距离的增加而降低。皮层和石碑之间的O-2浓度差异小于玉米报道的水平，并且可能表明溶解的O-2从对流水流介导的香蕉中的皮层到石碑的大量转移速率。培养基中4 kPa的O-2分压会在1或2小时内减少净营养素转移到碑石的血管组织中。低氧还导致径向根部水力传导率暂时降低了一个数量级。在O-2缺乏的环境中，石碑将是最早遭受缺氧的组织之一，而在根毛区内消耗O-2可能是造成临时淹水土壤中香蕉生长根缺氧/缺氧的主要原因。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号