Erianthus species are perennial C4 grasses with such high biomass productivity and high tolerance to environmental stresses that they can be grown in marginal land to supply raw material for cellulosic bioethanol. Bec...Erianthus species are perennial C4 grasses with such high biomass productivity and high tolerance to environmental stresses that they can be grown in marginal land to supply raw material for cellulosic bioethanol. Because high biomass production and strong tolerance to environmental stresses might be based on their large and deep-root system, we closely examined the morphology and anatomy of roots in first-year seedlings of field-grown Erianthus arundinaceus. The deep-root system of E. arundinaceus consists of many nodal roots growing with steep growth angles. Diameter of nodal roots with large variations (0.5 - 5 mm) correlates with the size and number of large xylem vessels. The microscopic observation shows that the nodal roots with dense root hairs developed soil sheath, hypodermis with lignified sclerenchyma in the outer cortex, and aerenchyma in the mid-cortex. In addition, starch grains were densely accumulated in the stele of nodal roots in winter. In the first year, E. arundinaceus developed less lateral roots than other reported grass species. The lateral roots formed a large xylem vessel in the center of the stele and no hypodermis in the outer cortex. Morphology and anatomy of E. arundinaceus root were discussed with reference to strong tolerance to environmental stresses.展开更多
解析植物木质部导水率对逆境的响应和适应对促进植物抗逆性机理研究和受损植被恢复具有重要意义。该文以荒漠河岸林建群种胡杨(Populus euphratica)为研究对象,系统分析了胡杨幼株根、茎、叶水分传输通道对不同浓度盐胁迫的响应和适应...解析植物木质部导水率对逆境的响应和适应对促进植物抗逆性机理研究和受损植被恢复具有重要意义。该文以荒漠河岸林建群种胡杨(Populus euphratica)为研究对象,系统分析了胡杨幼株根、茎、叶水分传输通道对不同浓度盐胁迫的响应和适应。结果表明:(1)胡杨幼株根系对盐胁迫的敏感性高于茎和叶,盐胁迫下根系生长和根尖数显著受到抑制,根木质部易于发生栓塞,导水率明显降低。(2)胡杨幼株茎木质部导水率对盐胁迫的响应依盐浓度而定,轻度(0.05 mol·L–1 Na Cl)和中度(0.15 mol·L–1 Na Cl)盐胁迫下,胡杨可以通过协调导管输水的有效性和安全性来调节木质部的导水率,维持植物正常生长;重度(0.30 mol·L–1 Na Cl)盐胁迫下,胡杨茎木质部导管输水有效性和安全性均明显降低,木质部导水率显著下降,并伴随叶片气孔导度的显著降低,从而严重抑制了胡杨的光合和生长。展开更多
文摘Erianthus species are perennial C4 grasses with such high biomass productivity and high tolerance to environmental stresses that they can be grown in marginal land to supply raw material for cellulosic bioethanol. Because high biomass production and strong tolerance to environmental stresses might be based on their large and deep-root system, we closely examined the morphology and anatomy of roots in first-year seedlings of field-grown Erianthus arundinaceus. The deep-root system of E. arundinaceus consists of many nodal roots growing with steep growth angles. Diameter of nodal roots with large variations (0.5 - 5 mm) correlates with the size and number of large xylem vessels. The microscopic observation shows that the nodal roots with dense root hairs developed soil sheath, hypodermis with lignified sclerenchyma in the outer cortex, and aerenchyma in the mid-cortex. In addition, starch grains were densely accumulated in the stele of nodal roots in winter. In the first year, E. arundinaceus developed less lateral roots than other reported grass species. The lateral roots formed a large xylem vessel in the center of the stele and no hypodermis in the outer cortex. Morphology and anatomy of E. arundinaceus root were discussed with reference to strong tolerance to environmental stresses.
文摘解析植物木质部导水率对逆境的响应和适应对促进植物抗逆性机理研究和受损植被恢复具有重要意义。该文以荒漠河岸林建群种胡杨(Populus euphratica)为研究对象,系统分析了胡杨幼株根、茎、叶水分传输通道对不同浓度盐胁迫的响应和适应。结果表明:(1)胡杨幼株根系对盐胁迫的敏感性高于茎和叶,盐胁迫下根系生长和根尖数显著受到抑制,根木质部易于发生栓塞,导水率明显降低。(2)胡杨幼株茎木质部导水率对盐胁迫的响应依盐浓度而定,轻度(0.05 mol·L–1 Na Cl)和中度(0.15 mol·L–1 Na Cl)盐胁迫下,胡杨可以通过协调导管输水的有效性和安全性来调节木质部的导水率,维持植物正常生长;重度(0.30 mol·L–1 Na Cl)盐胁迫下,胡杨茎木质部导管输水有效性和安全性均明显降低,木质部导水率显著下降,并伴随叶片气孔导度的显著降低,从而严重抑制了胡杨的光合和生长。
