[A Complex Morpho-Histological Approach to the In Vitro Study of Morphogenic Structures in a Wheat Anther Culture].

The external morphological and internal histological features of morphogenic structures (embryoids, calli with embryoids, and calli with buds and roots) have been studied in vitro in a wheat anther culture by light microscopy. The results of this study have been compared with data obtained earlier by scanning electron microscopy.

[Phenomenon of "Siamese Embryos" in Cereals in vivo and in vitro: Cleavage Polyembryony and Fasciations].

The genesis of wheat microsporial polyembryoids in vitro was analyzed in detail. The nature of different phenotypes of cereal polymeric embryos was identified. They represent the class "multiple shoot meristems," which results from a cleavage polyembryony and is accompanied by organ fasciations of all known types (radial, flat, or ring). The morphological nature of cereal embryonic organs has been clarified: shoot meristem­axial organ; scutellum­lateral outgrowth of this axis; coleoptile­derivative of shoot meristem but fused with scutellum; terminality of scutellum­the result of linear fasciation that occurred historically. An explanation is given on how the structural model of an auxin polar transport works during the establishment of bilateral symmetry in a cereal embryo that is associated with the inverted polarization of the carrier protein PIN1 on cell membranes and, correspondingly, with the inverted auxin transport performed by this carrier (Fischer-Iglesias et al., 2001; Forestan et al., 2010).

[Properties of the initial stages of embryoidogenesis in vitro in wheat calli of various origin ].

The formation of embryoids obtained in vitro both in the culture of anthers and in the culture of the germs of spring soft wheat was analyzed using light microscopy and electron microscopy. The features ofembryoid for- mation in the calli of both types are detected.

[Wheat androgenic embryoids and calli: data of scanning electron microscopy]. / Androgennye émbrioidy i kallusy pshenitsy: dannye skaniruiushchei élektronnoi mikroskopii.

The surface of wheat androgenic embryoids and calli at different developmental stages was studied using SEM. The embryoids were already characterized by regular cell divisions at the early developmental stages, while the calli were represented by irregular cell conglomerates. This trend was preserved during further development of androgenic structures. SEM studies of the surface of so-called secondary embryoids confirmed these observations.

[Induction of androgenesis in vitro in the spring soft wheat. Balance of exogenous and endogenous phytohormones]. / Induktsiia androgeneza in vitro u iarovoi miagkoi pshenitsy. Balans ékzogennykh i éndogennykh fitogormonov.

We analyzed the phytohormonal features of the induction of androgenesis in vitro in cultured spring soft wheat anthers. It is stressed that switching the program of microspore development from the gametophytic to the sporophytic pathway is controlled by the balance of exogenous and endogenous phytohormones.