| confocal microscopy of whole ovules for analysis of reproductive development: the elongate1 mutant affects meiosis ii. | analysis of female meiosis (megasporogenesis) and embryo sac development (megagametogenesis) in angiosperms is technically challenging because the cells are enclosed within the nucellus and ovule tissues of the female flower. this is in contrast to male sporogenesis and gametogenesis where development can readily be observed through the easily dissectable developing anthers. observation of embryo sac development is a particular problem in crassinucellate ovules such as those of maize. to overcom ... | 2005 | 15998316 |
| expressivity of apomixis in 2n + n hybrids from an apomictic and a sexual parent: insights into variation detected in pilosella (asteraceae: lactuceae). | reproductive variation was studied in the tetraploid pilosella aurantiaca, hexaploid p. rubra (both species with facultative autonomous apospory) and in their 2n + n hybrids, which were obtained by crossing with a sexual pollen parent (tetraploid p. officinarum). the different dna content in p. aurantiaca and p. officinarum demonstrated the actual 2n + n origin, both spontaneous from the field and through experimental crosses, of their hexaploid hybrids. the octoploid 2n + n progeny were recover ... | 2011 | 20978805 |
| estimating detection-effort curves for plants using search experiments. | recent studies suggest that plant detection is not perfect, even for large, highly visible plants. however, this is often not taken into account during plant surveys where failing to detect a plant when present can result in poor management and biodiversity outcomes. including knowledge of imperfect detectability into survey design and evaluation is hampered by the paucity of empirical data, and in particular, how detectability will change with search effort, plant size and abundance, the surrou ... | 2011 | 21563589 |
| chromosomes carrying meiotic avoidance loci in three apomictic eudicot hieracium subgenus pilosella species share structural features with two monocot apomicts. | the loss of apomeiosis (loa) locus is one of two dominant loci known to control apomixis in the eudicot hieracium praealtum. loa stimulates the differentiation of somatic aposporous initial cells after the initiation of meiosis in ovules. aposporous initial cells undergo nuclear proliferation close to sexual megaspores, forming unreduced aposporous embryo sacs, and the sexual program ceases. loa-linked genetic markers were used to isolate 1.2 mb of loa-associated dnas from h. praealtum. physical ... | 2011 | 21896890 |
| the new flora of northeastern usa: quantifying introduced plant species occupancy in forest ecosystems. | introduced plant species have significant negative impacts in many ecosystems and are found in many forests around the world. some factors linked to the distribution of introduced species include fragmentation and disturbance, native species richness, and climatic and physical conditions of the landscape. however, there are few data sources that enable the assessment of introduced species occupancy in native plant communities over broad regions. vegetation data from 1,302 forest inventory plots ... | 2013 | 22961328 |
| wild plant species growing closely connected in a subalpine meadow host distinct root-associated bacterial communities. | plant roots are known to harbor large and diverse communities of bacteria. it has been suggested that plant identity can structure these root-associated communities, but few studies have specifically assessed how the composition of root microbiota varies within and between plant species growing under natural conditions. we assessed the community composition of endophytic and epiphytic bacteria through high throughput sequencing using 16s rdna derived from root tissues collected from a population ... | 2015 | 25755932 |
| a dispersal-constrained habitat suitability model for predicting invasion of alpine vegetation. | developing tools to predict the location of new biological invasions is essential if exotic species are to be controlled before they become widespread. currently, alpine areas in australia are largely free of exotic plant species but face increasing pressure from invasive species due to global warming and intensified human use. to predict the potential spread of highly invasive orange hawkweed (hieracium aurantiacum) from existing founder populations on the bogong high plains in southern austral ... | 2008 | 18488601 |