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sporophytes have been discovered in many plant species; STADLER and RANDOLPH first reported haploidy in maize (1929 unpublished, cited by RANDOLPH 1932).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...

Citrus is a highly valued tree crop worldwide, while, at the same time, citrus production faces many biotic challenges, including bacterial canker and Huanglongbing (HLB). Breeding for disease-resistant varieties is the most efficient and sustainable approach to control plant diseases. Traditional breeding of citrus varieties is challenging due to multiple limitations, including polyploidy, pol...

The genus Cyrtopodium comprises about 42 species distributed from southern Florida to northern Argentina. Cyrtopodium polyphyllum occurs on rocks or in sandy soils, in restinga vegetation along the Brazilian coast. It flowers during the wet season and its inflorescences produce a high number of resupinate yellow flowers. Cyrtopodium polyphyllum offers no rewards to its pollinators, but mimics t...

The causes of temporal variation in the twinning rate are not always clear. As a consequence, the study of this variation has attracted the attention of several authors who were also interested in the correlation between twinning rate and human fertility. Prematurity, low birth weight, increased risk of infant death and long-term risk for morbidity associated with multiple gestations have been ...