Stenospermy and seed development in the “Brazilian seedless” variety of sugar apple (Annona squamosa)

Abstract

Stenospermy was identified in naturally occurring sugar-apple (Annona squamosa) mutants with great potential for use in genetic improvement programs. However, to date, there have been no detailed studies of the development of aspermic fruit in this species. The aim of the present study was to characterize the anatomy of developing fruit in the 'Brazilian Seedless' mutant. Flower buds in pre-anthesis and developing fruits were subjected to common plant anatomy techniques. The abnormal ovules are unitegmic and orthotropic and have a long funiculus. There is evidence of fertilization, including the presence of embryos in early development and the proliferation of starch grains in the embryo sac. However, the embryos and embryo sac degenerate, although this does not affect pericarp development. Ovule abortion does not occur. The perisperm, which is formed from the peripheral layers of the nucellus, fills the cavity left by the embryo sac. The mature fruit contains numerous small sterile seeds with abundant perisperm and unlignified integument that is restricted to the micropylar region. The majority of perisperm cells are living and appear to be metabolically active in the periphery. Therefore, stenospermy leads to the formation of sterile seeds in A. squamosa, and the perisperm possibly play an important role in fruit development.

Inheritance of seedlessness and the molecular characterization of the INO gene in Annonaceae

“…These preliminary data suggest a monogenic inheritance with complete dominance-type allelic interaction. The seedlessness of the Annona Brazilian seedless variety was due to the formation of a stenospermal fruit with partially formed seeds due to their abortion after fertilization, as reported for Vitis vinifera and Annona squamosa (Bouquet and Danglot, 1996;Lora et al, 2011;Mendes et al, 2012;Santos et al, 2014). A monogenic inheritance with complete cultivar, originated from a natural mutation, is the only seedless A. squamosa cultivar developed in Brazil, but it has an irregular shape and low yield and commercial value (Pereira et al, 2014).…”

“…The stenospermy in this mutant is due to the suppression of the INO gene, leading to a loss of the outer integument of the ovule, which affects seed development (Lora et al, 2011). The first reports regarding the aspermic condition of the 'Brazilian seedless' variety appeared starting from 2014, together with the stenospermy type, which may be related to the suppression of the INO gene (Santos et al, 2014).…”

Propagation of Annonaceous plants

“…Pollination is followed by coupling, copulation, zygote formation and seed development, which can be divided into three phases, the first characterized by cell divisions, histodifferentiation and morphogenesis of the basic plane of the embryo, as well as high water content ( BEWLEY et al, 2013). In A. squamosa, the early development of the embryo and endosperm occur after 24h of pollination (SANTOS et al, 2014). In Annona emarginata, high cell division was observed, but the embryo was not yet differentiated at 49 days after flowering (DAF), at 91 DAF, the embryo already had differentiated axes and cotyledons and germination capacity (CORSATO, 2014).…”

Pavilion BIO-FADEN 1.0: Experimental study of design and manufacture with digital technologies of bionic prototype inspired by the fruit peels of fruit species present in the Central-Western Region of Brazil

“…The main objective of this experiment was to determine the possibilities and limitations of the design, digital fabrication by section or 2D laser cut and the production of artifacts composed of double curvature faces. The artifacts were inspired by the non-Euclidean geometric shapes of the fruits of atemoia -Annona Cherimola, Mill and Annona Squamosa, L. , Cruz et al 2013, buriti or Mauritia Flexuosa (Reis et al, 2017;Silva et al, 2014), soursop or Annona Muricata (Sacramento et al, 2003) and, the Pine cone or Count's fruit or Annona Squamosa (Santos, 2014).…”