The Plant Line command creates a freehand plant line along a line, polyline, or polygon. It can be used to represent a single undefined plant, line of plants, or general plant mass. … To create a plant line: Select the object (line, polyline, or polygon) with the Selection tool.

What is a line B line and R line?

A line is the cytoplasm-genetic male sterile line where the male sterility is jointly controlled by recessive nuclear gene and sterile cytoplasm. B-line is isogenic line of A-line, only difference in male sterility and fertility. R-line possesses fertility restoration gene [2].

What is a line variety?

A line can vary in width, direction, curvature, length and even color. Have students suggest different names of lines and demonstrate all the different types you can think of together. (Straight, curved, bent, zig-zag, curly, wavy, thin, fat, etc. – then be sure to explain horizontal, vertical and diagonal.)

What is line breeding in biology?

Linebreeding is a form of inbreeding that involves selection of mates on the basis of their relationships to a certain superior ancestor. The backcross (crossing a first-generation hybrid with one of the parental types) is a common method of inbreeding.

What do you mean by plant introduction?

Plant introduction is defined as a process of introducing plants in the new locality from their own growing locality which may involve wild or totally new variety of crops for the area or you can say a genotype or the group of genotypes are introduced. … Examples are- dwarf wheat varieties and dwarf rice varieties.

What is male-sterile line?

The male-sterile line is maintained by crossing with a maintainer line carrying the same nuclear genome but with normal fertile cytoplasm. For crops such as onions or carrots where the commodity harvested from the F1 generation is vegetative growth, male sterility is not a problem.

How do you selectively breed plants?

A plant is first selected by identifying the plant with phenotype of interest, such that good genes combination for desirable trait are picked out. The plant is then allowed to grow and self fertilise or cross fertilise with other plants of similar phenotype of interest.

What is R line in genetics?

R line: This line has restorer genes in nucleus to restore fertility of A line. R line is entirely different to that A and B line. R line has very high SCA (Specific Combining Ability) effects. It is used to produce hybrid seeds.

What is two-line breeding system?

The second is the two-line male sterility system that uses a genetic male sterile which is controlled by temperature, photoperiod or both. The use of this system is increasing due to the ease in breeding, finding more heterotic combinations, and in seed multiplication of parental male sterile lines.

Why is line breeding important in agriculture?

The idea of line breeding is to concentrate specific genetic traits into the herd. … He views line breeding as an important part of that effort because it prevents the need to regularly bring in bulls from other herds.

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What is meant by pure line?

Medical Definition of pure line : a homogeneous line of descent: as. a : a group of closely related individuals of identical genetic constitution (as the offspring of a homozygous self-fertilized parent) : a line of descent theoretically realizable from the inbreeding of completely homozygous and comparable parents.

What is synthetic breeding?

Synthetic is a term often used to describe a population that is developed by allowing cross-pollination to occur for several generations among a number of different cultivars, such as inbreds. … Public corn breeders have developed many improved populations.

What is progeny test in plant breeding?

A progeny test is performed by mating the male with a number of females to produce many progenies in a different environment and over a long time period involving different seasons to nullify the impact of season, management and environment in breeding value estimation. …

What type of lines are in art?

There are 5 main types of lines in art: vertical lines, horizontal lines, diagonal lines, zigzag lines, and curved lines. Other types of lines are simply variations of the five main ones.

What is plant introduction and acclimatization?

Plant introduction and acclimatization is the easiest and quickest method of crop improvement Plant introduction is defined as the process of introducing plants from their growing locality to a new locality. In this process, plants are transferred from their original habitat to a place having different climate.

What are the two types of plant introduction?

Types of Plant Introductions: • Based on adaptation, introductions are of two types, viz. 1 Primary Introduction • 2 Secondary Introduction • Based on utilization, again introduction are of two types, viz. (i) Direct introduction • (ii) Indirect Introduction.

Who developed the concept of pure line?

In the early twentieth century, Wilhelm Johannsen proposed his pure line theory and the genotype/phenotype distinction, work that is prized as one of the most important founding contributions to genetics and Mendelian plant breeding.

What are 4 examples of selective breeding?

• cows that produce lots of milk.
• chickens that produce large eggs.
• wheat plants that produce lots of grain.

Why do we selectively breed?

The purpose of selective breeding is to develop livestock whose desirable traits have strong heritable components and can therefore be propagated.

What are the three types of selective breeding?

The three methods of selective breeding are outcrossing, inbreeding and line breeding.

What is a maintainer line in plant breeding?

In a maintainer line (M), its cytoplasm is male fertile (normal) which interacts with a recessive male-sterile nuclear gene to jointly perform male-fertile phenotype.

How do men get sterile lines?

Cytoplasmic male sterile lines are propagated via cross-pollination by corresponding maintainer lines, whereas PTGMS lines are propagated via self-pollination under environmental conditions restoring male fertility.

Why male sterility is used in plant breeding?

In this sense, the use of male sterility reduces the cost of hybrid seed production for several reasons. It avoids hand emasculation and pollination, accelerating the hybrid breeding programs and allowing the large-scale production of hybrid seeds and the commercial exploitation of hybrid vigor (12).

How are two line systems helpful in hybrid seed production?

1. In two-line hybrid seed production, the two safe-periods refers to.
2. the useful atmospheric conditions that support first the induction of.
3. absolute male sterility and second the facilitation of proper pollen.
4. movement from the pollen parent and fertilization of the TGMS.

Which line is also called as seed parent in hybrid seed production?

Like in other crops, the first generation progeny (F1) obtained by crossing two genetically different varieties (parents) of rice is called ‘Hybrid’. … It is generally referred to as ‘R’ line, and is used for hybrid seed production.

How do you develop a CMS line?

The stable CMS lines could be developed by selecting the maintainer plants that are tolerant to temperature fluctuations, by eliminating the modifier gene(s) through maintainer plant selection and by screening the progeny under low temperature conditions for maximum expression of the trait (Gniffke et al. 2009).

What is Threeline breeding?

Since then, CMS-WA has been introgressed into a variety of rice backgrounds to produce numerous CMS lines, and based on these lines, the “three-line” (male-sterile line, maintainer line, and restorer lines) hybrid breeding system was developed and widely used in China (thus named the “first-generation” hybrid rice).

What is two line breeding system in rice?

The two-line system for hybrid breeding is more efficient than the three-line system for exploiting heterosis in rice to increase the yield per unit area. Three PGMS genes and five TGMS genes have been identified by scientists from China, Japan, IRRI, Vietnam, and India.

How does line breeding work?

What is linebreeding? Linebreeding is a term commonly used to describe milder forms of inbreeding. Typically it involves arranging matings so that one or more relatives occur more than once in a pedigree, while avoiding close inbreeding.

Are Inbreds deformed?

Additionally, consanguineous parents possess a high risk of premature birth and producing underweight and undersized infants. Viable inbred offspring are also likely to be inflicted with physical deformities and genetically inherited diseases.

What are the disadvantages of line breeding?

• Lower fertility.
• Lower “vigor”
• Birth defects.
• Smaller size.
• Fewer offspring.
• Slower growth.
• Higher offspring mortality.
• Shorter lifespan.