Plant morphology

About: Plant morphology is a research topic. Over the lifetime, 1174 publications have been published within this topic receiving 24418 citations. The topic is also known as: phytomorphology & morphology of higher plants.

De macrocarpaeae grisebach (ex gentianaceis) speciebus novis vi: seed morphology, palynology, an infrageneric classification , and another twenty-three new species largely from colombia

Abstract: A brief survey of seed morphology and palynology in Macrocarpaea is discussed and illustrated by Scanning Electron Microscopy (SEM) photographs. An infrageneric classification is presented where four sections are recognized: sect. Tabacifoliae, sect. Macrocarpaea, sect. Magnolifoliae, and sect. Choriophylla. Another 23 new species, largely from Colombia, are here described and illustrated: Brazil (1): M. illecebrosa; Colombia (14): M. betancuriana, M. callejasii, M. gaudialis, M. gondoloides, M. gravabilis, M. gulosa, M. hilarula, M. jocularis, M. lacrossiformis, M. laudabilis, M. maryae, M. silverstonei, M. umerulus, and M. ypsilocaule; Ecuador (4): M. berryi, M. jactans, M. neillii, and M. voluptuosa; and Peru (4): M. chthonotropa, M. granpajatena, M. quechua, and M. xerantifulva.

Why only tetraploid Solidago gigantea (Asteraceae) became invasive: a common garden comparison of ploidy levels

Abstract: Many studies have compared the growth of plants from native and invasive populations, but few have considered the role of ploidy. In its native range in North America, Solidago gigantea Aiton (Asteraceae) occurs as a diploid, tetraploid and hexaploid, with considerable habitat differentiation and geographic separation amongst these ploidy levels. In the introduced range in Europe, however, only tetraploid populations are known. We investigated the growth performance and life history characteristics of plants from 12 European and 24 North American (12 diploid, 12 tetraploid) populations in a common garden experiment involving two nutrient and two calcium treatments. Twelve plants per population were grown in pots for two seasons. We measured 24 traits related to leaf nutrients, plant size, biomass production and phenology as well as sexual and vegetative reproduction. Native diploid plants had a higher specific leaf area and higher leaf nutrient concentrations than native tetraploids, but tetraploids produced many more shoots and rhizomes. Diploids grown with additional calcium produced less biomass, whereas tetraploids were not affected. European plants were less likely to flower and produced smaller capitulescences than North American tetraploids, but biomass production and shoot and rhizome number did not differ. We conclude that a knowledge of ploidy level is essential in comparative studies of invasive and native populations. While clonal growth is important for the invasion success of tetraploid S. gigantea, its potential was not acquired by adaptation after introduction but by evolutionary processes in the native range.

Induction and identification of polyploidy in basil (Ocimum basilicum L.) medicinal plant by colchicine treatment

Abstract: Basil (Ocimum basilicum) is one of the important medicinal plant species. In order to produce an autotetraploid population of basil (Ocimum basilicum) by colchicine, different concentrations (0.00, 0.05, 0.10, 0.20, 0.50 and 0.75%) and four treatment methods were examined (seed, the growing point of seedlings at the emergence of cotyledone leaves stage and emergence of true two type leaves stage, and root treatment) to determine the best treatment for the induction of tetraploid plants. Autotetraploid plants were produced only by treatment of growing point of seedlings, at the emergence of cotyledone leaves stage, and treatment with 0.5% proved to be the most effective in producing autotetraploids. The induced tetraploids in basil was accompanied by larger stomata and pollen grains, increase in chloroplast number in guard cells and decrease in stomata density, compared to diploid control plants. In order to distinguish the induced colchicine tetraploid plants from the diploids, morphological changes and techniques as stomata size, number of chloroplasts per guard cell, pollen grain diameter and flow cytometry were considered and proved that these methods are suitable, quick and easy methods for identification the ploidy level of Ocimum basilicum in various stages of the plant development of these species and among this methods flow cytometry as found to be the most efficient method for detecting induced changes in ploidy level.

Plant morphological characteristics and resistance to simulated trampling

Abstract: The relationship between responses of plants to trampling and their morphological characteristics was studied in a glasshouse experiment. Thirteen species with four different growth forms were used in this experiment. They were five tussock species.Chloris gayana, Eragrostis tenuifolia, Lolium perenne, Panicum maximum, andSporobolus elongatus; three prostate grasses,Axonopus compressus, Cynodon dactylon, andTrifolium repens, two herbaceous species,Daucus glochidiatus andHypochoeris radicata; and three woody species,Acacia macradenia, Acrotriche aggregata, andSida rhombifolia. These species were subjected to three levels of simulated trampling. For each species, measurements were taken of aboveground biomass, root biomass, leaf length, leaf width, leaf thickness, leaf number, broken leaf number and plant height. Overall, these measurements were greatest in the control plants, moderate in the level of light trampling, and the lowest in the level of heavy trampling. Biomass was used as a basis of the assessment of plant resistance to trampling. Three tussock species,Eragrostis tenuifolia, Lolium perenne, andSporobolus elongatus had a high resistance. Woody and erect herbaceous plants were more intolerant to trampling. There appear to be two processes involved in the reduction of the plant parameters: direct physical damage with portions of the plants detached, and physiological changes, which slow down vegetative growth rates. Plant height was found to be the most sensitive indicator of trampling damage.