• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 4
  • 3
  • 1
  • Tagged with
  • 8
  • 8
  • 4
  • 4
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Genetic diversity of Vetiver clones (Chrysopogon zizanioides and Chrysopogon nigritana) available in South Africa based on sequencing analyses and anatomical structure / Vickey Diedericks

Diedericks, Vickey January 2014 (has links)
Vetiver grass or Chrysopogon zizanioides (L.) Roberty (1960) is a sterile grass which can regenerate vegetatively from clumps of the rootstock. This, as well as its vigorous and deep root system and flood tolerance makes it an ideal candidate for the use in soil remediation and erosion control. In South Africa, Hydromulch (Pty) Ltd. is part of the landscape, soil reclamation and erosion control industry. The company uses vetiver grass on a wide scale and has accumulated a collection of isolates to serve as possible germ lines for industrial use. Due to the different approaches in environmental management as well as environmental factors, a variety of ecotypes form during the planting and acclimatisation of this genus. Chrysopogon nigritanus (Benth.) Veldkamp (1999), which is a native species to Africa, is closely related to C. zizanioides and differs only slightly from C. zizanioides on a morphological level. The major difference between the two species is that C. nigritanus is able to seed freely and thus the use of this species should be avoided. The need arose to screen other non-fertile plants to uncover additional genotypic variety to enable diversification of vetiver plantings. The aim of this study was to characterise the genotype of 19 isolates of vetiver obtained from Hydromulch (Pty) Ltd. via sequencing analyses of three DNA fragments, ITS, ndhF and rbcL. In addition, the radial root anatomy was also investigated and compared with the genetic analyses. According to the results generated during this study, very little or no genotypical differences exist amongst the different isolates available from the Hydromulch (Pty) Ltd. plant collection. Only in the case of the ITS inference were differences observed between three of the studied isolates. There was no significant difference between the different isolates based on the root anatomy, with the exception of two of the studied isolates which formed starch granules. / MSc (Botany), North-West University, Potchefstroom Campus, 2014
2

Genetic diversity of Vetiver clones (Chrysopogon zizanioides and Chrysopogon nigritana) available in South Africa based on sequencing analyses and anatomical structure / Vickey Diedericks

Diedericks, Vickey January 2014 (has links)
Vetiver grass or Chrysopogon zizanioides (L.) Roberty (1960) is a sterile grass which can regenerate vegetatively from clumps of the rootstock. This, as well as its vigorous and deep root system and flood tolerance makes it an ideal candidate for the use in soil remediation and erosion control. In South Africa, Hydromulch (Pty) Ltd. is part of the landscape, soil reclamation and erosion control industry. The company uses vetiver grass on a wide scale and has accumulated a collection of isolates to serve as possible germ lines for industrial use. Due to the different approaches in environmental management as well as environmental factors, a variety of ecotypes form during the planting and acclimatisation of this genus. Chrysopogon nigritanus (Benth.) Veldkamp (1999), which is a native species to Africa, is closely related to C. zizanioides and differs only slightly from C. zizanioides on a morphological level. The major difference between the two species is that C. nigritanus is able to seed freely and thus the use of this species should be avoided. The need arose to screen other non-fertile plants to uncover additional genotypic variety to enable diversification of vetiver plantings. The aim of this study was to characterise the genotype of 19 isolates of vetiver obtained from Hydromulch (Pty) Ltd. via sequencing analyses of three DNA fragments, ITS, ndhF and rbcL. In addition, the radial root anatomy was also investigated and compared with the genetic analyses. According to the results generated during this study, very little or no genotypical differences exist amongst the different isolates available from the Hydromulch (Pty) Ltd. plant collection. Only in the case of the ITS inference were differences observed between three of the studied isolates. There was no significant difference between the different isolates based on the root anatomy, with the exception of two of the studied isolates which formed starch granules. / MSc (Botany), North-West University, Potchefstroom Campus, 2014
3

Anatomia em Velloziaceae: caracteres, evolução e filogenia / Anaromy in Velloziaceae: charactes, evolution and phylogeny

Cattai, Marina Blanco 04 May 2007 (has links)
Em Velloziaceae, a delimitação da família, subfamílias e gêneros é bastante controversa e as filogenias existentes são mal sustentadas. Considerando que os estudos anatômicos são extremamente importantes na delimitação de novas espécies, na classificação e em análises cladísticas de Velloziaceae, o presente trabalho tem como objetivo ampliar o conhecimento anatômico da raiz, do caule e da folha. Através de secções anatômicas e dissociação do xilema de vinte e cinco espécies da família e três representantes do grupo externo (Bromeliaceae, Cyclanthaceae e Pandanaceae) visa buscar novos caracteres a serem incorporados em análises cladísticas. O estudo dos elementos traqueais evidenciou a presença de placa de perfuração simples na raiz e uma grande diversidade de formas de elementos traqueais no caule, já que é possível observar, em uma mesma espécie, desde traqueídes muito longas, até elementos de vaso muito curtos. À exceção de Acanthochlamys bracteata, todas as espécies analisadas possuem traqueídes no caule, característica que confere vantagens às plantas que sofrem estresses uma vez que são mais resistentes à cavitação. Na folha, à exceção de Talbotia elegans que possui apenas traqueídes, todas as espécies da família apresentam elementos de vaso com placa de perfuração escalariforme. O estudo dos elementos traqueais apontou quatro novos caracteres e a análise das secções transversais e longitudinais radiculares e caulinares levantou mais oito caracteres referentes à características do córtex da raiz e do caule, forma da secção transversal caulinar, presença de feixe fibroso central e feixes vasculares caulinares, a serem incorporados em análises cladísticas baseadas em dados morfológicos e combinada para a família. A hipótese filogenética obtida revelou que, dos doze caracteres analisados, seis constituem sinapomorfias de Velloziaceae incluindo Acanthochlamys bracteata, duas delas homoplásticas. Além disso, uma sinapomorfia para o clado (Nanuza Vellozia) e uma para Vellozia s.s. emergiram na análise. A hipótese filogenética obtida sustenta a inclusão de A. bracteata em Velloziaceae, a delimitação de Barbacenia e Vellozia proposta por Mello-Silva, e a delimitação de Smith & Ayensu para as subfamílias de Velloziaceae s.s. / The classification for family, subfamilies and genera of the Velloziaceae is controversial and the existing phylogenies are poorly supported. Considering that anatomical features are widely used in the definition of new species, classification and cladistic analyses, this paper provides a better understanding of the root, stem and leaf anatomy of the Velloziaceae. Through transverse and longitudinal sections as well as xylem maceration of 25 species of Velloziaceae and three from outgroups (Bromeliaceae, Cyclanthaceae and Pandanaceae), a search of new morphological characters to be added in cladistic analyses was performed. The xylem analyses showed that all Velloziaceae have simple perforation plates in roots and a huge diversity of tracheary elements in stems including long tracheids to small vessel elements in a single species. Except for Acanthochlamys bracteata, all species present tracheids in stems, an important feature to plants that survive dry periods of several months because they can prevent cavitation. In leaves, except for Talbotia elegans that possesses only tracheids, all Velloziaceae have vessel elements with scalariform perforation plates. The analysis of tracheary elements provided four new characters. The anatomical studies produced another eight characters referring to the characteristics of the cortex of the root and stem, form of the transverse stem section, presence of a central, fibrous vascular bundle and stem vascular bundles. All of these new characters were added to morphological and combined analyses of Velloziaceae. The cladistic analysis showed that six of the 12 characters described here are synapomorphies for Velloziaceae, including Acanthochlamys bracteata, although two are homoplastic. Furthermore, one synapomorphy of the Nanuza- Vellozia clade and one of Vellozia s.s. emerged in the analysis. This phylogenetic hypothesis supports the inclusion of A. bracteata in Velloziaceae, the delimitation of Barbacenia and Vellozia as proposed by Mello-Silva, and the recognition of the subfamilies of Velloziaceae s.s. as described by Smith & Ayensu.
4

Anatomia em Velloziaceae: caracteres, evolução e filogenia / Anaromy in Velloziaceae: charactes, evolution and phylogeny

Marina Blanco Cattai 04 May 2007 (has links)
Em Velloziaceae, a delimitação da família, subfamílias e gêneros é bastante controversa e as filogenias existentes são mal sustentadas. Considerando que os estudos anatômicos são extremamente importantes na delimitação de novas espécies, na classificação e em análises cladísticas de Velloziaceae, o presente trabalho tem como objetivo ampliar o conhecimento anatômico da raiz, do caule e da folha. Através de secções anatômicas e dissociação do xilema de vinte e cinco espécies da família e três representantes do grupo externo (Bromeliaceae, Cyclanthaceae e Pandanaceae) visa buscar novos caracteres a serem incorporados em análises cladísticas. O estudo dos elementos traqueais evidenciou a presença de placa de perfuração simples na raiz e uma grande diversidade de formas de elementos traqueais no caule, já que é possível observar, em uma mesma espécie, desde traqueídes muito longas, até elementos de vaso muito curtos. À exceção de Acanthochlamys bracteata, todas as espécies analisadas possuem traqueídes no caule, característica que confere vantagens às plantas que sofrem estresses uma vez que são mais resistentes à cavitação. Na folha, à exceção de Talbotia elegans que possui apenas traqueídes, todas as espécies da família apresentam elementos de vaso com placa de perfuração escalariforme. O estudo dos elementos traqueais apontou quatro novos caracteres e a análise das secções transversais e longitudinais radiculares e caulinares levantou mais oito caracteres referentes à características do córtex da raiz e do caule, forma da secção transversal caulinar, presença de feixe fibroso central e feixes vasculares caulinares, a serem incorporados em análises cladísticas baseadas em dados morfológicos e combinada para a família. A hipótese filogenética obtida revelou que, dos doze caracteres analisados, seis constituem sinapomorfias de Velloziaceae incluindo Acanthochlamys bracteata, duas delas homoplásticas. Além disso, uma sinapomorfia para o clado (Nanuza Vellozia) e uma para Vellozia s.s. emergiram na análise. A hipótese filogenética obtida sustenta a inclusão de A. bracteata em Velloziaceae, a delimitação de Barbacenia e Vellozia proposta por Mello-Silva, e a delimitação de Smith & Ayensu para as subfamílias de Velloziaceae s.s. / The classification for family, subfamilies and genera of the Velloziaceae is controversial and the existing phylogenies are poorly supported. Considering that anatomical features are widely used in the definition of new species, classification and cladistic analyses, this paper provides a better understanding of the root, stem and leaf anatomy of the Velloziaceae. Through transverse and longitudinal sections as well as xylem maceration of 25 species of Velloziaceae and three from outgroups (Bromeliaceae, Cyclanthaceae and Pandanaceae), a search of new morphological characters to be added in cladistic analyses was performed. The xylem analyses showed that all Velloziaceae have simple perforation plates in roots and a huge diversity of tracheary elements in stems including long tracheids to small vessel elements in a single species. Except for Acanthochlamys bracteata, all species present tracheids in stems, an important feature to plants that survive dry periods of several months because they can prevent cavitation. In leaves, except for Talbotia elegans that possesses only tracheids, all Velloziaceae have vessel elements with scalariform perforation plates. The analysis of tracheary elements provided four new characters. The anatomical studies produced another eight characters referring to the characteristics of the cortex of the root and stem, form of the transverse stem section, presence of a central, fibrous vascular bundle and stem vascular bundles. All of these new characters were added to morphological and combined analyses of Velloziaceae. The cladistic analysis showed that six of the 12 characters described here are synapomorphies for Velloziaceae, including Acanthochlamys bracteata, although two are homoplastic. Furthermore, one synapomorphy of the Nanuza- Vellozia clade and one of Vellozia s.s. emerged in the analysis. This phylogenetic hypothesis supports the inclusion of A. bracteata in Velloziaceae, the delimitation of Barbacenia and Vellozia as proposed by Mello-Silva, and the recognition of the subfamilies of Velloziaceae s.s. as described by Smith & Ayensu.
5

Anatomia do caule e da raiz em Menispermaceae\" / Stem and root anatomy in Menispermaceae

Tamaio, Neusa 20 December 2006 (has links)
Menispermaceae é uma família de distribuição pantropical que compreende diversos hábitos, em sua maioria, trepadeiras herbáceas e lianas, além de ervas, arbustos e árvores e onde se faz presente a variação cambial do tipo câmbios sucessivos. Este trabalho apresenta um estudo anatômico do caule e da raiz com ênfase nas lianas e trepadeiras herbáceas. Estudou-se 10 gêneros, 14 espécies e 31 espécimes. Cinco espécies são trepadeiras herbáceas, uma é herbácea (Cissampelos ovalifolia), uma é arbustiva (Abuta grandifolia), e o restante são lianas. As lianas e o arbusto apresentam em seus caules, a variação cambial do tipo câmbios sucessivos, enquanto as trepadeiras herbáceas e a erva não apresentam essa variação estrutural. Demonstra-se na liana Abuta imene, de maneira inédita para a família, que o periciclo origina o tecido conjuntivo, e esse, por sua vez, os câmbios sucessivos. Na análise comparativa do xilema secundário em diversos anéis sucessivos contidos no mesmo caule, destaca-se que o lenho produzido pelos novos anéis vasculares, normalmente, não difere qualitativamente do anel vascular original, no entanto há diferenças quando aos caracteres quantitativos: os diâmetros dos elementos de vasos sofreram aumento estatisticamente significativo no sentido centro-periferia. A análise do caule entre dois hábitos de Abuta grandifolia (liana X arbusto) mostrou que ambos possuem o mesmo padrão anatômico, porém, destaca-se que os diâmetros de elementos de vasos são menores no arbusto. Variações quantitativas ocorrem entre o lenho de caule e a raiz de trepaderias herbáceas e estão relacionadas ao diâmetro e comprimento dos elementos de vasos que são maiores nos caules. Alguns dados são relatados, pela primeira vez, para essa família: (1) Classifica-se o sistema subterrâneo de Disciphania hernandia como raiz tuberosa; (2) Ruptura do raio vascular através da transformação de iniciais radiais em iniciais fusiformes no xilema e floema; (3) A constatação de câmbios sucessivos na raiz da liana Chondrodendron platiphyllum. Apesar da similaridade quanto à estrutura anatômica geral do caule, existem caracteres que separam as trepadeiras herbáceas das lianas, tais como: o tipo de parênquima, morfologia dos cristais, o diâmetro e a distribuição dos elementos de tubos crivados e a transformação das iniciais, tanto fusiformes quanto radiais nas trepadeiras herbáceas. Fornece-se, ainda, alguns aspectos anatômicos do floema secundário no caule. Recomenda-se a padronização de estudos do lenho na família através do primeiro anel. Discute-se a presença de raio medular na família. Conclui-se que os caules das lianas são muito similares, portanto, a identificação das porções do lenho utilizadas em objetos comercializados somente é possível ao nível de família. / The pantropical family Menispermaceae includes several habits, like herbaceous vines, herbs, shrubs, and trees, showing cambial variant of successive type. The present study is an anatomical approach of stem and root of woody and herbaceous vine habits. In the present study, 31 specimens were investigated, sampling 10 genera and 14 species. Of those species, five are herbaceous vines, one is herb (Cissampelos ovalifolia) and one is shrub (Abuta grandifolia), and the rest are woody vines. Stems of woody vines and shrubs show successive cambia, not assigned to herbs and herbaceous vines. For the first time in the family, it is observed in the woody vine Abuta imene that the conjunctive tissue originates from the pericycle, and that the successive cambia, on its turn, originates from the conjunctive tissue. In the comparative analysis of secondary xylem in its several successive rings in the same stem, the wood produced by new vascular rings does not differ qualitatively from the original vascular ring, while there are differences in quantitative characters: diameter of vessel elements show significant increase in centreperiphery direction. The stem analysis between two habits of Abuta grandifolia (woody vine X shrub) shows that both have the same anatomical pattern. However, diameter of vessel elements is smaller in shrubs. Quantitative variation occurs between stem and root in herbaceous vine wood, and are related to diameter and length of vessel elements, which are larger in stems. Some data are described for the family for the first time: (1) The subterranean system of Disciphania hernandia is assigned as root tuber; (2) Splitting of ray by transformation of ray initials to fusiform initials in xylem and phloem; (3) Presence of successive cambia in woody vine root of Chondrodendron platiphyllum. Despite the anatomical general resemblance of stem, there are characters that distinguish herbaceous from woody vines, like: the kind of parenchyma, crystal morphology, diameter and distribution of sieve tube elements, and transformation of fusiform and ray initials in herbaceous vines. Additionally, some anatomical aspects of secondary phloem in stem are shown. The standardization of woody studies in the family considering the first ring is recommended. Discussions are made about the presence of medullary ray in the family. It is concluded that the stem of woody vines are very similar to each other, and thus, identification of woody portions used in commercialized objects is possible only at familial level.
6

Anatomia do caule e da raiz em Menispermaceae\" / Stem and root anatomy in Menispermaceae

Neusa Tamaio 20 December 2006 (has links)
Menispermaceae é uma família de distribuição pantropical que compreende diversos hábitos, em sua maioria, trepadeiras herbáceas e lianas, além de ervas, arbustos e árvores e onde se faz presente a variação cambial do tipo câmbios sucessivos. Este trabalho apresenta um estudo anatômico do caule e da raiz com ênfase nas lianas e trepadeiras herbáceas. Estudou-se 10 gêneros, 14 espécies e 31 espécimes. Cinco espécies são trepadeiras herbáceas, uma é herbácea (Cissampelos ovalifolia), uma é arbustiva (Abuta grandifolia), e o restante são lianas. As lianas e o arbusto apresentam em seus caules, a variação cambial do tipo câmbios sucessivos, enquanto as trepadeiras herbáceas e a erva não apresentam essa variação estrutural. Demonstra-se na liana Abuta imene, de maneira inédita para a família, que o periciclo origina o tecido conjuntivo, e esse, por sua vez, os câmbios sucessivos. Na análise comparativa do xilema secundário em diversos anéis sucessivos contidos no mesmo caule, destaca-se que o lenho produzido pelos novos anéis vasculares, normalmente, não difere qualitativamente do anel vascular original, no entanto há diferenças quando aos caracteres quantitativos: os diâmetros dos elementos de vasos sofreram aumento estatisticamente significativo no sentido centro-periferia. A análise do caule entre dois hábitos de Abuta grandifolia (liana X arbusto) mostrou que ambos possuem o mesmo padrão anatômico, porém, destaca-se que os diâmetros de elementos de vasos são menores no arbusto. Variações quantitativas ocorrem entre o lenho de caule e a raiz de trepaderias herbáceas e estão relacionadas ao diâmetro e comprimento dos elementos de vasos que são maiores nos caules. Alguns dados são relatados, pela primeira vez, para essa família: (1) Classifica-se o sistema subterrâneo de Disciphania hernandia como raiz tuberosa; (2) Ruptura do raio vascular através da transformação de iniciais radiais em iniciais fusiformes no xilema e floema; (3) A constatação de câmbios sucessivos na raiz da liana Chondrodendron platiphyllum. Apesar da similaridade quanto à estrutura anatômica geral do caule, existem caracteres que separam as trepadeiras herbáceas das lianas, tais como: o tipo de parênquima, morfologia dos cristais, o diâmetro e a distribuição dos elementos de tubos crivados e a transformação das iniciais, tanto fusiformes quanto radiais nas trepadeiras herbáceas. Fornece-se, ainda, alguns aspectos anatômicos do floema secundário no caule. Recomenda-se a padronização de estudos do lenho na família através do primeiro anel. Discute-se a presença de raio medular na família. Conclui-se que os caules das lianas são muito similares, portanto, a identificação das porções do lenho utilizadas em objetos comercializados somente é possível ao nível de família. / The pantropical family Menispermaceae includes several habits, like herbaceous vines, herbs, shrubs, and trees, showing cambial variant of successive type. The present study is an anatomical approach of stem and root of woody and herbaceous vine habits. In the present study, 31 specimens were investigated, sampling 10 genera and 14 species. Of those species, five are herbaceous vines, one is herb (Cissampelos ovalifolia) and one is shrub (Abuta grandifolia), and the rest are woody vines. Stems of woody vines and shrubs show successive cambia, not assigned to herbs and herbaceous vines. For the first time in the family, it is observed in the woody vine Abuta imene that the conjunctive tissue originates from the pericycle, and that the successive cambia, on its turn, originates from the conjunctive tissue. In the comparative analysis of secondary xylem in its several successive rings in the same stem, the wood produced by new vascular rings does not differ qualitatively from the original vascular ring, while there are differences in quantitative characters: diameter of vessel elements show significant increase in centreperiphery direction. The stem analysis between two habits of Abuta grandifolia (woody vine X shrub) shows that both have the same anatomical pattern. However, diameter of vessel elements is smaller in shrubs. Quantitative variation occurs between stem and root in herbaceous vine wood, and are related to diameter and length of vessel elements, which are larger in stems. Some data are described for the family for the first time: (1) The subterranean system of Disciphania hernandia is assigned as root tuber; (2) Splitting of ray by transformation of ray initials to fusiform initials in xylem and phloem; (3) Presence of successive cambia in woody vine root of Chondrodendron platiphyllum. Despite the anatomical general resemblance of stem, there are characters that distinguish herbaceous from woody vines, like: the kind of parenchyma, crystal morphology, diameter and distribution of sieve tube elements, and transformation of fusiform and ray initials in herbaceous vines. Additionally, some anatomical aspects of secondary phloem in stem are shown. The standardization of woody studies in the family considering the first ring is recommended. Discussions are made about the presence of medullary ray in the family. It is concluded that the stem of woody vines are very similar to each other, and thus, identification of woody portions used in commercialized objects is possible only at familial level.
7

Строение корней осок из местообитаний с разной степенью увлажнения : магистерская диссертация / Structure of sedge roots from hab-its with different degrees of humidification

Тукова, Д. Е., Tukova, D. E. January 2021 (has links)
Магистерская диссертация на тему «СТРОЕНИЕ КОРНЕЙ ОСОК ИЗ МЕСТООБИТАНИЙ С РАЗНОЙ СТЕПЕНЬЮ УВЛАЖНЕНИЯ» состоит из 52 страниц машинописного текста, включая 19 рисунков, 2 таблицы и 113 литературных источников. Работа посвящена изучению морфологического и анатомического строения корней осок из местообитаний с разной степенью увлажнения и разных экоморф, или экологических групп по отношению к увлажнению. В исследованный материал входят собственные сборы и зафиксированные растительные образцы научных руководителей. Цель – изучение строения корней осок из местообитаний с разной степенью увлажнения и разных экоморф по отношению к увлажнению. Задачи: Изучить внешние признаки корневых систем и строение поглощаю-щих корней у осок разных экоморф и местообитаний; Установить, какие признаки и в какой степени связаны с экоморфой видов, а какие изменяются под действием режима увлажнения местообитаний независимо от принадлежности к экоморфе. Растения собраны в начале июня в период цветения большинства исследован-ных видов 2019-2021 гг. в местообитаниях, образующих градиент по увлажнению: водоем-луг-лес-сухой склон. Экологические группы по степени увлажнения среды (гигрофиты, мезофиты, ксеромезофиты) выделены по литературному источнику [Овеснов и др., 2007]. С помощью стандартных методик структурной ботаники изучены внешние признаки корневых систем и строение поглощающих корней 23 вида осок. Регистрировали параметры: число порядков ветвления корней, тип волосков, длина типичных волосков, диаметр корня; диаметр стелы; толщину паренхимы; число слоев клеток в паренхиме; число слоев клеток в экзодерме, толщину коры. Расчетные показатели – парциальный объем коры и стелы, %. В работе представлены 2 способа формирования учетных единиц. При анализе экологических групп, учетной единицей считается вид. Исследуя группы осок из местообитаний с разной степенью увлажнения, учетной единицей считается особь. Статистический анализ проводился с помощью программы STATISTICA 10. Использовали однофакторный дисперсионный анализ (F) (ANOVA) Непараметриче-ские критерии Краскела –Уоллиса (H) и Критерий (χ2) Пирсона. Результаты магистерской диссертации показали, что признаками тонких корней изученных осок, наиболее чувствительными к режиму увлажнения, являются: число порядков ветвления корней; встречаемость выпуклых корневых волосков; длина типичных корневых волосков; диаметр среза, толщина коры; выраженность экзодермы; У изученных осок от переувлажненных местообитаний к засушливым: а) увеличивается число порядков ветвления корней; б) уменьшаются: встречаемость выпуклых корневых волосков, длина корневых волосков, диаметр среза, толщина первичной коры за счет уменьшения слоев экзодермы. Несмотря на таксоноспецифичное строения корней осок, существует явно выраженная экологическая пластичность ряда признаков внутри обширного рода Carex. Полученные результаты согласуются с опубликованными данными. Результаты были представлены в устном докладе на Всероссийской конференции молодых ученых «Экология: факты, гипотезы, модели», проходившей в апреле 2021 года. Планируется публикация данных в сборнике конференции в виде тезисов. / The master's thesis on the topic "STRUCTURE OF SEDGE ROOTS FROM HAB-ITS WITH DIFFERENT DEGREES OF HUMIDIFICATION" consists of 52 pages of typewritten text, including 19 figures, 2 tables and 113 literature sources. The work is devoted to the study of the morphological and anatomical structure of sedge roots from habitats with varying degrees of moisture and different ecological groups. The analysis of the work consists of materials from our collection and recorded plant material [Konoplenko et al., 2017]. The goal is to study the structure of sedge roots from habitats with varying degrees of moisture and different ecomorphs in relation to moisture. Tasks: 1) To study the external signs of root systems and the structure of absorbing roots in sedges of different ecomorphs and habitats; 2) Establish which features and to what extent are associated with the ecomorph of the species, and which ones change under the influence of the habitat moistening regime, regardless of belonging to the ecomorph. To tackle these problems, the plants were collected in habitats forming a moisture gradient: reservoir-meadow-forest-dry slope. The ecological groups of sedge species were identified according to the literature [Ovesnov et al., 2007] according to the degree of en-vironmental moisture: hygrophytes, mesophytes, Xeromesophytes. Using the methods of structural botany, the external signs of root systems and the structure of absorbing roots of 23 species of sedges were studied. The following parameters were recorded: the number of orders of root branching, hair type, length of typical hairs, root diameter; stele diameter; parenchyma thickness; the number of cell layers in the parenchyma; the number of cell layers in the exoderm, the thickness of the cortex. Integral indicators - the partial volume of the cortex and ste-le,%. Statistical analysis was carried out using the STATISTICA 10 program. One-way analysis of variance (F) (ANOVA) was used. Nonparametric Kruskal-Wallis tests (H) and Pearson's test (χ2). The results of the master's thesis showed that the features of the thin roots of the studied sedges, the most sensitive to the moisture regime, are:the number of orders of root branching; the occurrence of convex root hairs; length of typical root hairs; cut diameter, bark thickness; the severity of exoderm; In the studied sedges, from waterlogged to arid habitats: a) the number of orders of branching of roots increases; b) decrease: the occurrence of convex root hairs, length of root hairs, cut diameter, thickness of the primary cortex due to a decrease in exoderm layers. Despite the taxon-specific structure of sedge roots, there is a pronounced ecological plasticity of a number of characters within the vast genus Carex. The results obtained are consistent with published data. These results were presented in an oral report at the All-Russian Conference of Young Scientists "Ecology: Facts, Hypotheses, Models", held in April 2021. It is planned to publish data in the conference collection in the form of abstracts.
8

Intra- and interspecific variation of functional traits, growth performance and belowground competition in <i>Populus</i> species

Hajek, Peter 27 March 2014 (has links)
No description available.

Page generated in 0.0465 seconds