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 physiol...

True-breeding lines are required for the development and production of crop varieties. In a classical breeding approach these lines are obtained through inbreeding, and often 7-9 generations of inbreeding is performed to achieve the desired level of homozygosity, over a period of several years. In contrast, the chromosomes of haploids can be doubled to produce true-breeding lines in a single ge...

The production of maize doubled haploid (DH) lines is a technique commonly used by private companies, but not by Brazilian public institutions. Research on this technique is essential to develop and improve the production of DH lines grown under tropical conditions. We assessed the ability of a gynogenetic haploid inducer system to induce haploids in a tropical environment, assessed the inducti...

Sexual reproduction of plants starts with the formation of gametes and a 2-fold reduction in the number of chromosomes (ploidy) of these cells. Fertilization, the union of sperm and egg cell restores the ploidy level to its normal value again. During the formation of pollen grains, the structures that contain the male gametes, the reduction in the number of chromosomes happens when the vegetati...

Doubled haploids are routinely created and phenotypically selected in plant breeding programs to accelerate the breeding cycle. Genomic selection, which makes use of both phenotypes and genotypes, has been shown to further improve genetic gain through prediction of performance before or without phenotypic characterization of novel germplasm. Additional opportunities exist to combine genomic pre...