in this research, the isolated microspore culture system in 15 rose cultivars was tested. in the first experiment, the effect of rose cultivars on microspore viability and multicellular formation was examined. results showed that the most multicellular structures obtained in ‘apollo’, ‘amarosa’, ‘majic’, ‘candy’, ‘exotic’ and ‘velvet’ varieties. in the second experiment, the effect of various i...

Microspore embryogenesis is a process of cell reprogramming, totipotency acquisition and embryogenesis initiation, induced in vitro by stress treatments and widely used in plant breeding for rapid production of doubled-haploids, but its regulating mechanisms are still largely unknown. Increasing evidence has revealed epigenetic reprogramming during microspore embryogenesis, through DNA methylat...

It is currently accepted that 'stress' triggers induction of microspore embryogenesis, and for Brassica napus L. cv. Topas it is heat-shock. It has been postulated that the heat-shock proteins (HSPs) generated during heat stress have a central role in the induction mechanism. To test this hypothesis we developed a microspore induction procedure, using colchicine instead of heat treatment. The l...

Induction of embryogenesis from isolated microspore cultures is a complex experimental system where microspores undergo dramatic changes in developmental fate. After ~40 years of application of electron microscopy to the study of the ultrastructural changes undergone by the induced microspore, there is still room for new discoveries. In this work, high pressure freezing and freeze substitution ...

Microspore embryogenesis is a method of achieving complete homozygosity from plants. It is particularly useful for woody species, like Citrus, characterized by long juvenility, a high degree of heterozygosity and often self-incompatibility. Anther culture is currently the method of choice for microspore embryogenesis in many crops. However, isolated microspore culture is a better way to investi...

background:  stresses such as heat shock, starvation, or osmotic is essential to lead isolated microspores towards embryogenesis. despite the effectiveness of stresses in embryogenesis, they exert adverse effects on metabolism and growth of the regenerated plants.objectives: the effects of heat shock and 2,4-d treatment on total protein content of treated microspores, morphological and physiolo...

microspore culture was applied to induce embryogenesis in roses (rosa hybrida) cv. hav1. important factors affecting viability of isolated microspores and formation of multi-cellular structures including isolation media (nln, ab, b) and induction media were studied. the most responsive developmental stage of microspores (late unicellular) was determined using dapi staining. the least infection ...

Microspores are reprogrammed by stress in vitro toward embryogenesis. This process is an important tool in breeding to obtain double-haploid plants. DNA methylation is a major epigenetic modification that changes in differentiation and proliferation. We have shown changes in global DNA methylation during microspore reprogramming. 5-Azacytidine (AzaC) cannot be methylated and leads to DNA hypome...

The induction of microspore embryogenesis produces dramatic changes in different aspects of the cell physiology and structure. Changes at the cell wall level are among the most intriguing and poorly understood. In this work, we used high pressure freezing and freeze substitution, immunolocalization, confocal, and electron microscopy to analyze the structure and composition of the first cell wal...