Ans: Triploidy is a desirable trait in all angiosperms except orchidaceae and Triploidy could be a desirable trait in agricultural species where the economic part especially fruits. Triploid hybrids have one of the most important traits, seedlessness, which is the characteristic for the fresh-fruit market. Triploid embryos are found in small seeds that do not germinate. Triploid plants raised from endosperm are generally sterile. Endosperm-raised triploid plants are of commercial value, e.g. timber-yielding plants, edible fruit plants or ornamentals propagated vegetatively and multiplied mainly through micropropagation. Triploid plants often show vigorous vegetative growth and in some species produce excellent seedless fruit. All cultivated bananas are triplods, and must be propagated vegetatively as they bear no seed. Some sugar beet varieties are triploid and these tend to be higher yielding than diploid varieties. In some species it is not desirable as they produce little or no seed, each generation of a triploid variety has to be made afresh by the hybridization of a diploid and a tetraploid parent. Eg: Commercial use of triploid fruits can be found in watermelons and are produced artificially by first developing tetraploids whicg are then crossed with diploid watermelon. In order to set fruit, the triploid watermelon crossed with desirable diploid pollen donar. It is an undesirable trait In some species it is not desirable as they produce little or no seed (may be sterile because they cannot form gametes with a balanced assortment of chromosomes), each generation of a triploid variety has to be made afresh by the hybridization of a diploid and a tetraploid parent. Eg: Diana\' (1963, USA) has large single, pure white petals with crimped edges. It is a triploid, so produces little or no viable seed, and thus continues to flower over a long period. It was followed in the 1980s by more triploid cultivars, in particular \'Aphrodite\' polyploidy leads to significant reduction in the amount of genetic diversity in some species. As genetically identical clones, a pest or disease that affects one individual is likely capable of affecting each of its clones. Eg: vast majority of commercially produced bananas are cloned from a single source, the Cavendish cultivar, and those plants are currently threatened worldwide by a newly discovered fungal disease to which they are highly susceptible. It is an undesirable trait in crop species where the economic part is seed Example : Orchidacea The Phalaenopsis species bear a very brightly colored and patterned flowers were reintroduced into cultivation. Many of these novelty species however produce inflorescences with only a very few, tiny, starry-shaped flowers. These diploid species have been crossed with the modern autopolyploid white types to improve their size, form, and floriferousness. In many instances, these characteristics were improved but flower color was substantially diluted. In addition, many .

1. Ans:
Triploidy is a desirable trait in all angiosperms except orchidaceae and Triploidy could be a
desirable trait in agricultural species where the economic part especially fruits. Triploid hybrids
have one of the most important traits, seedlessness, which is the characteristic for the fresh-fruit
market. Triploid embryos are found in small seeds that do not germinate. Triploid plants raised
from endosperm are generally sterile. Endosperm-raised triploid plants are of commercial value,
e.g. timber-yielding plants, edible fruit plants or ornamentals propagated vegetatively and
multiplied mainly through micropropagation.
Triploid plants often show vigorous vegetative growth and in some species produce excellent
seedless fruit. All cultivated bananas are triplods, and must be propagated vegetatively as they
bear no seed. Some sugar beet varieties are triploid and these tend to be higher yielding than
diploid varieties. In some species it is not desirable as they produce little or no seed, each
generation of a triploid variety has to be made afresh by the hybridization of a diploid and a
tetraploid parent.
Eg: Commercial use of triploid fruits can be found in watermelons and are produced artificially
by first developing tetraploids whicg are then crossed with diploid watermelon. In order to set
fruit, the triploid watermelon crossed with desirable diploid pollen donar.
It is an undesirable trait
In some species it is not desirable as they produce little or no seed (may be sterile because they
cannot form gametes with a balanced assortment of chromosomes), each generation of a triploid
variety has to be made afresh by the hybridization of a diploid and a tetraploid parent.
Eg: Diana' (1963, USA) has large single, pure white petals with crimped edges. It is a triploid,
so produces little or no viable seed, and thus continues to flower over a long period. It was
followed in the 1980s by more triploid cultivars, in particular 'Aphrodite'
polyploidy leads to significant reduction in the amount of genetic diversity in some species. As
genetically identical clones, a pest or disease that affects one individual is likely capable of
affecting each of its clones. Eg: vast majority of commercially produced bananas are cloned from
a single source, the Cavendish cultivar, and those plants are currently threatened worldwide by a
newly discovered fungal disease to which they are highly susceptible.
It is an undesirable trait in crop species where the economic part is seed Example : Orchidacea
The Phalaenopsis species bear a very brightly colored and patterned flowers were reintroduced
into cultivation. Many of these novelty species however produce inflorescences with only a very
few, tiny, starry-shaped flowers. These diploid species have been crossed with the modern
autopolyploid white types to improve their size, form, and floriferousness. In many instances,
these characteristics were improved but flower color was substantially diluted. In addition, many

2. of these hybrids were triploid and were almost completely sterile.
The major limitation in using orchid hybrids in a breeding program is not due to their hybridity
but to the result of triploidy. One would expect that the fertility of a specific triploid should vary
depending upon the environment. This seems to be the case. In general it was found that triploid
Solution
Ans:
Triploidy is a desirable trait in all angiosperms except orchidaceae and Triploidy could be a
desirable trait in agricultural species where the economic part especially fruits. Triploid hybrids
have one of the most important traits, seedlessness, which is the characteristic for the fresh-fruit
market. Triploid embryos are found in small seeds that do not germinate. Triploid plants raised
from endosperm are generally sterile. Endosperm-raised triploid plants are of commercial value,
e.g. timber-yielding plants, edible fruit plants or ornamentals propagated vegetatively and
multiplied mainly through micropropagation.
Triploid plants often show vigorous vegetative growth and in some species produce excellent
seedless fruit. All cultivated bananas are triplods, and must be propagated vegetatively as they
bear no seed. Some sugar beet varieties are triploid and these tend to be higher yielding than
diploid varieties. In some species it is not desirable as they produce little or no seed, each
generation of a triploid variety has to be made afresh by the hybridization of a diploid and a
tetraploid parent.
Eg: Commercial use of triploid fruits can be found in watermelons and are produced artificially
by first developing tetraploids whicg are then crossed with diploid watermelon. In order to set
fruit, the triploid watermelon crossed with desirable diploid pollen donar.
It is an undesirable trait
In some species it is not desirable as they produce little or no seed (may be sterile because they
cannot form gametes with a balanced assortment of chromosomes), each generation of a triploid
variety has to be made afresh by the hybridization of a diploid and a tetraploid parent.
Eg: Diana' (1963, USA) has large single, pure white petals with crimped edges. It is a triploid,
so produces little or no viable seed, and thus continues to flower over a long period. It was
followed in the 1980s by more triploid cultivars, in particular 'Aphrodite'
polyploidy leads to significant reduction in the amount of genetic diversity in some species. As
genetically identical clones, a pest or disease that affects one individual is likely capable of
affecting each of its clones. Eg: vast majority of commercially produced bananas are cloned from
a single source, the Cavendish cultivar, and those plants are currently threatened worldwide by a
newly discovered fungal disease to which they are highly susceptible.

3. It is an undesirable trait in crop species where the economic part is seed Example : Orchidacea
The Phalaenopsis species bear a very brightly colored and patterned flowers were reintroduced
into cultivation. Many of these novelty species however produce inflorescences with only a very
few, tiny, starry-shaped flowers. These diploid species have been crossed with the modern
autopolyploid white types to improve their size, form, and floriferousness. In many instances,
these characteristics were improved but flower color was substantially diluted. In addition, many
of these hybrids were triploid and were almost completely sterile.
The major limitation in using orchid hybrids in a breeding program is not due to their hybridity
but to the result of triploidy. One would expect that the fertility of a specific triploid should vary
depending upon the environment. This seems to be the case. In general it was found that triploid