Ten tomato commercial and productive single cross hybrids extensively grown in Northern Transitional Zone of Karnataka were planted in the field at UAS, Dharwad following RBD design with three replications. A 10 x 10 diallel set was generated by crossing these single cross hybrids in all possible combinations (excluding reciprocals) and 45 double cross hybrids were planted during February, 2007...

The use of heterosis has considerably increased the productivity of many crops; however, the biological mechanism underpinning the technique remains elusive. The North Carolina design III (NCIII) and the triple test cross (TTC) are powerful and popular genetic mating design that can be used to decipher the genetic basis of heterosis. However, when using the NCIII design with the present quantit...

Rice (Oryza sativa L.) is the most important food crop of the world; but drought stress is a serious limiting factor to rice production and yield stability in rainfed areas. Breeding for drought tolerance is a challenging task because of the complexicity of the component traits, screening technique, environmental factors and their interaction. The major setback in drought tolerance breeding is ...

The application of heterosis (hybrid vigor) has brought great success to plant breeding, particularly of hybrid rice, achieving significant yield increases. Attempts to explore the heterosis of inter-subspecific hybrids between indica and japonica rice, which result in even greater yield increases, have greatly increased in the past decades. However, because of the reduced seed setting rate in ...

Ewe performance was compared for five pure breeds of sheep (Finnsheep, F; Rambouillet, R; Dorset, D; Targhee, T; Suffolk, S) and the crosses in development of two maternal composite lines (C1 = 1/2F1/4R1/4D and C2 = 1/2F1/4T1/4S). The data involved 10,959 breeding season records of 4,219 ewes by 412 sires. Ewe production and the components (fertility, litter size, neonatal and preweaning lamb s...

The objective of this study was to estimate the breed, heterosis, and recombination effects on different components lactation curve Girolando cattle. dataset used consisted 12,121 purebred cows Holstein (H) Gyr (G) breeds, six H×G crossbred (Girolando). model presents random herd cow, regression coefficient associated with linear effect proportion H heterosis between G [...]

The study was performed on 4 609 ejaculates obtained from 32 boars, including 14 purebred and 18 two-breed crosses. The ejaculates were collected manually every 4-5 days. The study involved ejaculates collected from each boar from the first day of its insemination use until the day of semen depletion. Each ejaculate was assessed for the following physical parameters: ejaculate volume, sperm con...

Cooperative groups can increase fitness either by helping kin or interacting with unlike individuals to produce social heterosis. They cannot, however, simultaneously maximize both benefits. This tradeoff between nepotism and diversity is modeled using Hamilton’s rule (rb–c > 0), by allowing benefit and cost to be dynamic functions of relatedness (i.e., social heterosis predicts b and c depend ...

Performance of six genetic groups of mice was studied in three different environments in order to determine the effect of heterosis on consistency of performance in varied environments. Designed as a 3 x 6 factorial, data were analyzed using least squares analyses of variance. Genetic group effects, environmental effects, genetic group x environment interaction, and heterosis were examined for ...

The genetic basis of hybrid vigor or heterosis has been debated for more than a century. A popular hypothesis to explain this phenomenon is that there are different slightly deleterious recessive homozygous alleles in the two parents and that these alleles are complemented in the hybrid so that the biomass and fertility exceed both parents. To address the complementation hypothesis in a direct ...