Foliar application of micronutrient is a rapid and promising strategy to enhance the concentration and bioavailability of micronutrients in wheat grain. To explore the effects of foliar application of micronutrients on the concentration and bioavailability of zinc and iron in grain in wheat cultivars and landraces, field experiments were carried out using 65 wheat cultivars and 28 landraces to assess the effects of foliar application of zinc (iron) on phytic acid concentrations, zinc (iron) concentrations and their molar ratios. The results indicated that mean grain zinc concentration of landraces (44.83 mg kg−1) was 11.13% greater than that of cultivars (40.34 mg kg−1) on average across seasons, while grain iron concentration did not differ significantly between landraces (41.00 mg kg−1) and cultivars (39.43 mg kg−1). Foliar zinc application significantly improved the concentration and bioavailability of zinc in grains in both cultivars and landraces, while landraces had almost two-fold more increase in grain zinc and also greater improvement in zinc bioavailability compared to cultivars. While foliar iron application did not significantly affect iron concentration and bioavailability in grains in either cultivars or landraces. Our study showed that, with foliar application of zinc but not iron, wheat landraces had better performance than cultivars in terms of the increases in both concentration and bioavailability of micronutrient in grains.
Using light and scanning electron microscopy, we studied the pollen morphology of six species (one of which are endemic) of Chinese Pseudostellaria. All species were studied for the first time. Results of this study indicated that pollen grains of Pseudostellaria are spheroidal or spheroidal-polyhedral in shape and small or medium in size and pantoporate. Each pollen grain has 12-16 round pores. These pores are apart from each other by 5.77-7.73 μm and each has 7-13 granules in the operculum region. These features have important taxonomic significance. In addition, their pollen grains have thin exine with microechinate-punctate-perforate surface ornamentation. Pollen features do not support the traditional infrageneric classification of Pseudostellaria into two sections, but support that Pseudostellaria is closely related to other species of the Odontostemma clade. K E Y W O R D S palynological, pollen morphology, Pseudostellaria, systematics
The stigma morphology can provide a reference for exploring plant systematics and pollination biology. In this study, we observed the stigma morphological characteristics of Rosaceae in Beijing urban area in detail using light microscopy and scanning electron microscopy. The stigma of Rosaceae is entire or bilobed and mostly baculate, crateriform, cristate, discoid, or flattened. The stigma surface may have irregular, strongly raised ridges; or flat without papillae; or composed of densely or loosely arranged papillary cells. Surface ornamentation includes fossulate, psilate, psilate-striate, rugulate, scabrate, striate, and striate-rugulate. There are similarities in stigma morphology among genera and differences in stigma morphology among species within genera. The stigma shape supports the view of molecular systematic classification, that is, the former subfamilies Maloideae, Prunoideae, and Spiraeoideae are grouped into subfamily Amygdaloideae.
Research Highlights• Scanning electron microscopy (SEM) was used to provide high-quality figures for observing stigma morphology.• The data on the morphological diversity of stigma were provided to further explore the systematics and pollination biology of Rosaceae.
The systematic position of Veratrum has been controversial for many years. The purpose of the present research is to study embryological features and the systematic position of Veratrum in detail. Microsporogenesis, megasporogenesis, development of male and female gametophyte and changes of anther wall structure during pollen development of V. grandiflorum and V. nigrum were studied using conventional paraffin sectioning technique and light microscopy for the first time, and pollen morphology of V. grandiflorum with scanning electron microscopy was investigated. The results showed that 1) cytokinesis of both V. grandiflorum and V. nigrum microsporocytes is of the successive type; 2) microspore tetrads are either tetragonal or tetrahedral; 3) mature pollen grains are two-celled with wide-elliptic morphology, round ends at the polar view, a monosulcate colpus and reticulate surface ornamentation; 4) ovaries have axile placenta with three locules, each of which has multiple campylotropous, bitegmic, crassinucellate ovules with micropyle formed by the inner integument; and 5) their female gametophyte is of the Allium-type. Overall, these results support classification of Veratrum in Melanthiaceae (Liliales).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.