Tagged: Fabaceae




Effects of plant polyploidy on the legume-rhizobia mutualism

Polyploidy alters plant genomes, phenotypes, and abiotic interactions. The effects of polyploidy on plant-biotic interactions however are less well known. One important plant-biotic interaction is the legume-rhizobia mutualism, in which rhizobia fix atmospheric nitrogen in exchange for carbon. Forrester and Ashman propose a framework to understand how polyploidy directly enhances the quantity and quality of rhizobial symbionts hosted by legume plants, resulting in increased host access to fixed nitrogen. They synthesise trends from published studies, reveal gaps in current knowledge, and uncover areas ripe for future research. Although plant polyploidy enhances several key aspects of the mutualism, the underlying mechanisms...

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Vicia cracca

Colchicine application and reproductive fitness in Fabaceae

Unravelling the direct consequences of polyploidization to reveal its evolutionary significance and effects on reproductive fitness, Münzbergová studies diploid offspring of synthetic tetraploid mothers in Vicia cracca (Fabaceae) to assess the effects of colchicine application in the maternal generation. Hitherto there has been a prevailing assumption that the effects of the substances used to create synthetic polyploids disappear in the second generation, with little examination of between population variation in these effects. Seed size and stomata size were primarily affected by cytotype, while plant performance differed between natural and synthetic polyploids. Increased size and fitness of offspring results in the...

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Sand temperature and moisture break seed physical dormancy

Seasonal periodicity of seed germination and its relationship to seasonal changes in temperature and soil moisture have been well studied in seeds of species with physiological dormancy. However, relatively little information is available on the role of these environmental factors in controlling the germination of seeds with physical dormancy. In a new study published in AoB PLANTS, Liu et al. determined whether Eremosparton songoricum (a perennial semi-shrub that inhabits the cold desert and produces seeds that show physical dormancy) exhibits seasonal periodicity of seed germination. They also investigated the relationship between seed dormancy break and soil temperature and moisture. To...

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Lupinus polyphyllus

Demographic consequences of genetic variation for a plant invasion

Genetic variation may play an important role in plant population fitness and invasion success. Li et al. combine genetic analysis and demographic data to investigate the consequences of genetic variation for the population fitness of a perennial, invasive herb (Lupinus polyphyllus). They find that genetic variation correlates positively with the average seedling establishment in the field, but not with the fitness components of later life stages, or the long-term population growth rate (λ). The study suggests that genetic variation may facilitate plant invasions by increasing seedling establishment, but it may not necessarily affect invasion spreading after establishment.

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Molecular analysis and evolution of forisomes

Molecular analysis and evolution of forisomes

Forisomes are specialized structural phloem proteins that mediate sieve element occlusion after wounding exclusively in papilionoid legumes, but most studies of their structure and function have focused on the Old World clade rather than the early lineages. Müller et al. combine sequence analysis and bioinformatics with structural and functional analysis of native forisomes and artificial forisome-like protein bodies, the latter produced by expressing forisome genes from different legumes in a heterologous background. They conclude that forisome structure and function have been strongly conserved during evolution and that species-dependent subsets of SEO-F proteins may have evolved to fine-tune the structure of native...

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Seed quality at tree species’ altitudinal limits

Seed quality at tree species’ altitudinal limits

The low-temperature range limit of tree species may be determined by their ability to produce and disperse viable seeds, with processes such as flowering, pollen tube growth, fertilization, embryogenesis and seed maturation expected to be affected by cold temperatures. Kollas et al. investigate seed quality of nine broadleaved tree species harvested at their upper elevation limits in the Swiss Alps. Measuring morphological, physiological and phenological traits, they find hardly any differences between low- and high-elevation seed sources, and hence populations growing at their low-temperature limit exhibit similar seed quality to populations at lower elevations.

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Floral biomechanics and pollination in Fabaceae

Floral biomechanics and pollination in Fabaceae

Papilionoid Fabaceae include species with flowers that have obstacles that have to be actively moved by a visitor before floral rewards can be accessed and pollination can take place. Córdoba and Cocucci  study six species of Fabaceae and determine the force required to open keels and the strength that pollinating bees (Megachilidae and Apidae) are capable of exerting. They find that almost all bees have more than enough strength to access all flowers with the exception of the relatively weak honey bee Apis melifera. The tripping mechanisms of the flowers therefore do not appear to exert a strong influence in selecting pollinators.

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