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Soil
Published in Stanley E. Manahan, Environmental Chemistry, 2022
The development of hybrids has vastly increased yields and other desired characteristics of many important crops. Basically, hybrids are the offspring of crosses between two different true-breeding strains. Often quite different from either parent strain, hybrids tend to exhibit “hybrid vigor” and to have significantly higher yields. The most success with hybrid crops has been obtained with corn (maize). Corn is one of the easiest plants to hybridize because of the physical separation of the male flowers, which grow as tassels on top of the corn plant, from female flowers, which are attached to incipient ears on the side of the plant. Despite past successes by more conventional means and some early disappointments with “genetic engineering,” the application of recombinant DNA technology will probably eventually overshadow all the advances ever made in plant breeding.
Core Eudicots: Dicotyledons V
Published in Donald H. Les, Aquatic Dicotyledons of North America, 2017
Systematics: Although Mecardonia and Bacopa have been merged by some authors, analyses of various molecular datasets indicate that the genera are closely related but distinct phylogenetically (Figures 5.82, 5.85, and 5.86). Mecardonia is coherent morphologically and appears to be monophyletic as currently circumscribed (e.g., Figure 5.86); however, a comprehensive phylogenetic survey of the genus has not been conducted and is needed to test this assumption. The base chromosome number of Mecardonia is x = 11. Mecardonia procumbens is diploid (2n = 22); whereas, M. acuminata is tetraploid (2n = 44). Artificially induced tetraploids of M. procumbens have been synthesized and these grow slower, delay flowering, but flower longer than the diploids. A supernumerary (“B”) chromosome has been found in M. procumbens. Several infraspecific taxa have been described for Mecardonia acuminata. The integrity of these taxa has been evaluated by morphological and genetic (ISSR markers) analyses, which fail to uphold the distinctness of M. acuminata var. microphylla, but do indicate the integrity of M. acuminata var. peninsularis. Natural hybrids are not reported in North America, but several hybrid interspecific cultivars have been synthesized, and these appear to retain at least some fertility.
Amplifying User and Producer Innovation
Published in Cornelius Herstatt, Daniel Ehls, Open Source Innovation – The Phenomenon, Participant's Behavior, Business Implications, 2015
Christina Raasch, Eric von Hippel
Different organizational forms can be used to implement innovation amplification, e.g. contests that rely on competition, communities that rely on collaboration, and single-solver forms in which every contributor simply enjoys puzzle solving by and for himself. Hybrids are also possible and in fact common. The relationship between organizational forms and the motives and preferences of the population of potential problem solvers should be explored in more detail (Boudreau and Lakhani 2011; Hill and Monroy-Hernández 2012).
Phytoremediation potential of hybrids of the exotic plant Xanthium strumarium and its native congener Xanthium sibiricum for cadmium-contaminated soils
Published in International Journal of Phytoremediation, 2022
Chenyang Xue, Peidong Tai, Yingmei Gao, Bo Qu
The exotic (alien, non-indigenous, introduced, non-native) species have become a matter of concern in the scientific community (Xue et al. 2021). However, the faster growth rates, greater environmental stress tolerance, and absorption of heavy metals make them ideal candidates for phytoremediation of heavy metals (Michalet et al. 2017; Wei et al. 2018; Frost et al. 2019). Several hybrid plants have been used to extract contaminants from soils. Improved traits in the hybrids, such as faster growth rate and higher biomass, improve their fitness under unfavorable environments (Wan et al. 2015; Li and Xu 2016). For example, Helianthus paradoxs, a transgressive segregant, from the cross H. annuus × H. petiolaris gained salt tolerance traits that enable it to survive in saline-alkaline wetland habitats (Lexer et al. 2003). Similarly, hybrids of Solanum nigrum from two different climate-ecological regions in Sichuan were found to have higher biomass and better Cd extraction efficiency than the parents (Lin et al. 2016). However, few studies have assessed the phytoremediation potential of hybrids of alien species and their native congener species. This study evaluated the phytoremediation potential of hybrids of exotic plant Xanthium strumarium and its native congener X. sibiricum for cadmium-contaminated soils.
The water–man eristic dialectics for sustainable hydro-governance
Published in Water International, 2021
(4) Hybridist model (Figure 5d). The terms ‘hybrid’ and ‘hybridization’ are well known from progress made in natural and zoological sciences producing new plants and animals by genetic manipulation. For example, the famous sheep ‘Dolly’ is reported as the first cloned mammal. Hybrids are also the genetically modified crops (GMO) commercially available in the United States.