Genomes of Meniocus linifolius and Tetracme quadricornis reveal the ancestral karyotype and genomic features of core Brassicaceae.

Brassicaceae represents an important plant family from both a scientific and economic perspective. However, genomic features related to the early diversification of this family have not been fully characterized, especially upon the uplift of the Tibetan Plateau, which was followed by increasing aridity in the Asian interior, intensifying monsoons in Eastern Asia, and significantly fluctuating daily temperatures. Here, we reveal the genomic architecture that accompanied early Brassicaceae diversification by analyzing two high-quality chromosome-level genomes for Meniocus linifolius (Arabodae; clade D) and Tetracme quadricornis (Hesperodae; clade E), together with genomes representing all major Brassicaceae clades and the basal Aethionemeae.

Stamen curvature and temporal flower closure assure reproductive success in an early-spring-flowering perennial in the cold desert of Middle Asia.

Floral organ movements that ensure autonomous selfing are likely to occur in species that grow in habitats with pollinator scarcity and/or an unpredictable environment. Stamen curvature and temporal flower closure are two important floral behaviors that can influence plant pollination mode and reproductive success. However, both behaviors are rarely reported within a species, and little is known about how these two movements of floral organs ensure reproductive success in an unpredictable early spring environment with few pollinators.

Flexibility of resource allocation in a hermaphroditic-gynomonoecious herb through deployment of female and male resources in perfect flowers.

Premise Of The Study: It has been hypothesized that two flower types permit flexible allocation of resources to female and male functions, yet empirical evidence for the sex-allocation hypothesis remains scarce in gynomonoecious species. To characterize resource allocation to pistillate and perfect flowers and allocation of perfect flowers between gynomonoecious and hermaphroditic individuals, we examined the flexibility and whether female-biased allocation increases with plant size in the hermaphroditic-gynomonoecious herb .

Methods: Frequency of gynomonoecious individuals, flower production, and plant size were investigated in different populations.

Resolution of Brassicaceae Phylogeny Using Nuclear Genes Uncovers Nested Radiations and Supports Convergent Morphological Evolution.

Brassicaceae is one of the most diverse and economically valuable angiosperm families with widely cultivated vegetable crops and scientifically important model plants, such as Arabidopsis thaliana. The evolutionary history, ecological, morphological, and genetic diversity, and abundant resources and knowledge of Brassicaceae make it an excellent model family for evolutionary studies. Recent phylogenetic analyses of the family revealed three major lineages (I, II, and III), but relationships among and within these lineages remain largely unclear.

Intermediate complex morphophysiological dormancy in seeds of the cold desert sand dune geophyte Eremurus anisopterus (Xanthorrhoeaceae; Liliaceae s.l.).

Background And Aims: Little is known about morphological (MD) or morphophysiological (MPD) dormancy in cold desert species and in particular those in Liliaceae sensu lato, an important floristic element in the cold deserts of Central Asia with underdeveloped embyos. The primary aim of this study was to determine if seeds of the cold desert liliaceous perennial ephemeral Eremurus anisopterus has MD or MPD, and, if it is MPD, then at what level.

Methods: Embryo growth and germination was monitored in seeds subjected to natural and simulated natural temperature regimes and the effects of after-ripening and GA3 on dormancy break were tested.

Pistillate flowers experience more pollen limitation and less geitonogamy than perfect flowers in a gynomonoecious herb.

Gynomonoecy, a sexual system in which plants have both pistillate (female) flowers and perfect (hermaphroditic) flowers, occurs in at least 15 families, but the differential reproductive strategies of the two flower morphs within one individual remain unclear. Racemes of Eremurus anisopterus (Xanthorrhoeaceae) have basal pistillate and distal perfect flowers. To compare sex allocation and reproductive success between the two flower morphs, we measured floral traits, pollinator preferences, and pollen movement in the field.

Effect of seed position in spikelet on life history of Eremopyrum distans (Poaceae) from the cold desert of north-west China.

Background And Aims: Most studies on seed position-dependent effects have focused on germination characteristics. Our aim was to determine the effects of seed position in the spikelet on differences in timing of germination and on the ecological life history of the grass Eremopyrum distans in its cold desert habitat.

Methods: For seeds in three spikelet positions, morphology, mass and dormancy/germination characteristics were determined in the laboratory, and seeds planted in field plots with and without watering were followed to reproduction to investigate seedling emergence and survival, plant size and seed production.

An examination of the function of male flowers in an andromonoecious shrub Capparis spinosa.

The pollen donor and pollinator attractor hypotheses are explanations for the functions of the male flowers of andromonoecious plants. We tested these two hypotheses in the andromonoecious shrub Capparis spinosa L. (Capparaceae) and confirmed that pollen production and cumulative volume and sugar concentration of nectar do not differ between male and perfect flowers.