Direct determination of chromosome number in Saccharomyces is advantageous in the further development of yeast genetics. The enumeration of centromeres by deductions from tetrad analysis sets a minimum chromosome number (Lindegren, 1949; Lindegren and Lindegren, 1951b), but interchromosomal linkage (Shult and Lindegren, 1955) introduces complexities into the deduction of chromosomal numbers fro...

In this study, the mutagenic effects of different doses and exposure times oryzalin Nitrogen Protoxide (N2O) were tested for stimulating polyploid on 41 B Fercal grapevine rootstocks seedlings. Ploidy changes examined by morphological, cytological, macroscopic, microscopic methods. Leaf thickness, chlorophyll contents, stomatal sizes, chloroplast numbers seedlings stimulated with mutagens incre...

Chromosome counts and observations of reproduction for 55 taxa of Cactaceae indicate that polyploidy is correlated with self-fertility, adventive embryony, profuse branching, and vegetative reproduction. Six genera (Blossfeldia, Cleistocactus, Frailea, Pelecyphora, Rebutia, and Strombocactus) and 35 species or varieties are reported here for the first time. Preliminary observations of pachytene...