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.

Effect of cultivar of white clover on plant morphology during the establishment of mixed pastures under sheep grazing

Abstract: The establishment of white clover from seed is characterised by two distinct morphological growth forms, a seminal tap‐rooted stage with radiating stolon systems lasting 1–2 years, followed by a clonal growth form. Transition of a plant from tap‐rooted to clonal form occurs when the tap root and primary stem axis die, releasing a variable number of stolon systems as independent clonal plants. The purpose of this study was to investigate any effect different cultivars of white clover may have on the morphology of plants during the transition of populations from tap‐rooted to clonal growth form when establishing in mixed pastures based on either perennial ryegrass or tall fescue. Cultivars studied ranged from small‐leafed to large‐leafed cultivars in the order of Prop, Prestige, Demand, Huia, Sustain, Le Bons, Kopu, and Aran. During the tap‐rooted phase there were no differences between cultivars in shoot growth apart from the small‐leafed cultivars (Prop, Prestige, Demand, and Huia) having a highe...

Root-zone temperature effects on photosynthesis, 14C-photoassimilate partitioning and growth of temperate lettuce (Lactuca sativa cv. ‘Panama’) in the tropics

Abstract: The effect of root growth temperature on maximal photosynthetic CO2 assimilation (P max), carbohydrate content, 14C-photoassimilate partitioning, growth, and root morphology of lettuce was studied after transfer of the root system from cool root-zone temperature (C-RZT) of 20 °C to hot ambient-RZT (A-RZT) and vice versa. Four days after RZT transfer, P max and leaf total soluble sugar content were highest and lowest, respectively, in C-RZT and A-RZT plants. P max and total leaf soluble sugar content were much lower in plants transferred from C-to A-RZT (C→A-RZT) than in C-RZT plants. However, these two parameters were much higher in plants transferred from A-to C-RZT (A→C-RZT) than in A-RZT plants. A-RZT and C→A-RZT plants had higher root total soluble sugar content than A→C-RZT and C-RZT plants. Leaf total insoluble sugar content was similar in leaves of all plants while it was the highest in the roots of C-RZT plants. Developing leaves of C-RZT plants had higher 14C-photoassimilate content than A-RZT plants. The A→C-RZT plants also had higher 14C-photoassimilate content in their developing leaves than A-RZT plants. However, more 14C-photoassimilates were translocated to the roots of A-RZT and C→A-RZT plants, but they were mainly used for root thickening than for its elongation. Increases in leaf area, shoot and root fresh mass were slower in C→A-RZT than in C-RZT plants. Conversely, A→C-RZT plants had higher increases in these parameters than A-RZT plants. Lower root/shoot ratio (R/S) in C-RZT than in A-RZT plants confirmed that more photoassimilates were channelled to the shoots than to the roots of C-RZT plants. Roots of C-RZT plants had greater total length with a greater number of tips and surface area, and smaller average diameter as compared to A-RZT plants. In C→A-RZT plants, there was root thickening but the increases in its length, tip number and surface area decreased. The reverse was observed for A→C-RZT plants. These results further supported the idea that newly fixed photoassimilates contributed more to root thickening than to root elongation in A-RZT and C→A-RZT plants.

A study of 34 cultivars of basil (Ocimum L.) and their morphological, economic and biochemical characteristics, using standardized descriptors.

Abstract: Basil is an important medicinal and aromatic plant that is widely used in many fields. The aim of this study was to evaluate the oil content and ornamental value of a wide range of species and cultivars of Ocimum L. from various different sources, using standardized descriptors. 34 cultivars of basil (Ocimum L.) were grown in two different years at The Faculty of Horticulture in Lednice, Czech Republic. The cultivars were divided into groups according to leaf colour and leaf size. The cultivars displayed a wide diversity of morphological, biological and economic characteristics. The groups of green small-leafed and purple-leafed varieties were judged to be the most decorative. To improve the ornamental value of the Ocimum species the uniformity, colour stability and earliness of flowering should be examined. The essential oil was extracted using hydro-distillation methods. Most of the samples had high essential oil levels (1.8 – 14.3 ml.kg), which were influenced by cultivar, environmental conditions and storage length. The major

Genetic Variability Induced by Gamma Rays and Preliminary Results of Low-Cost TILLING on M2 Generation of Chickpea (Cicer arietinum L.).

Abstract: In order to increase genetic variability for chickpea improvement, the Kabuli genotype, variety Ghab4, was treated with 280 Grays of gamma rays (Cobalt 60). Field characterization began with the M2 generation. A total of 135 M2 families were sown in the field resulting in approximately 4,000 plants. Traits related to phenology (days to flowering, days to maturity), plant morphology of vegetative parts (plant height, height of first pod, number of primary branches per plant) and yield (number of seeds per pod, total number of pods per plant, total number of seeds per plant, seed yield and hundred seed weight) were recorded and analyzed to evaluate genetic variability. An evaluation of the efficacy of low-cost TILLING (Targeting Induced Local Lesions IN Genomes) to discover mutations in the M2 generation was undertaken. Mutation screening focused on genes involved in resistance to two important diseases of chickpea; Ascochyta blight (AB) and Fusarium wilt (FW), as well as genes responsible for early flowering. Analysis of variance showed a highly significant difference among mutant families for all studied traits. The higher estimates of genetic parameters (genotypic and phenotypic coefficient of variation, broad sense heritability and genetic advance) were recorded for number of seeds per plant and yield. Total yield was highly significant and positively correlated with number of pods and seeds per plant. Path analysis revealed that the total number of seeds per plant had the highest positive direct effect followed by hundred seed weight parameter. One cluster from nine exhibited the highest mean values for total number of pods and seeds per plant as well as yield per plant. According to Dunnett's test, 37 M2 families superior to the control were determined for five agronomical traits. Pilot experiments with low-cost TILLING show that the seed stock used for mutagenesis is homogeneous and that small mutations do not predominate at the dosage used.

Transgenic Crop Plants Using Agrobacterium rhizogenes-Mediated Transformation

Abstract: This chapter explores the use of Agrobacterium rhizogenes, which is confined to specific examples with potential applications for plant improvement including: increasing rooting of recalcitrant plants, altering plant phenotype, and the introduction of foreign genes. A. rhizogenes is a soil bacterium responsible for the development of hairy root disease on a range of dicotyledonous plants. A literature survey indicates that transgenic plants have been regenerated from hairy roots of 62 different taxa, representing 53 species from 24 families. In addition, there has been increased interest in the use of A. rhizogenes due to the effect of rol genes on plant morphology and development and the ability to introduce foreign genes via A. rhizogenes-mediated transformation. Progress in A. rhizogenes-mediated transformation of plants from production of hairy roots, to shoot regeneration, to introduction of foreign genes, through to field-testing of transgenic plants, indicates the potential of A. rhizogenes for the production of transgenic crop plants.