To induce new variation within the Escallonia genus, chromosome doubling was performed in E. rubra, E. rosea, and E. illinita, three important species within this genus of mainly evergreen woody ornamental species. Obtained tetraploids and diploid controls were analyzed for rooting capacity, leaf and flower characteristics, and plant architecture using image analysis and cold tolerance. In the ...

Ploidy varies tremendously within and between species, yet the factors that influence when or why ploidy variants are adaptive remains poorly understood. Our previous work found that diploid individuals repeatedly arose within ten replicate haploid populations of Saccharomyces cerevisiae, and in each case we witnessed diploid takeover within ~1800 asexual generations of batch culture evolution ...

Brachypodium distachyon is a model for the temperate cereals and grasses and has a biology, genomics infrastructure and cytogenetic platform fit for purpose. It is a member of a genus with fewer than 20 species, which have different genome sizes, basic chromosome numbers and ploidy levels. The phylogeny and interspecific relationships of this group have not to date been resolved by sequence com...

H A P L O I D vertebrates may occur spontaneously but are very rare (Fankhauser, 1941; Humphrey & Fankhauser, 1957); however, haploids may be experimentally produced in fish (Swarup, 1959) and in mammals (Beatty, 1953), while amphibian eggs may be so treated that all developing embryos are haploid (Porter, 1939; Gurdon, 1960). The full descriptions of the development of haploid Rana pipiens (Po...

PREMISE OF THE STUDY Exotic diseases are threatening many North American tree species, and management of diseases requires understanding the biology of the host as well as the pathogen. Ulmus americana is a widespread dominant tree of eastern North America that has been widely planted as an ornamental and shade tree. Populations of the species have suffered heavy mortality from Dutch elm diseas...

major attributes of mitotic gene conversion in Saccharomyces have been TEai led by ROMAN (1956a) and by KAKAR ( 1961) for heteroallelic diploids, while LINDEGREN (1953) , WINGE (1955) , and PAPAZIAN and LINDEGREN (1960) have investigated instances of aberrant segregation ratios in meiosis. Heteroallelic repair, or gene conversion, is essentially non-reciprocal in character. Three lines of evide...

Abstract The highly variable tufted hairgrass Deschampsia cespitosa is a tussock-forming plant especially of cool and humid environments. Although common widespread, its phylogeographic structure the significance polyploidy for evolution are poorly understood. Here we used phylogenomic approach to study genetic this species in Europe how polyploid cytotypes/subspecies related diploids. Using ge...