Managing Seed Dormancy in Forage Legumes and Grasses: An Update

Seed dormancy is a common feature of the majority of forage species. It usually causes problems both to the grower and the seed analyst. Many methods have been developed to break dormant seed over the time, and efficacy of a method usually varies with species and cultivars. The objective of this paper is to review and summarise important methods used for seed dormancy breaking in forage legume and grass species, and the mechanisms involved

Does Scarification Time Affect Hydrotime Model Parameters of \u3cem\u3eVicia angustifolia\u3c/em\u3e Seed Germination?

Hard seed, also classified as physical dormancy, is very common in forage legumes (Baskin and Baskin 2004). Many methods, based on scarifying seed coat have been developed such as mechanical scarification, chemical scarification to soft hard seed (Baskin and Baskin 1998). Hydrotime is a way to describe the relationship between water potential (Ψ) and seed germination rates and percentages (Bradford 1990) The hydrotime model has proven to be useful for understanding the physiological mechanism of seed germination and has been suggested as a tool to describe seed germination time in relation to water condition (Alvarado and Bradford 2002). Generally, the effect of water condition on legume seed germination was evaluated on seeds after dormancy was broken. However, the way various treatments affecting seed response to water potential and the ecological significance of the response is less well understood (Zuk-gołaszewska et al. 2007). This study aimed to test the effect of sulfuric acid scarification on hydrotime model parameters of Vicia angustifolia

Combinational Dormancy of \u3cem\u3eVicia angustifolia\u3c/em\u3e Seed and Its Ecological Significance

Combinational dormancy is a common phenomenon in seed of temperate legume species, however, less is known about its ecological role in an alpine environment (Hu et al. 2013). Vicia angustifolia is an annual herbaceous legume, widely distributed in the Qinghai-Tibet Plateau. The purpose of this study is to explore the seed dormancy characteristics of V. angustifolia and its ecological significance

Effects of Litter on Seedling Emergence and Seed Persistence of Three Common Species on the Loess Plateau in Northwestern China

Litter accumulation resulting from land use change (enclosure) is one of the key variables influencing seedling recruitment and consequently the regeneration of plant populations and seed persistence in the soil seed bank. A better understanding of the effects of litter on seed germination and seedling emergence is crucial for developing a new set of indicators for grassland ecosystem health and for grassland management policy. We investigated the effects of seed position in litter and amount of litter covering the seed on seedling emergence and seed persistence of three common species on the Loess Plateau in northwestern China. Seed position beneath the litter layer provided a suitable environment for seedling emergence of the three species. A moderate amount of litter (160 g/m2) was beneficial for seedling emergence of the small-seeded species Stipa bungeana and Lespedeza davurica from seeds from beneath the litter layer. The large-seeded species Setaria glauca was more tolerant of a high amount of litter (240 g/m2) than the two small-seeded species. Seed persistence in the soil differed among the three species and also was affected by seed position in litter and amount of litter cover. The proportion of viable seeds of Stipa bungeana and Setaria glauca on top of the litter layer increased with an increase in amount of litter. Seedling emergence and seed persistence varied significantly among species, amount of litter and seed position in litter. A moderate amount of litter and seeds positioned beneath the litter layer were better for seedling recruitment than for those on top of the litter layer. A high amount of litter was more favorable for persistence of seeds positioned on top of the litter than for those beneath the litter. Our study showed that maintaining litter amount between 80 and 160 g/m2 is optimal for S. bungeana dominated grassland on the Loess Plateau. We suggest that litter amount can serve as a guide for monitoring and managing grassland ecosystems, as it is an indicator of ecosystem processes that are essential for biodiversity conservation and restoration

Learning-based deformable image registration for infant MR images in the first year of life

Many brain development studies have been devoted to investigate dynamic structural and functional changes in the first year of life. To quantitatively measure brain development in such a dynamic period, accurate image registration for different infant subjects with possible large age gap is of high demand. Although many state-of-the-art image registration methods have been proposed for young and elderly brain images, very few registration methods work for infant brain images acquired in the first year of life, because of (1) large anatomical changes due to fast brain development and (2) dynamic appearance changes due to white matter myelination

Comparison of Thermal and Hydrotime Requirements for Seed Germination of Seven \u3cem\u3eStipa\u3c/em\u3e Species from Cool and Warm Habitats

Temperature and water potential are two important environmental factors influencing germination and subsequent seedling establishment. Seed germination requirements vary with species and with the environment in which the seeds are produced. Stipa species dominate large areas of the Eurasian zonal vegetation, but comparisons of germination requirements between Stipa species from different habitats is limited. We investigated the effects of temperature and water potential on seed germination of S. grandis, S. purpurea, and S. penicillata from habitats with low temperatures and relatively abundant rainfall (cool habitats) and S. glareosa, S. breviflora, S. gobiea, and S. bungeana from habitats with relatively high temperatures and low amount of rainfall (warm habitats). Seeds of species from cool habitats had a higher base (Tb), optimal (To), and maximum (Tc) temperature than those of species from warm habitats, except for the base temperature of S. purpurea. Response of six tested Stipa species to water potential differed among species but not between habitats. Median water potential for germination was lowest for S. bungeana, S. penicillata, and S. gobiea. There was a negative correlation between hydrotime constant (θH) and base water potential for 50% of the seeds of all species to germinate (ψb(50)). Germination time of seven Stipa species in response to temperature and water was well predicted by thermal time and hydrotime models. Results of the present study on germination of these seven species of Stipa may provide useful suggestions for grassland restoration in different habitats