C3 plant Reaumuria soongorica and C4 plant Salsola passerina are super xerophytes and coexist in a mixed community in either isolated or associated growth, and interspecific facilitation occurs in associated growth. I...C3 plant Reaumuria soongorica and C4 plant Salsola passerina are super xerophytes and coexist in a mixed community in either isolated or associated growth, and interspecific facilitation occurs in associated growth. In the present study, the root traits including root distribution, root length（RL）, root surface area（RSA）, root weight（RW） and specific root length（SRL） of both species in two growth forms were investigated to clarify their response to facilitation in associated growth. Six isolated plants of each species, as well as six associated plants similar in size and development were selected during the plant growing season, and their roots were excavated at 0–10, 10–20, 20–30, 30–40 and 40–50 cm soil depths at the end of the growing season. All the roots of each plant were separated into the two categories of fine roots（2 mm diameter） and coarse roots（≥2 mm diameter）. Root traits such as RL and RSA in the fine and coarse roots were obtained by the root analyzing system WinRHIZO. Most of the coarse roots in R. soongorica and S. passerina were distributed in the top 10 cm of the soil in both growth forms, whereas the fine roots of the two plant species were found mainly in the 10–20 and 20–30 cm soil depths in isolated growth, respectively. However, the fine roots of both species were mostly overlapped in 10–20 cm soil depth in associated growth. The root/canopy ratios of both species reduced, whereas the ratios of their fine roots to coarse roots in RL increased, and both species had an increased SRL in the fine roots in associated growth. In addition, there was the increase in RL of fine roots and content of root N for S. passerina in associated growth. Taken together, the root growth of S. passerina was facilitated for water and nutrient exploration under the interaction of the overlapped roots in both species in associated growth, and higher SRL allowed both species to more effectively adapt to the infertile soil in the desert ecosystem.展开更多
Vegetation and soil surveys were conducted under different site conditions in 2007-2011 to study species diversity using richness, evenness and diversity indices, in the middle portion of the Heihe River Basin. The re...Vegetation and soil surveys were conducted under different site conditions in 2007-2011 to study species diversity using richness, evenness and diversity indices, in the middle portion of the Heihe River Basin. The relationship between species distribution and soil environmental factors was also studied by Canonical Correspondence Analysis （CCA）. Results show that vegetation coverage and species diversity were the highest in the interdune lowland, and the lowest in the mobile dime. Results of the Hill＇s index （di- versity ordering） shows that species diversity is reduced along decreasing soil water content, and the order of species diversity was interdune lowland, flat slope, fixed dune, semifixed dune and mobile dune. The influence degree of soil factors on vegetation dis- tribution was soil water content 〉 pH 〉 total K 〉 organic matter 〉 available N 〉 total N 〉 available K 〉 total P 〉 saline content 〉 available P. Soil water content and pH were important factors significantly affecting spatial distribution difference of vegetation, the environmental explanation was 98%.展开更多
Plants naturally carry microbes on seeds and within seeds that may facilitate development and early survival of seedlings.Some crops have lost seed-vectored microbes in the process of domestication or during seed stor...Plants naturally carry microbes on seeds and within seeds that may facilitate development and early survival of seedlings.Some crops have lost seed-vectored microbes in the process of domestication or during seed storage and seed treatment.Biostimulant microbes from wild plants were used by pre-modern cultures to re-acquire beneficial seed microbes.Today some companies have developed or are developing the use of microbes obtained from soils or plant sources to stimulate plant development and growth.Many of these biostimulant microbes are endophytic in plants.Biostimulant products also include humic substances,which appear to function as signal molecules in plants,triggering increased internalization of soil microbes into root cells and tissues.In addition,protein coatings on seeds fuel the growth of seed surface-vectored microbes,increasing microbial activity around and within roots.In this article,we provide evidence of the endophytic nature of many biostimulant microbes,and suggest that many of the beneficial effects of microbial biostimulants stem from their action as endophytes or as participants or stimulants of rhizophagy cycle activity.展开更多
基金support by the National Natural Science Foundation of China (91025026, 31070359)the National Basic Research Program of China (Y31JA61001)
文摘C3 plant Reaumuria soongorica and C4 plant Salsola passerina are super xerophytes and coexist in a mixed community in either isolated or associated growth, and interspecific facilitation occurs in associated growth. In the present study, the root traits including root distribution, root length（RL）, root surface area（RSA）, root weight（RW） and specific root length（SRL） of both species in two growth forms were investigated to clarify their response to facilitation in associated growth. Six isolated plants of each species, as well as six associated plants similar in size and development were selected during the plant growing season, and their roots were excavated at 0–10, 10–20, 20–30, 30–40 and 40–50 cm soil depths at the end of the growing season. All the roots of each plant were separated into the two categories of fine roots（2 mm diameter） and coarse roots（≥2 mm diameter）. Root traits such as RL and RSA in the fine and coarse roots were obtained by the root analyzing system WinRHIZO. Most of the coarse roots in R. soongorica and S. passerina were distributed in the top 10 cm of the soil in both growth forms, whereas the fine roots of the two plant species were found mainly in the 10–20 and 20–30 cm soil depths in isolated growth, respectively. However, the fine roots of both species were mostly overlapped in 10–20 cm soil depth in associated growth. The root/canopy ratios of both species reduced, whereas the ratios of their fine roots to coarse roots in RL increased, and both species had an increased SRL in the fine roots in associated growth. In addition, there was the increase in RL of fine roots and content of root N for S. passerina in associated growth. Taken together, the root growth of S. passerina was facilitated for water and nutrient exploration under the interaction of the overlapped roots in both species in associated growth, and higher SRL allowed both species to more effectively adapt to the infertile soil in the desert ecosystem.
基金financially supported by the National Natural Sciences Foundation of China (91025026 and 31070359)
文摘Vegetation and soil surveys were conducted under different site conditions in 2007-2011 to study species diversity using richness, evenness and diversity indices, in the middle portion of the Heihe River Basin. The relationship between species distribution and soil environmental factors was also studied by Canonical Correspondence Analysis （CCA）. Results show that vegetation coverage and species diversity were the highest in the interdune lowland, and the lowest in the mobile dime. Results of the Hill＇s index （di- versity ordering） shows that species diversity is reduced along decreasing soil water content, and the order of species diversity was interdune lowland, flat slope, fixed dune, semifixed dune and mobile dune. The influence degree of soil factors on vegetation dis- tribution was soil water content 〉 pH 〉 total K 〉 organic matter 〉 available N 〉 total N 〉 available K 〉 total P 〉 saline content 〉 available P. Soil water content and pH were important factors significantly affecting spatial distribution difference of vegetation, the environmental explanation was 98%.
基金support was provided from USDA-NIFA Multistate Project W4147the New Jersey Agricultural Experiment Station,and from a Cooperative Ecosystems Studies Unit CESU G16AC00433 grant between Rutgers University and the U.S.Geological Survey for control of invasive Phragmites australis,and Rey Juan Carlos University,grant DRIADES-2020/00006/009.
文摘Plants naturally carry microbes on seeds and within seeds that may facilitate development and early survival of seedlings.Some crops have lost seed-vectored microbes in the process of domestication or during seed storage and seed treatment.Biostimulant microbes from wild plants were used by pre-modern cultures to re-acquire beneficial seed microbes.Today some companies have developed or are developing the use of microbes obtained from soils or plant sources to stimulate plant development and growth.Many of these biostimulant microbes are endophytic in plants.Biostimulant products also include humic substances,which appear to function as signal molecules in plants,triggering increased internalization of soil microbes into root cells and tissues.In addition,protein coatings on seeds fuel the growth of seed surface-vectored microbes,increasing microbial activity around and within roots.In this article,we provide evidence of the endophytic nature of many biostimulant microbes,and suggest that many of the beneficial effects of microbial biostimulants stem from their action as endophytes or as participants or stimulants of rhizophagy cycle activity.
