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...

333 converted into homozygous parental breeding lines, as desirable allele combinations are lost through recombination during meiosis. That obstacle has been overcome by Wijnker et al. who have reverse bred Arabidopsis thaliana parental lines from heterozygous hybrids using a process that involves preventing meiotic crossing over. The authors used RNA interference (RNAi) to silence DISRUPTED ME...

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...

Doubled haploid plants are invaluable breeding tools but many crop species are recalcitrant to available haploid induction techniques. To test if haploid inducer lines can be engineered into crops, CENH3 (-∕-) and CENH3:RNAi lines were complemented by AcGREEN-tailswap-CENH3 or AcGREEN-CENH3 transgenes. Haploid induction rates were determined following testcrosses to wild-type plants after indep...

On the basis of the first inducer of maternal haploids in maize (Zea mays L.), Stock 6 (Coe, 1959), a number of new inducer lines have been created (Tyrnov et al, 1984; Lasharmes et al, 1988; Sarkar et al, 1994; Shatskaya et al, 1994; Chalyk, 1999; Rober et al, 2005). The inducers possess dominant anthocyanin marker genes allowing haploids to be identified at different stages (dry seeds, seedli...

The major cause of powdery mildew in melons (Cucumis melo L.) is the fungus Sphaerotheca fuliginea. There are several cultivar- and season-specific races of this fungus. In order to control powdery mildew, it is important to introduce resistance to fungal infection into new cultivars during melon breeding. Haploid breeding is a powerful tool for the production of pure lines. In this study, it w...

haploid inducer line can be transferred (DH) technology can not only shorten the breeding process but also increase genetic gain. Haploid induction and subsequent genome doubling are the two main steps required for DH technology. Haploids have been generated through the culture of immature male and female gametophytes, and through inter- and intraspecific via chromosome elimination. Here, we fo...

Abstract This work focuses on the achievements of Polish researchers in field vegetative reproduction plants under vitro conditions. For more than 50 years, micropropagation methods have been used Poland whenever is necessary. Most perennial horticultural crops, such as fruit plants, majority ornamental geophytes, and some vegetables (e.g., rhubarb horseradish), require clonal owing to their hi...

Despite a great deal of theoretical attention, we have limited empirical data about how ploidy influences the rate of adaptation. We evolved isogenic haploid and diploid populations of Saccharomyces cerevisiae for 200 generations in seven different environments. We measured the competitive fitness of all ancestral and evolved lines against a common competitor and find that in all seven environm...