DNA methylation is an important regulatory mechanism for gene expression that involved in the biological processes of development and differentiation in plants. To investigate the association of DNA methylation with heterosis in Brassica, a set of intraspecific hybrids in Brassica rapa and B. napus and interspecific hybrids between B. rapa and B. napus, together with parental lines, were used t...

Heterosis and combining ability for total number of eggs laid per female silkworm Bombyx mori L were investigated in a six parent diallel crossing programme in four rearing seasons. Magnitude of heterosis varied from seasons to season and was not consistent over characters. Effect of season was important in the expression of genetic variances and other parameters studied. Considerable amount to...

Heterosis is a widespread phenomenon corresponding to the increase in fitness following crosses between individuals from different populations or lines relative to their parents. Its genetic basis has been a topic of controversy since the early 20th century. The masking of recessive deleterious mutations in hybrids likely explains a substantial part of heterosis. The dynamics and consequences o...

We constructed 128 chromosome segment substitution lines (CSSLs), derived from a cross between indica rice (Oryza sativa L.) 9311 and japonica rice Nipponbare, to investigate the genetic mechanism of heterosis. Three photo-thermo-sensitive-genic male sterile lines (Guangzhan63-4s, 036s, and Lian99s) were selected to cross with each CSSL to produce testcross populations (TCs). Field experiments ...

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...

Heterosis is a fundamental biological phenomenon characterized by the superior performance of a hybrid over its parents in many traits, but the underlying molecular basis remains elusive. To investigate whether DNA methylation plays a role in heterosis, we compared at single-base-pair resolution the DNA methylomes of Arabidopsis thaliana Landsberg erecta and C24 parental lines and their recipro...

HE dominant favorable gene hypothesis, first proposed by BRUCE (1910), T attributes heterosis to accumulated effects of loci at which the more favorable allele contributed by one parent is manifest rather than the unfavorable allele contributed by the other parent. The concepts of linkage (JONES 191 7) and large number of loci (COLLINS 1921; SINGLETON 1941) make the hypothesis compatible with t...

Five faba bean genotypes (Vicia faba L.) were selfed for two cycles to produce S1 and S2 generations. A half-diallel cross was carried out among them in each level of inbreeding (S0, S1 and S2) to obtain 10 F1 hybrids. Parental materials as well as their respective F1s were evaluated during the winter season of 2012. All studied traits except total dry seed yield showed significant inbreeding d...

Heterosis is a main contributor to yield increase in many crop species. Different mechanisms have been proposed for heterosis: dominance, overdominance, epistasis, epigenetics, and protein metabolite changes. However, only limited examples of molecular dissection and validation of these mechanisms are available. Here, we present an example of discovery and validation of heterosis generated by a...