This study was conducted to evaluate maternal breed effects, direct breed effects, and individual heterosis on subsequent steer performance, carcass, and feed efficiency traits. This was a consecutive 2-yr trial using 158 steers. The same dam breeds, Angus (AN) and purebred Simmental (SM), were used both years. Also, the same AN and SM sires (n=11) were used both years. Steers were AN, SM, or A...

Heterosis has been widely used in agriculture to increase yield and to broaden adaptability of hybrid varieties and is applied to an increasing number of crop species. We performed a systematic survey of the extent and degree of heterosis for dry biomass in 63 Arabidopsis accessions crossed to three reference lines (Col-0, C24, and Nd). We detected a high heritability (69%) for biomass producti...

Heterosis describes a phenotypic phenomenon of hybrid superiority over its homozygous parents. It is a genetically intriguing phenomenon with great importance for food production. Also called hybrid-vigor, heterosis is created by non-additive effects of genes in a heterozygous hybrid made by crossing two distinct homozygous parents. Few models have been proposed to explain how the combination o...

The genetic basis of heterosis of an elite rice hybrid was investigated by using an "immortalized F(2)" population produced by randomly permutated intermating of 240 recombinant inbred lines from a cross between the parents of Shanyou 63, the most widely cultivated hybrid in China. Measurements of heterosis for crosses in the immortalized F(2) population were obtained from replicated field tria...

OR the reasons that heterosis has immense value in practical utilization in F agriculture and the evolutionary significance of heterosis in natural populations is important, a number of investigators have worked on this problem and proposed numerous hypotheses for the explanation of this phenomenon. The hypotheses which have been proposed can be classified into two categories: (a) dominance the...

quantitative valuations of observed heterosis for 11 traits of 15 f1 hybrids generated by half diallel crosses of six diverse rice cultivars (domsefid, hashemi and binam, three iranian local cultivars; dorfak, kadous and ir30, three improved cultivars), were made in this study. fifteen f1 hybrids and their parents were evaluated in a randomized complete block design with three replications at t...

salinity is one of the abiotic stresses and exploitation of heterosis could increase the crop yield and extend the stress tolerance, especially in salinity stress. in this research, a set of full diallel design involving 7×7 crosses from cultivars including flat, bam, ghods, roshan, arg, kavir and pishtaz were conducted in a randomized complete block design with three replications under both no...

HE heterozygous carriers of some genetic variants are superior in fitness to Tthe corresponding homozygotes. The causation of this hybrid vigor or heterosis (euheterosis according to DOBZHANSKY 1952) constitutes an important but as yet little understood problem. One possibility is that some gene alleles are “overdominant” with respect to fitness, and thus give heterosis in heterozygous conditio...

Identifying the best inbred combinations for the development of commercial hybrid of sunflower remains the main challenge to sunflower breeders. In the present research the level of heterosis of F1 hybrids, genetic diversity of parental lines based on SSR markers, as well as its connection with specific combining ability of sunflower were studied. Ten sunflower elite inbred lines (3 restorer li...

Compared with understanding of biological shape and form, knowledge is sparse regarding what regulates growth and body size of a species. For example, the genetic and physiological causes of heterosis (hybrid vigor) have remained elusive for nearly a century. Here, we investigate gene-expression patterns underlying growth heterosis in the Pacific oyster (Crassostrea gigas) in two partially inbr...