Objective] In order to improve the survival rate of Hippophae rhamnoides hardwood cuttings, cultivate high-quality sea buckthorn seedlings. [Method] This pa-per took hard branches of Russian big fruit H. rhamnoides as...Objective] In order to improve the survival rate of Hippophae rhamnoides hardwood cuttings, cultivate high-quality sea buckthorn seedlings. [Method] This pa-per took hard branches of Russian big fruit H. rhamnoides as material. The days of striking roots, rate of striking roots,root length and number of adventitious root were determined. [Result] The cuttings col ected from upper treetops were obviously inferi-or to the lower ones. Three years cutting is obviously better than one or two years. Cuttings from lower branches were not so good as the cuttings from upper branch-es. Base oblique incisions were clearly superior to paper-cover incision. The optimal length of cuttings was 20-25 cm. The rooting rate of cuttings was the highest by fast dipping with NAA of 50 mg/L. [Conclusion] The study provides theoretical basis for H. rhamnoides artificial cultivation.展开更多
Roots play an important role in stabilizing and strengthening soil. This article aims to study the mechanical properties of the interface between soil and roots with branches, using the pullout test method in the labo...Roots play an important role in stabilizing and strengthening soil. This article aims to study the mechanical properties of the interface between soil and roots with branches, using the pullout test method in the laboratory. The mechanical properties of the soil-root with branches interface is determined through the pullout-force and root-slippage curve （F-S curve）. The results of investigating 24 Pinus tabulaeformis single roots and 55 P. tabulaeformis roots with branches demonstrated three kinds of pullout test failures： breakage failure on branching root, breakage failure on branching node, and pullout failure. The branch angle had a remarkable effect on the failure mode of the roots with branches： the maximum pullout force increased with the sum of the branch diameters and the branch angle. The peak slippage and the initial force had a positive correlation with the sum of the branch diameter. The sig- nificance test of correlation between branch angle and the initial force, however, showed they had no correlation. Branch angle and branch root diameter affect the anchorage properties between root system and soil. Therefore, it is important to investigate the anchorage mechanics of the roots with branches to understand the mechanism of root reinforcement and anchorage.展开更多
Dalbergia sissoo Roxb. is one of the promising multipurpose tree species of South Asia. Most of the plantations of D. sissoo from seeds are facing severe threats due to the die-back disease, which ultimately causes de...Dalbergia sissoo Roxb. is one of the promising multipurpose tree species of South Asia. Most of the plantations of D. sissoo from seeds are facing severe threats due to the die-back disease, which ultimately causes death of this potential tree-species within a few months. Vegetative propagation could avoid the die-back disease. Thirty mother trees of different age-groups of D. sissoo were selected for evaluating the rooting behaviour of branch cuttings from D. sissoo as influenced by auxins （IAA or IBA at 100, 200, 500 mg·L^-1）, ages of mother trees （10, 4 and 2 years old） and different environment conditions, i.e., different mediums （soil and sand） or light conditions （in shade and open condition）. The results show that application of IAA and IBA induced more numbers of cuttings （collected from 10-year-old mother trees） to root compared to control. Branch cuttings of D. sissoo collected from 10-year-old mother trees and planted in soil bed in open conditions had 100.0% of cuttings to root in IAA （100 mg·L^-1） and IBA （200 mg·L^-1） treatments. Both rooting medium （Soil and sand） influenced significantly （p〈0.05） on rooting response of branch cuttings. Soil medium was found to achieve maximum no. of branch cuttings to root, compared to sand medium.展开更多
Background:The terminal branch orders of plant root systems are increasingly known as an ephemeral module.This concept is crucial to recognize belowground processes.However,it is unknown if root modules still exist af...Background:The terminal branch orders of plant root systems are increasingly known as an ephemeral module.This concept is crucial to recognize belowground processes.However,it is unknown if root modules still exist after they die?Methods:The decomposition patterns of the first five root orders were observed for 3 years using a branch-order classification,a litter-bag method and sequential sampling in a common subalpine tree species(Picea asperata)of southwestern China.Results:Two root modules were observed during the 3-year incubation.Among the first five branch orders,the first three order roots exhibited temporal patterns of mass loss,nutrients and stoichiometry distinct from their woody mother roots throughout the experimental period.This study,for the first time,reported the decomposition pattern of each individual root order and found a similar decomposition dynamic among ephemeral root branches in a forest tree species.Conclusions:Results from this study suggest that root modules may also exist after death,while more data are needed for confirmation.The findings may further advance our understanding of architecture-associated functional heterogeneity in the fine-root system and also improve our ability to predict belowground processes.展开更多
Bambusa vulgaris Schrad ex wendl is a widely cultivated bamboo species in rural Bangladesh for its versatile uses. The vegetative propagation becomes the only viable alternative for this species because B. vulgaris do...Bambusa vulgaris Schrad ex wendl is a widely cultivated bamboo species in rural Bangladesh for its versatile uses. The vegetative propagation becomes the only viable alternative for this species because B. vulgaris does not set seed after sparse flowering, which makes seedling progenies unavailable. A low-cost propagation trial was conducted to explore the clonal propagation techniques for the species with two types of small branch cuttings, nodal leafy cuttings and tip cuttings. The cuttings, after treating with 0, 0.1%, 0.4%, and 0.8% IBA solutions, were kept in non-mist propagator to let them to root for assessing the rooting ability. The cuttings were rooted in four weeks and were allowed to grow in the polybags for 10 months under nursery condition to assess their steckling capacity. The study reveals that both types of branch cuttings are able to develop roots, shoots, to survive and to form rhizome under the nursery condition. Rooting ability of the cuttings was significantly enhanced by the application of rooting hormone - IBA. The highest rooting percentage in nodal leafy cuttings and the tip cuttings （56.67% and 51.0%, respectively） were observed in 0.8% IBA treatment, followed by 0.4% IBA and the lowest （34.3% and 30.0%, respectively） was in control. The highest number of root developed per cutting （9.77 and 8.33 in nodal leafy cuttings and the tip cuttings, respectively） was also obtained from the cuttings treated with 0.8% IBA solution, followed 0.4% IBA treatment and the lowest （3.1 and 2.1, respectively） was in the cuttings without treatment. However, the length of the longest root varied significantly neither with the cutting types nor the concentrations of IBA solution. Survival percentage of the stecklings in nursery condition was significantly enhanced by IBA.展开更多
In the last decade there has been a considerable effort to better understand the joint evolution of mafic and ultramafic magmatic systems and their deep mantle roots,through integrated petrological and thermo-barometr...In the last decade there has been a considerable effort to better understand the joint evolution of mafic and ultramafic magmatic systems and their deep mantle roots,through integrated petrological and thermo-barometric studies.Magma generation is regarded as the result of complex processes including melting,creation of channels for melt transfer,and interaction with the wall-rocks.展开更多
The architectural analysis of the young date palm （Phoenix dactylifera L.） root system （its form and its structure）, is necessary to describe its principal functions of absorption and anchoring. In this study the ...The architectural analysis of the young date palm （Phoenix dactylifera L.） root system （its form and its structure）, is necessary to describe its principal functions of absorption and anchoring. In this study the authors present an analysis of the root branching process. It allows them to understand the distribution of inter-lateral root length on the radicle and to account the development of the root system in the soil. Root architecture was studied from samples sprouted naturally in the oases of Chott el Ferikh （Gabes） and other plants grown in polyethylene bags under the shadow. This analysis has showed five categories of roots belonging to four different topological orders in the youthful phasis.展开更多
基金Supported by Key Projects in the National Science&Technology Pillar Program(2011BA107B05-2)~~
文摘Objective] In order to improve the survival rate of Hippophae rhamnoides hardwood cuttings, cultivate high-quality sea buckthorn seedlings. [Method] This pa-per took hard branches of Russian big fruit H. rhamnoides as material. The days of striking roots, rate of striking roots,root length and number of adventitious root were determined. [Result] The cuttings col ected from upper treetops were obviously inferi-or to the lower ones. Three years cutting is obviously better than one or two years. Cuttings from lower branches were not so good as the cuttings from upper branch-es. Base oblique incisions were clearly superior to paper-cover incision. The optimal length of cuttings was 20-25 cm. The rooting rate of cuttings was the highest by fast dipping with NAA of 50 mg/L. [Conclusion] The study provides theoretical basis for H. rhamnoides artificial cultivation.
基金financially supported by the Fundamental Research Funds for the Central Universities(No.YX2010-20)the National Natural Science Foundation of China(No.31570708,No.30901162)the Open Projects Foundation of Key Laboratory of Soil and Water Conservation&Desertification Combat(Beijing Forestry University),Ministry of Education of China(No.201002)
文摘Roots play an important role in stabilizing and strengthening soil. This article aims to study the mechanical properties of the interface between soil and roots with branches, using the pullout test method in the laboratory. The mechanical properties of the soil-root with branches interface is determined through the pullout-force and root-slippage curve （F-S curve）. The results of investigating 24 Pinus tabulaeformis single roots and 55 P. tabulaeformis roots with branches demonstrated three kinds of pullout test failures： breakage failure on branching root, breakage failure on branching node, and pullout failure. The branch angle had a remarkable effect on the failure mode of the roots with branches： the maximum pullout force increased with the sum of the branch diameters and the branch angle. The peak slippage and the initial force had a positive correlation with the sum of the branch diameter. The sig- nificance test of correlation between branch angle and the initial force, however, showed they had no correlation. Branch angle and branch root diameter affect the anchorage properties between root system and soil. Therefore, it is important to investigate the anchorage mechanics of the roots with branches to understand the mechanism of root reinforcement and anchorage.
基金supported by Indian Council ofForestry Research and Education (ICFRE), Dehradun, 248 006, Uttarakhand, India
文摘Dalbergia sissoo Roxb. is one of the promising multipurpose tree species of South Asia. Most of the plantations of D. sissoo from seeds are facing severe threats due to the die-back disease, which ultimately causes death of this potential tree-species within a few months. Vegetative propagation could avoid the die-back disease. Thirty mother trees of different age-groups of D. sissoo were selected for evaluating the rooting behaviour of branch cuttings from D. sissoo as influenced by auxins （IAA or IBA at 100, 200, 500 mg·L^-1）, ages of mother trees （10, 4 and 2 years old） and different environment conditions, i.e., different mediums （soil and sand） or light conditions （in shade and open condition）. The results show that application of IAA and IBA induced more numbers of cuttings （collected from 10-year-old mother trees） to root compared to control. Branch cuttings of D. sissoo collected from 10-year-old mother trees and planted in soil bed in open conditions had 100.0% of cuttings to root in IAA （100 mg·L^-1） and IBA （200 mg·L^-1） treatments. Both rooting medium （Soil and sand） influenced significantly （p〈0.05） on rooting response of branch cuttings. Soil medium was found to achieve maximum no. of branch cuttings to root, compared to sand medium.
基金funded by the National Natural Science Foundation of China(Nos.32071745,31870602,31800519 and 31901295)Program of Sichuan Excellent Youth Sci-Tech Foundation(No.2020JDJQ0052)the National Key Research and Development Program of China(Nos.2016YFC0502505and 2017YFC0505003)。
文摘Background:The terminal branch orders of plant root systems are increasingly known as an ephemeral module.This concept is crucial to recognize belowground processes.However,it is unknown if root modules still exist after they die?Methods:The decomposition patterns of the first five root orders were observed for 3 years using a branch-order classification,a litter-bag method and sequential sampling in a common subalpine tree species(Picea asperata)of southwestern China.Results:Two root modules were observed during the 3-year incubation.Among the first five branch orders,the first three order roots exhibited temporal patterns of mass loss,nutrients and stoichiometry distinct from their woody mother roots throughout the experimental period.This study,for the first time,reported the decomposition pattern of each individual root order and found a similar decomposition dynamic among ephemeral root branches in a forest tree species.Conclusions:Results from this study suggest that root modules may also exist after death,while more data are needed for confirmation.The findings may further advance our understanding of architecture-associated functional heterogeneity in the fine-root system and also improve our ability to predict belowground processes.
文摘Bambusa vulgaris Schrad ex wendl is a widely cultivated bamboo species in rural Bangladesh for its versatile uses. The vegetative propagation becomes the only viable alternative for this species because B. vulgaris does not set seed after sparse flowering, which makes seedling progenies unavailable. A low-cost propagation trial was conducted to explore the clonal propagation techniques for the species with two types of small branch cuttings, nodal leafy cuttings and tip cuttings. The cuttings, after treating with 0, 0.1%, 0.4%, and 0.8% IBA solutions, were kept in non-mist propagator to let them to root for assessing the rooting ability. The cuttings were rooted in four weeks and were allowed to grow in the polybags for 10 months under nursery condition to assess their steckling capacity. The study reveals that both types of branch cuttings are able to develop roots, shoots, to survive and to form rhizome under the nursery condition. Rooting ability of the cuttings was significantly enhanced by the application of rooting hormone - IBA. The highest rooting percentage in nodal leafy cuttings and the tip cuttings （56.67% and 51.0%, respectively） were observed in 0.8% IBA treatment, followed by 0.4% IBA and the lowest （34.3% and 30.0%, respectively） was in control. The highest number of root developed per cutting （9.77 and 8.33 in nodal leafy cuttings and the tip cuttings, respectively） was also obtained from the cuttings treated with 0.8% IBA solution, followed 0.4% IBA treatment and the lowest （3.1 and 2.1, respectively） was in the cuttings without treatment. However, the length of the longest root varied significantly neither with the cutting types nor the concentrations of IBA solution. Survival percentage of the stecklings in nursery condition was significantly enhanced by IBA.
文摘In the last decade there has been a considerable effort to better understand the joint evolution of mafic and ultramafic magmatic systems and their deep mantle roots,through integrated petrological and thermo-barometric studies.Magma generation is regarded as the result of complex processes including melting,creation of channels for melt transfer,and interaction with the wall-rocks.
文摘The architectural analysis of the young date palm （Phoenix dactylifera L.） root system （its form and its structure）, is necessary to describe its principal functions of absorption and anchoring. In this study the authors present an analysis of the root branching process. It allows them to understand the distribution of inter-lateral root length on the radicle and to account the development of the root system in the soil. Root architecture was studied from samples sprouted naturally in the oases of Chott el Ferikh （Gabes） and other plants grown in polyethylene bags under the shadow. This analysis has showed five categories of roots belonging to four different topological orders in the youthful phasis.
