What Does Plant Breeding’S Heterosis Mean?

Plant breeding is the application of genetic principles to develop new plant varieties, known as cultivar development, crop improvement, and seed improvement. Heterosis in plant breeding refers to the superiority of an F1 hybrid over both parents in terms of yield or other characteristics. Heterosis is a pillar of global food security and is an expected consequence of whole-genome non-additive effects at the population level over evolutionary time. Understanding heterosis from the perspective of molecular genetics would revolutionize modern plant breeding by allowing the optimal exploitation of crop.

Heterosis, also known as hybrid vigor, refers to the phenomenon that heterozygous hybrids show superior performance over their parents. This phenomenon is quite beneficial for plants on various levels. Heterosis has historically been exploited in plants, but its underlying genetic mechanisms and molecular basis remain elusive. In recent years, due to the increasing number of gametes inherited in polyploids, progressive heterosis is expected.

In breeding, heterosis refers to the idea that a hybrid has greater genetic strength than organisms of a homogeneous background. It is a common biological phenomenon in nature and can be explained by various models, including dominance, overdominance, and pseudo-overdominance. Progressive heterosis is expected in polyploids because the number of gametes inherited exceeds the number of parents.

In summary, heterosis, also known as hybrid vigor, is a phenomenon where a progeny exhibits superior traits relative to one or both parents. It is a common biological phenomenon in nature and contributes to global food security.

What is heterosis and inbreeding?

Heterosis, or hybrid vigor, is a breeding technique that enhances characteristics in offspring by crossing two genetically different parents. It occurs when two parents have different genetic backgrounds, leading to a higher fitness level in the offspring. Inbreeding depression, on the other hand, is a reduction in fitness due to inbreeding. Both techniques are used by breeders to obtain traits and characteristics that suit their needs, but they can either enhance or reduce the fitness of offspring.

What are the three types of heterosis?

Heterosis is a genetic trait that refers to the superiority of an F1 hybrid over its parents in one or more characteristics. It is often seen as desirable, but in some cases, negative heterosis may be preferable. This can be seen in plant height, maturity time, and hazardous chemicals. In plant breeding, the application of genetic principles in cultivar development, crop improvement, and seed improvement is known as heterosis. Heterosis contributes to increased vigour, size, growth rate, yield, and other attributes.

In exceptional cases, the hybrid may be inferior to the weaker parent. The genetic basis of heterosis is also discussed. Positive heterosis is often seen as desirable, while negative heterosis is preferable in certain circumstances. In most agricultural plants, heterosis of 40 or more over the superior parent is considered substantial from a practical standpoint.

What is another name for heterosis?

Heterosis, or hybrid vigor, refers to the enhanced function of any biological quality in a hybrid offspring, which often includes traits beyond the simple addition of parents’ traits. These traits can be explained by Mendelian or non-Mendelian inheritance. Examples of heterotic/hybrid traits in agriculture include higher yield, quicker maturity, stability, and drought tolerance. G. H. Shull proposed the term heterosis to replace heterozygosis to avoid limiting it to effects explained by heterozygosity in Mendelian inheritance.

The physiological vigor of an organism is positively correlated with the degree of dissimilarity in the gametes by which it was formed. The more numerous the differences between the uniting gametes, the greater the stimulation, and these differences need not be Mendelian in their inheritance. To avoid implying that all genotypic differences stimulating cell division, growth, and other physiological activities are Mendelian in their inheritance and to gain brevity of expression, the term “heterosis” should be adopted.

What is the method of heterosis breeding?

Heterosis is a process where hybrids between inbred individuals show increased biomass and fertility, surpassing the better parent. This phenomenon is used in plant breeding to boost crop yields. ScienceDirect uses cookies and cookies are used by the site. Copyright © 2024 Elsevier B. V., its licensors, and contributors. All rights reserved, including text and data mining, AI training, and similar technologies. Creative Commons licensing terms apply for open access content.

What is the difference between heritability and heterosis?

Heterosis is a breeding system that aims to improve lowly heritable traits, such as reproduction, longevity, maternal ability, and health, by combining genetic and environmental effects. These traits respond slowly to selection, as the majority of variation is due to environment rather than genetics. Heterosis is an effective way to improve these traits.

Breed complementarity is another aspect of heterosis, where one breed excels in certain traits while the other does not. This results in progeny offering greater performance in more traits than their straight-bred parents. For example, a herd of crossbred Angus-Hereford cows mated to a Charolais bull can provide maternal capability and carcass quality advantages, while the Charolais bull can increase growth and carcass yield. This results in a maternally focused cow that is a good fit for her environment, while the high-growth calf can bring greater value to the marketplace.

There are various breeding systems that can effectively capture the benefits of heterosis, but some do not fit a common-sense ranch management plan. The average herd size in the United States is 40 cows, which limits the ability of producers to utilize crossbreeding systems. Additionally, management of breeding systems requiring multiple breeding pastures poses another obstacle. In an attempt to produce cattle that fall within the parameters of branded beef programs, many producers have trended toward straight-bred herds.

What are the benefits of heterosis breeding?

Heterosis is a common practice in the livestock industry, offering benefits in three forms: individual, maternal, and paternal. Retained heterosis refers to the increased performance of crossbred progeny compared to purebred parents. Maternal heterosis involves an increase in cow production above the average of her parent breeds, benefiting maternal ability, reproduction, longevity, calf survivability, and younger puberty age. Paternal heterosis is the genetic advantage provided by the sire, leading to increased bull fertility.

Lowly heritable traits, such as reproduction, longevity, maternal ability, and health, are the most significant impact of heterosis. These traits respond slowly to selection, as the majority of variation is due to environment rather than genetics. Heterosis is an effective way to improve these lowly heritable traits.

Breed complementarity is another important aspect of heterosis. When one breed excels in certain traits, the other breed does not, and vice versa. Successful mating results in progeny with greater performance in more traits than straight-bred parents. This helps match cattle genetically to their environment and the resulting progeny to the marketplace. For example, a herd of crossbred Angus-Hereford cows mated to a Charolais bull offers maternal capability and carcass quality advantages, while the Charolais bull increases growth and carcass yield.

What is the function of heterosis?

Heterosis is the superior growth, development, yield, and environmental adaptation of an F1 hybrid compared to its inbred parents. It has been instrumental in improving crop yields worldwide for about a century and ensuring food security for humans. This concept is governed by copyright © 2024 Elsevier B. V., its licensors, and contributors, and is applicable to text and data mining, AI training, and similar technologies.

What are the advantages of heterosis in plant breeding?

Heterosis is a phenotype in plants where F 1 hybrids between specific combinations of parental lines show superior performance compared to the parental lines. This concept was first described by Charles Darwin in his work on cross and self-fertilization in the vegetable kingdom. George Harrison Shull introduced the term “heterosis” in 1914 to describe the superior performance of hybrids, which can be seen in biomass, yield, and abiotic and biotic stress tolerance. Heterosis is used in breeding F 1 hybrid cultivars in various crops and vegetables.

In 1909, George Harrison Shull discovered increased grain yields in hybrid corn and proposed this as a method of corn breeding. This led to the transition from open-pollinated to four-way cross hybrids (double cross hybrid) and then to two-way cross hybrids (single cross hybrid). Hybrid corn became the main crop in the United States in the 1950s, with yields increasing from one ton per hectare in 1930 to four tons per hectare in 1960 and approximately twelve tons per hectare in 2017.

Hybrids are also used in crops such as sorghum, sunflower, canola, and various vegetables. Attempts have been made to produce hybrid seed in wheat. However, the underlying biological mechanisms of heterosis are not well understood, and recent research aims to clarify this mystery.

What are the disadvantages of heterosis?

The full utilization of heterosis in crop reproductive biology faces technical issues like difficulties in generating and maintaining male-sterile lines and low efficiency of natural cross-pollination for certain genetic combinations. These issues are related to crop reproductive biology and are addressed through the use of cookies on ScienceDirect. All rights reserved, including those for text and data mining, AI training, and similar technologies, with Creative Commons licensing terms applicable for open access content.

Why is heterosis so important?

Heterosis is a phenomenon where traits with the lowest heritability are most susceptible to environmental variation, resulting in the highest benefits for reproductive and fitness performance. This includes embryo survival, litter size born, and neonatal survival. The use of cookies on this site is governed by copyright © 2024 Elsevier B. V., its licensors, and contributors. All rights reserved, including those for text and data mining, AI training, and similar technologies.

What is the best parent heterosis?

The terms midparent heterosis (MPH) and best parent heterosis (BPH) are used to describe the phenotypic difference observed in a hybrid (F1) when compared to its parental inbred lines (P1, P2). The aforementioned terms are employed by ScienceDirect for the purpose of furnishing pertinent information pertaining to shopping carts, contact and support, terms and conditions, privacy policy, and cookies. Copyright © 2024 Elsevier B. V., as the licensor and contributor.