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...

Heterosis is widely used in breeding, but the genetic basis of this biological phenomenon has not been elucidated. We postulate that additive and dominance genetic effects as well as two-locus interactions estimated in classical QTL analyses are not sufficient for quantifying the contributions of QTL to heterosis. A general theoretical framework for determining the contributions of different ty...

Antibiosis-based resistance to two insect pests of rice, Nilaparvata lugens (Stål) (Hemiptera: Delphacidae) and Marasmia patnalis Bradley (Lepidoptera: Pyralidae), was compared in 11 F1 hybrids and their parental lines. Our objective was to determine whether hybrids show heterosis (hybrid vigor) for insect resistance or susceptibility. Heterosis is defined as the amount by which a hybrid exceed...

Antibiosis-based resistance to two insect pests of rice, Nilaparvata lugens (Stål) (Hemiptera: Delphacidae) and Marasmia patnalis Bradley (Lepidoptera: Pyralidae), was compared in 11 F1 hybrids and their parental lines. Our objective was to determine whether hybrids show heterosis (hybrid vigor) for insect resistance or susceptibility. Heterosis is deÞned as the amount by which a hybrid exceeds...

Arabidopsis thaliana shows hybrid vigor (heterosis) in progeny of crosses between Columbia-0 and C24 accessions. Hybrid vigor was evident as early as mature seeds and in seedlings 3 d after sowing (DAS). At 3 DAS, genes encoding chloroplast-located proteins were significantly overrepresented (187) among the 724 genes that have greater than midparent values of expression in the hybrid. Many of t...

Heterosis is defined as the superiority of a hybrid cross over its two parents. Plant and animals breeders have long been exploiting heterosis, but the causes of this phenomenon are as yet only partly understood. Recently, chip technology has opened up the opportunity to study heterosis at the gene expression level. This article considers the cDNA chip technology, which allows assaying two geno...

The phenomenon of heterosis describes the increased agronomic performance of heterozygous F(1) plants compared to their homozygous parental inbred plants. Heterosis is manifested during the early stages of root development in maize. The goal of this study was to identify nonadditive gene expression in primary roots of maize hybrids compared to the average expression levels of their parental inb...

Primary causes of heterosis are still unknown. Our goal was to investigate the extent and underlying genetic causes of heterosis for five biomass-related traits in Arabidopsis thaliana. We (i) investigated the relative contribution of dominance and epistatic effects to heterosis in the hybrid C24 x Col-0 by generation means analysis and estimates of variance components based on a triple testcro...

The molecular basis of hybrid vigor (heterosis) has remained unknown despite the importance of this phenomenon in evolution and in practical breeding programs. To formulate a molecular basis of heterosis, an understanding of gene expression in inbred and hybrid states is needed. In this study, we examined the amount of various transcripts in hybrid and inbred individuals (B73 and Mo17) to deter...

In this article we investigate multiplicative effects between genes in relation to heterosis. The extensive literature on heterosis due to multiplicative effects between characters is reviewed, as is earlier work on the genetic description of heterosis. A two-locus diallelic model of arbitrary gene action is used to derive linear parameters for two multiplicative models. With multiplicative act...