Isolated microspore culture in vitro (IMC) is an advanced technique for producing doubled haploids. We developed a modified isolation method the Brassicaceae family, which exceeds results obtained by standard method. found that new allows increase percentage of microspores at embryogenic stage development culture. In spring rapeseed ‘Ratnik’ increases from 66.7% to 73%, and European radish ‘RBK...

In the textbook view, the ratio of X chromosomes to autosome sets, X:A, is the primary signal specifying sexual fate in Drosophila. An alternative idea is that X chromosome number signals sex through the direct actions of several X-encoded signal element (XSE) proteins. In this alternative, the influence of autosome dose on X chromosome counting is largely indirect. Haploids (1X;1A), which poss...

Saccharomyces cerevisiae Gpi3p is the UDP-GlcNAc-binding and presumed catalytic subunit of the enzyme that forms GlcNAc-phosphatidylinositol in glycosylphosphatidylinositol biosynthesis. It is an essential protein with an EX7E motif that is conserved in four families of retaining glycosyltransferases. All Gpi3ps contain a cysteine residue four residues C-terminal to EX7E. To test their importan...

irst case of haploidy in higher plants was reported in Datura stramonium T $ : ~ ~ ~ ~ ~ ~ ~ et al. 1922). Subsequently, haploid sporophytes have been discovered in many plant species; STADLER and RANDOLPH first reported haploidy in maize (1929 unpublished, cited by RANDOLPH 1932). Numerous investigations have been conducted on the occurrence of spontaneous and induced haploids in a number of s...

The coordination of cell growth and division has been examined in isoaenic hanloid and dioioid strains of Saccharomyccs cerevisiae. The average cell volume of the haploid and diploid ‘cells was unaffected by a range of environmental conditions and generation times. For most environments and generation times the mean cell volume of diploid cells was between 1.52 and 1.83 of the haploid cell volu...

Drought stress is one of the major environmental constraints to crop plants including wheat worldwide. Synthetic hexaploid can act as a vehicle for improving crop tolerance against biotic and abiotic stresses. Doubled haploid population consisting of one hundred and forty individuals derived from cross of Opata and SH223 was used in the present study to identify genomic regions associated with ...

Synapsis and chiasma formation have been analyzed at the ultrastructural level in trihaploid wheat with and without chromosome 5B by spreading of microsporocytes. The euhaploids were obtained by anther culture of euhexaploid or monosomic 5B Chinese Spring wheat or from the hexaploid Chinese winter wheat variety Kedong. All three types of euhaploid wheat were virtually achiasmatic. Analysis of 3...

Many years ago Hertwig (1) and Dalcq (2) showed that trypaflavine has the property of inactivating the frog sperm nucleus without affecting the extranuclear parts of the cell. Following an appropriate treatment with the dye, the sperm cells still retain their capacity to activate eggs, but contribute no chromosomes to the resulting embryos, which then develop as haploids with the maternal chrom...

Haploids and doubled haploid (DH) inbred lines have become an invaluable tool for maize genetic research and hybrid breeding, but the genetic basis of in vivo induction of maternal haploids is still unknown. This is the first study reporting comparative quantitative trait locus (QTL) analyses of this trait in maize. We determined haploid induction rates (HIR) in testcrosses of a total of 1061 p...