Efficient Androgenic Embryo Induction and Plant Regeneration in Different Genotypes of Sweet Pepper via Anther Culture

Creation of pure lines is one of the basic requirements in plant breeding. Doubled haploid (DH) lines are completely homozygous lines and anther culture is an efficient method for DH line production. Induction of androgenic embryos in anther culture is the main restricting factor. In this study we investigated androgenic embryo induction in different F1 hybrid peppers including Cadia, Magno, Plato, King Arthur and Maratus. Excised anthers were cultured in C medium containing 2 mg L-1 2-4D and 2 mg L-1 Kinetin and incubated at 35°C for eight days and followed by four days at 25°C in darkness, then anthers sub cultured to R medium containing 0.1 mg L-1 Kinetin and incubated at 25°C and 16h photoperiod. The effect of genotype, cold pretreatment (4°C, 24 h) and heat shock on the efficiency of anther culture in pepper (Capsicum annuum L.) was evaluated. Cold pretreatment applied to excised buds improved microspore embryogenesis efficiency as compared to control. Among genotypes tested, Cadia, Magno, and Maratus were shown to be more responsive than King Arthur and Plato. Plants produced in responsive genotypes were approximately three-fold higher (2.5, 2.33 and 2.33 regenerated plant per petri dish, respectively) than King Arthur and Plato (0.83 and 0.66, respectively). Results showed that heat shock (35°C) applied to cultured anthers was effective on microspore embryogenesis, as heat shock (35°C) treatment for eight days had the best results in Cadia with 0.16 plant per petri dish

Pseudo-embryogenic Structures in Anther and Isolated Microspore Cultures in vitro: a Cautionary Guide

This review describes sources of structures of non-microspore origin observed in anther and microspore cultures. Various characteristics of these structures may cause a wrong diagnosis of these structures as embryos or cell/tissue clusters of microspore origin. Here we suggest such structures to be named as pseudo-embryogenic structures. The introduction of pseudo-embryogenic structures and their origins could be helpful to distinguish them from true microspore-derived structures. Prompted by certain environmental cues, somatic cells existing as a contamination in immature pollen (microspores) cultures can lead to the formation of 'pseudo-embryos' commonly known as embryoids. The pseudo-embryogenic structures may be classified in the following groups: (i) pseudo-star-like structures; pseudo-multicellular structures; (ii) pseudo-embryos with pseudo-suspensors; (iii) contaminating bacteria appearing as callus colonies; (iv) calli and embryos of somatic origin; (v) giant tetrad-like structures; (vi) anther wall cells. The exact origin of these structures is discussed in this paper, and some recommendations are proposed in order to avoid misinterpretation.EUEuropean Commission [COOP-CT-2003-508210]A part of the results presented here was supported by the EU funded project HAPLOTECH COOP-CT-2003-508210

Pseudo-embryogenic structures in anther and isolated microspore cultures in vitro: a cautionary guide

This review describes sources of structures of non-microspore origin observed in anther and microspore cultures. Various characteristics of these structures may cause a wrong diagnosis of these structures as embryos or cell/tissue clusters of microspore origin. Here we suggest such structures to be named as pseudo-embryogenic structures. The introduction of pseudo-embryogenic structures and their origins could be helpful to distinguish them from true microspore-derived structures. Prompted by certain environmental cues, somatic cells existing as a contamination in immature pollen (microspores) cultures can lead to the formation of 'pseudo-embryos' commonly known as embryoids. The pseudo-embryogenic structures may be classified in the following groups: (i) pseudo-star-like structures; pseudo-multicellular structures; (ii) pseudo-embryos with pseudo-suspensors; (iii) contaminating bacteria appearing as callus colonies; (iv) calli and embryos of somatic origin; (v) giant tetrad-like structures; (vi) anther wall cells. The exact origin of these structures is discussed in this paper, and some recommendations are proposed in order to avoid misinterpretation.EUEuropean Commission [COOP-CT-2003-508210]A part of the results presented here was supported by the EU funded project HAPLOTECH COOP-CT-2003-508210