Cotton is one of the most important commercial crops in India, playing a key role in national economy. Short duration and high yielding varieties are always required for better quality and lint production. Early maturing crops avoid disease and pest epidemics due to which plant breeders have positioned adequate pressure on the development of early maturing crop plants (Singh, 2004). Term earlin...

The objective of the present study was to correlate the genetic distances (GD) of single cross hybrids with yield, heterosis and specific combining ability (SCA) in the double cross hybrid synthesis. For this, 10 single cross commercial hybrids were used from different companies, and all the possible double hybrids were synthesized by a complete dialell. The hybrids were assessed in 15 location...

HE phenomenon of heterosis has generally been studied in relation to some Tarbitrarily selected trait such as size, weight, or yield. Heterosis is then regarded as being manifested by an increase in the chosen trait. Although various definitions have been proposed ( GOWEN 1952), heterosis is most commonly and most meaningfully defined as an increase in the chosen trait in crossbred individuals ...

European water frog hybrids Rana esculenta (Rana ridibunda x Rana lessonae) reproduce hemiclonally, transmitting only their ridibunda genome to gametes. We compared fitness-related larval life-history traits of natural R. esculenta from Poland with those of the two sympatric parental species and of newly generated F1 hybrids. Compared with either parental species, F1 hybrid offspring had higher...

The study was carried out to estimate magnitude of heterosis over better parent and standard check for some important characters in 15 crosses resulting from a half diallel mating design of 6 inbred lines of brinjal. Hybrid variety ‘Tarapuri’ was used as standard check. The parents and the hybrids were evaluated at the farm of Olericulture Division, HRC, BARI, during the winter season of 2008-2...

The influence of different levels of adjusted fat thickness (AFT) and HCW slaughter end points (covariates) on estimates of breed and retained heterosis effects was studied for 14 carcass traits from serially slaughtered purebred and composite steers from the US Meat Animal Research Center (MARC). Contrasts among breed solutions were estimated at 0.7, 1.1, and 1.5 cm of AFT, and at 295.1, 340.5...

M A N Y hybrids between genetic pure lines in maize exhibit heterosis. The search for the genetic basis of heterosis has been carried on for many years and by many workers. Despite these efforts, an adequate, specific biochemical explanation of heterosis has not been presented. JONES (1952) has noted the interaction of nuclear genes and cytoplasm, as evidenced by differences in reciprocal cross...

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...