[目的]分析海南典型热带山地雨林分布区域尖峰岭60 hm^(2)大样地内豆科树种对邻体树木的影响,并探讨其可能的影响机制。[方法]利用尖峰岭60 hm^(2)大样地的2012年和2018年2次调查数据,对样地内7种豆科树木的邻体非豆科树木的多度、丰富...[目的]分析海南典型热带山地雨林分布区域尖峰岭60 hm^(2)大样地内豆科树种对邻体树木的影响,并探讨其可能的影响机制。[方法]利用尖峰岭60 hm^(2)大样地的2012年和2018年2次调查数据,对样地内7种豆科树木的邻体非豆科树木的多度、丰富度和存活率进行比较分析。[结果]2次调查期间,7种豆科树木的邻体多度和丰富度无显著变化。与非豆科树木相比,软荚红豆(Ormosia semicastrata Hance)、猴耳环(Archidendron clypearia(Jack)I.C.Nielsen)和亮叶猴耳环(A.lucidum(Benth.)Nielsen)具有较高的邻体多度和丰富度,而肥荚红豆(O.fordiana Oliv.)、木荚红豆(O.xylocarpa Chun ex L.Chen)、长脐红豆(O.blansae Drake)和薄叶猴耳环(A.utile Chun et How)具有较低的邻体多度和丰富度。软荚红豆、肥荚红豆和猴耳环具有较高的邻体树木的存活率,而长脐红豆、薄叶猴耳环、亮叶猴耳环和木荚红豆具有较低的邻体树木的存活率;7种豆科树木对邻体多度、丰富度的影响与其叶片氮含量和固氮能力无显著相关关系,但邻体距离为4 m的豆科树木邻体存活率与叶片氮含量有显著相关关系。[结论]总体上,不同豆科树木对邻体的影响不尽相同,软荚红豆更倾向于对邻体产生有利作用,薄叶猴耳环和木荚红豆对邻体产生抑制作用,而其它4种豆科树木对邻体的多度、丰富度和存活率的影响不一致。展开更多
Proteolysis of seed storage proteins (SSP) during germination provides a steady supply of amino acids to the embryo development into seedling. This process is coordinated by different peptidases that act sequentially ...Proteolysis of seed storage proteins (SSP) during germination provides a steady supply of amino acids to the embryo development into seedling. This process is coordinated by different peptidases that act sequentially and overlaid mode. These enzymes are an ancient group evolved separately in a wide structural and functional diversity and have many applications in medicine, pharmacy and industry. However, the knowledge about seed peptidases during germination was obtained from studies almost restricted to the cultivated species. This restriction implies caution about generalizations made from these studies, as well limits the biological knowledge about plant kingdom and technological use from plant peptidases. In this work, a scan of the proteolytic activity was held in germinating seeds of a leguminous subtropical woody tree. Eleven proteolytic activities were detected in protein extracts from embryonic axis and cotyledons. The presence and intensity of these activities varied over time and between these tissues. There was indication that aspartyl-endopeptidases (phytepsins) and cysteine-carboxypeptidases (plant cathepsins) were involved in A. colubrina SSP hydrolysis. These peptidases differ to that commonly involved in germination of the cultivated leguminous. In addition, one of detected phytepsins showed stability on pH scale, which is important for industrial uses. There was also detected a metallo-carboxypeptidase activity, which has been not described in plants. These peptidases must be isolated to confirm or not these indications. However, these data indicate the biological and technological importance of extending the studies about plant peptidases on a diverse genetic basis.展开更多
Soil microbial biomass is an active fraction of soil organic matter. It shows quicker response than soil organic matter to any change in the soil environment. Being an index of soil fertility, it plays a key role in t...Soil microbial biomass is an active fraction of soil organic matter. It shows quicker response than soil organic matter to any change in the soil environment. Being an index of soil fertility, it plays a key role in the decomposition of litters and fast release of available nutrients. Leaf litters of leguminous and non-leguminous species in alone and mixed form were applied as treatments in the soil to observe the changes in the magnitude of soil microbial biomass. Soil microbial biomass C and N were determined by chloroform fumigation extraction method. Increment in the concentration of microbial biomass C and N was higher in the treatments with leguminous leaf litter (497 - 571 μgCg?1, 48 - 55 μgNg?1) than the non-leguminous one (256 - 414 μgCg?1;22 - 36 μgNg?1). However, when non-leguminous litters were mixed with leguminous litters then the values increased distinctly (350 - 465 μgCg?1, 28 - 48 μgNg?1). On the basis of increment in soil microbial biomass, leaf litters of the species considered potential to improve soil nutrients are—Cassia siamea and Dalbergia sissoo from leguminous trees, Anthocephalus + Cassia and Shorea + Dalbergia from mixed form of non-leguminous and leguminous one and Eichhornia crassipes, an alien aquatic macrophyte. The leaf litters of these species can be used as source of organic matter to improve the crop yield.展开更多
Acacia seyal is a leguminous plant that plays an important role in the ecosystem of Sahelian zone by producing gum, wood and fodder. The growth of A. seyal is subject to many constraints as salinity which can affect t...Acacia seyal is a leguminous plant that plays an important role in the ecosystem of Sahelian zone by producing gum, wood and fodder. The growth of A. seyal is subject to many constraints as salinity which can affect the development of this tree. Therefore, soil microorganisms can help A. seyal to better tolerate the effects of negative environmental stresses. The contribution of arbuscular mycorrhizal fungi (AMF) to the salt tolerance of A. seyal, was evaluated by testing the effects of eight different arbuscular mycorrhizal fungi (AMF) isolates in the performance of A. seyal seedlings subjected to different levels of salinity (0, 340 and 680 mM). The results based on growth parameters of shoot and root parts, shoot mineral N, P, K and Na content as well as survival rates and mycorrhization showed that AMF improved mineral nutrition of A. seyal seedlings during salt stress. The combination between AMF and salinity provided evidence that the efficiency of AMF isolates were variable in improving mineral nutrition and mortality rate for A. seyal seedlings related to the level of salt stress. However, the effects of inoculation were variable depending to the AMF isolate associated with seedlings and the level of salinity, suggesting that interactions between plants and AMF can be modulated by both AMF diversity and the type and level of abiotic factors. Rhizophagus intraradices was more efficient at 680 mM NaCl in plant growth and mineral uptake while Glomus deserticola did not promote a better plant development than most of the other species inoculated to seedlings.展开更多
This study was carried out to assess the relationship of the status of nodulation(i.e., the number of nodules, their shape and size) in root and biomass production of plant growth parameters(i.e., number of leaves, ro...This study was carried out to assess the relationship of the status of nodulation(i.e., the number of nodules, their shape and size) in root and biomass production of plant growth parameters(i.e., number of leaves, root and shoot lengths, root biomass and shoot biomass) in Albizia saman and Leucaena leucocephala. The assessment started 60 days after seeding. The study revealed that nodulation response and biomass production in both species showed significant differences over time(p < 0.05) in all variables except in the root-shoot ratio(oven-dry) of L. leucocephala. The study also showed significant differences(p < 0.05) in nodule formation and biomass production at the end of the study period between the two species except in the number of nodules and leaves and the green root-shoot ratio. There were strong positive correlations between nodule formation and biomass production, i.e., the number of nodules and the age of plants, the number of nodules and leaves, as well as the number of nodules and biomass(root biomass and shoot biomass) in both species. The results obtained using principal component analysis(PCA) and correlation coefficients of the different characteristics of nodulation and biomass production were similar in both species. The PCA showed that shoot biomass(shoot green weight and shoot oven-dry weight) is positively correlated with PC1(with an eigenvalue of 7.50) and root length is positively correlated with PC2(with an eigenvalue of 0.19) in the case of A. saman. In the case of L. leucocephala, the PCA revealed that root biomass(root green weight and root oven-dry weight), shoot biomass and shoot length are also positively correlated with PC1, while nodule formation and the number of leaves are positively correlated with PC2(with an eigenvalue PC1 of 6.92 and PC2 of 0.49).展开更多
文摘[目的]分析海南典型热带山地雨林分布区域尖峰岭60 hm^(2)大样地内豆科树种对邻体树木的影响,并探讨其可能的影响机制。[方法]利用尖峰岭60 hm^(2)大样地的2012年和2018年2次调查数据,对样地内7种豆科树木的邻体非豆科树木的多度、丰富度和存活率进行比较分析。[结果]2次调查期间,7种豆科树木的邻体多度和丰富度无显著变化。与非豆科树木相比,软荚红豆(Ormosia semicastrata Hance)、猴耳环(Archidendron clypearia(Jack)I.C.Nielsen)和亮叶猴耳环(A.lucidum(Benth.)Nielsen)具有较高的邻体多度和丰富度,而肥荚红豆(O.fordiana Oliv.)、木荚红豆(O.xylocarpa Chun ex L.Chen)、长脐红豆(O.blansae Drake)和薄叶猴耳环(A.utile Chun et How)具有较低的邻体多度和丰富度。软荚红豆、肥荚红豆和猴耳环具有较高的邻体树木的存活率,而长脐红豆、薄叶猴耳环、亮叶猴耳环和木荚红豆具有较低的邻体树木的存活率;7种豆科树木对邻体多度、丰富度的影响与其叶片氮含量和固氮能力无显著相关关系,但邻体距离为4 m的豆科树木邻体存活率与叶片氮含量有显著相关关系。[结论]总体上,不同豆科树木对邻体的影响不尽相同,软荚红豆更倾向于对邻体产生有利作用,薄叶猴耳环和木荚红豆对邻体产生抑制作用,而其它4种豆科树木对邻体的多度、丰富度和存活率的影响不一致。
文摘Proteolysis of seed storage proteins (SSP) during germination provides a steady supply of amino acids to the embryo development into seedling. This process is coordinated by different peptidases that act sequentially and overlaid mode. These enzymes are an ancient group evolved separately in a wide structural and functional diversity and have many applications in medicine, pharmacy and industry. However, the knowledge about seed peptidases during germination was obtained from studies almost restricted to the cultivated species. This restriction implies caution about generalizations made from these studies, as well limits the biological knowledge about plant kingdom and technological use from plant peptidases. In this work, a scan of the proteolytic activity was held in germinating seeds of a leguminous subtropical woody tree. Eleven proteolytic activities were detected in protein extracts from embryonic axis and cotyledons. The presence and intensity of these activities varied over time and between these tissues. There was indication that aspartyl-endopeptidases (phytepsins) and cysteine-carboxypeptidases (plant cathepsins) were involved in A. colubrina SSP hydrolysis. These peptidases differ to that commonly involved in germination of the cultivated leguminous. In addition, one of detected phytepsins showed stability on pH scale, which is important for industrial uses. There was also detected a metallo-carboxypeptidase activity, which has been not described in plants. These peptidases must be isolated to confirm or not these indications. However, these data indicate the biological and technological importance of extending the studies about plant peptidases on a diverse genetic basis.
文摘Soil microbial biomass is an active fraction of soil organic matter. It shows quicker response than soil organic matter to any change in the soil environment. Being an index of soil fertility, it plays a key role in the decomposition of litters and fast release of available nutrients. Leaf litters of leguminous and non-leguminous species in alone and mixed form were applied as treatments in the soil to observe the changes in the magnitude of soil microbial biomass. Soil microbial biomass C and N were determined by chloroform fumigation extraction method. Increment in the concentration of microbial biomass C and N was higher in the treatments with leguminous leaf litter (497 - 571 μgCg?1, 48 - 55 μgNg?1) than the non-leguminous one (256 - 414 μgCg?1;22 - 36 μgNg?1). However, when non-leguminous litters were mixed with leguminous litters then the values increased distinctly (350 - 465 μgCg?1, 28 - 48 μgNg?1). On the basis of increment in soil microbial biomass, leaf litters of the species considered potential to improve soil nutrients are—Cassia siamea and Dalbergia sissoo from leguminous trees, Anthocephalus + Cassia and Shorea + Dalbergia from mixed form of non-leguminous and leguminous one and Eichhornia crassipes, an alien aquatic macrophyte. The leaf litters of these species can be used as source of organic matter to improve the crop yield.
文摘Acacia seyal is a leguminous plant that plays an important role in the ecosystem of Sahelian zone by producing gum, wood and fodder. The growth of A. seyal is subject to many constraints as salinity which can affect the development of this tree. Therefore, soil microorganisms can help A. seyal to better tolerate the effects of negative environmental stresses. The contribution of arbuscular mycorrhizal fungi (AMF) to the salt tolerance of A. seyal, was evaluated by testing the effects of eight different arbuscular mycorrhizal fungi (AMF) isolates in the performance of A. seyal seedlings subjected to different levels of salinity (0, 340 and 680 mM). The results based on growth parameters of shoot and root parts, shoot mineral N, P, K and Na content as well as survival rates and mycorrhization showed that AMF improved mineral nutrition of A. seyal seedlings during salt stress. The combination between AMF and salinity provided evidence that the efficiency of AMF isolates were variable in improving mineral nutrition and mortality rate for A. seyal seedlings related to the level of salt stress. However, the effects of inoculation were variable depending to the AMF isolate associated with seedlings and the level of salinity, suggesting that interactions between plants and AMF can be modulated by both AMF diversity and the type and level of abiotic factors. Rhizophagus intraradices was more efficient at 680 mM NaCl in plant growth and mineral uptake while Glomus deserticola did not promote a better plant development than most of the other species inoculated to seedlings.
文摘This study was carried out to assess the relationship of the status of nodulation(i.e., the number of nodules, their shape and size) in root and biomass production of plant growth parameters(i.e., number of leaves, root and shoot lengths, root biomass and shoot biomass) in Albizia saman and Leucaena leucocephala. The assessment started 60 days after seeding. The study revealed that nodulation response and biomass production in both species showed significant differences over time(p < 0.05) in all variables except in the root-shoot ratio(oven-dry) of L. leucocephala. The study also showed significant differences(p < 0.05) in nodule formation and biomass production at the end of the study period between the two species except in the number of nodules and leaves and the green root-shoot ratio. There were strong positive correlations between nodule formation and biomass production, i.e., the number of nodules and the age of plants, the number of nodules and leaves, as well as the number of nodules and biomass(root biomass and shoot biomass) in both species. The results obtained using principal component analysis(PCA) and correlation coefficients of the different characteristics of nodulation and biomass production were similar in both species. The PCA showed that shoot biomass(shoot green weight and shoot oven-dry weight) is positively correlated with PC1(with an eigenvalue of 7.50) and root length is positively correlated with PC2(with an eigenvalue of 0.19) in the case of A. saman. In the case of L. leucocephala, the PCA revealed that root biomass(root green weight and root oven-dry weight), shoot biomass and shoot length are also positively correlated with PC1, while nodule formation and the number of leaves are positively correlated with PC2(with an eigenvalue PC1 of 6.92 and PC2 of 0.49).
