Male sterility is defined as the failure of plants to produce functional anthers, pollen, or male gametes. First documentation of male sterility came in 1763 when Kölreuter observed anther abortion within species and specific hybrids. It is more prevalent than female sterility, probably because, male sporophyte and gametophyte less protected from environment than ovule and embryo sac. Male ster...

Three or four percent of the wild flies in natural populations of D. melanogaster have been found to be sterile. An analysis of sterility associated with the second chromosome revealed a much lower frequency of genetically sterile flies. The accumulation of sterility genes in a cage population was proportional to that of lethal genes, as were their equilibrium frequencies in several natural pop...

Recent genetic analyses of closely related species of Drosophila have indicated that hybrid male sterility is the consequence of highly complex synergistic effects among multiple genes, both conspecific and heterospecific. On the contrary, much evidence suggests the presence of major genes causing hybrid female sterility and inviability in the less-related species, D. melanogaster and D. simula...

apricot (prunus armeniaca), palys an important role in fruit production industry in iran. irregular set of fruit, caused by either sterility of flower organs or incompatibility has been the main problem in apricot production over the years. in this study, it has been attempted to determine these phenomena for four apricot cvs. namely ‘shahroodi’, ‘nasiri’, ‘jahangiri’ and ‘noori’ through the me...

Partial or complete sterility is of frequent occurrence in species crosses. Within the same genus certain species are sterile when crossed while ather combinations are completely fertile. Partial sterility may cause the elimination of certain classes of gametes and prevent desired recombinations of characters in the second generation. Sterility may also cause an abnormal vegetative development....

There are female and male sterility. The female sterility can be particularly divided into absolute, primary and secondary one. The absolute sterility is present if the female genitals have no uterus or ovaries and if there are other bad female genitals development anomalies incompatible with becoming pregnant. The «primary sterility » diagnosis can be made if the woman was pregnant never befor...

For normal sexual reproductive development, coordination must occur between both male and female organ ontogeny. An abnormality at any point in this process may lead to sterility. Classification of sterility can be divided into heritable and nonheritable sterility. Numerous schemes for mechanisms controlled by nuclear genes (genic male sterility) have been devised to identify the timing and loc...