Method of Plant Breeding Questions in English

(N/A) Mutation is the process by which genetic variations are created through changes in the base sequence within genes,resulting in the creation of a new character or trait not found in the parental type.
It is possible to induce mutations artificially through the use of chemicals or radiations (like $\gamma$ radiations) and selecting and using the plants that have the desirable character as a source in breeding; this process is called mutation breeding.
Several wild relatives of different cultivated species of plants have been shown to have certain resistant characters but have very low yield.
Hence,there is a need to introduce the resistant genes into the high-yielding cultivated varieties. Resistance to yellow mosaic virus in bhindi $(Abelmoschus esculentus)$ was transferred from a wild species and resulted in a new variety of $A. esculentus$ called Parbhani Kranti.
All the above examples involve sources of resistance genes that are in the same crop species,which has to be bred for disease resistance,or in a related wild species.
Transfer of resistance genes is achieved by sexual hybridisation between the target and the source plant followed by selection.

(N/A) Gamma rays are a form of ionizing radiation used in mutation breeding to induce genetic variability in crops.
They are used under controlled laboratory or field conditions to treat seeds or plant tissues.
These rays do not remain in the plant or the final food product,as they are a form of energy and not a chemical residue.
Therefore,they are not harmful to human health when consumed,provided the safety protocols are followed during the irradiation process to prevent direct exposure to the personnel involved.

(N/A) The man-made cereal is $Triticale$.
It was developed by crossing $Triticum$ $aestivum$ (wheat) and $Secale$ $cereale$ (rye).
This hybrid combines the high yield and grain quality of wheat with the hardiness and disease resistance of rye.
It is primarily used as animal feed,though it is also used in some human food products like flour for baking.

(N/A) $(i)$ Plant hybridization programme is often constrained by the availability of a limited number of disease resistance genes that are present in various crop varieties or wild relatives.
$(ii)$ Several wild relatives of different cultivated species of plants have been shown to have certain resistant characters but have very low yield.

(N/A) $(i)$ $M.S.$ Swaminathan developed short-duration,high-yielding varieties of rice,including scented $Basmati$.
$(ii)$ He is also known for the development of the concept of crop cafeteria,crop scheduling,and genetically improving crop yield and quality.

(N/A) The term 'desirable trait' refers to specific characteristics that breeders aim to introduce into crop varieties to improve yield,quality,or survival. These traits vary depending on the plant species and the environmental challenges they face:
$1$. In millets,resistance to water stress (drought) is a highly desirable trait because these crops are often grown in arid or semi-arid regions.
$2$. In mung bean,resistance to yellow mosaic virus and powdery mildew are considered desirable traits,as these diseases significantly reduce crop yield and quality.

(N/A) The collection of diverse alleles of all the genes of a crop plant is called germplasm collection.
It is of great benefit in plant breeding programmes as it offers breeders the entire set of genes and alleles,along with the characteristics they express.
The breeder selects the most favourable traits from these genes and manipulates their transfer to a desirable parent to develop improved varieties.

(D) The improved characteristics of wheat that contributed to the Green Revolution in India include:
$(i)$ Semi-dwarf nature,which prevents lodging and allows for higher fertilizer response.
$(ii)$ Quick-yielding feature,which allows for multiple cropping cycles.
$(iii)$ High-yielding feature,which significantly increased the total grain production per hectare.
$(iv)$ Disease-resistant feature,which protects the crop from various pathogens and pests.

(N/A) The morphological and biochemical features of plants that provide resistance against insect and pest infestation include:
$(i)$ Increasing hair growth on aerial parts of plants (hairy leaves),which prevents insect attachment and feeding.
$(ii)$ Rendering the flowers nectar-less,which discourages pollinators or insects that feed on nectar.
$(iii)$ Enabling plants to secrete insect-killing chemicals (toxins),such as the production of aspartic acid,low nitrogen,and low sugar content in maize,which makes them resistant to stem borers.

(N/A) The newly selected plant lines are evaluated for their yield and other agronomic traits such as quality and disease resistance.
This evaluation is initially conducted in research fields under ideal conditions,including optimal fertilizer application,irrigation,and crop management practices.
Following this,the materials are tested in farmers' fields for at least three growing seasons across various locations in the country.
These locations are chosen to represent all the agroclimatic zones where the crop is typically cultivated.
Finally,the performance of the new variety is evaluated by comparing it with the best available local crop cultivar,which serves as a check or reference cultivar.

(N/A) The development of a new genetic variety of a crop involves several systematic steps:
$1$. Collection of Variability: Genetic variability is the root of any breeding program. Pre-existing genetic variability is collected from wild relatives and landraces of the crop.
$2$. Evaluation and Selection of Parents: The germplasm is evaluated to identify plants with desirable traits. These plants are then multiplied and used in the process of hybridization.
$3$. Cross Hybridization among the Selected Parents: This involves crossing two plants with different desirable traits (e.g.,high protein quality from one parent and disease resistance from another) to combine the traits into one progeny.
$4$. Selection and Testing of Superior Recombinants: This step involves selecting those progeny plants that have the desired combination of traits. This is a crucial and scientifically demanding process,often involving self-pollination for several generations to achieve homozygosity.
$5$. Testing,Release,and Commercialization of New Cultivars: The selected lines are evaluated for yield and other agronomic traits of quality,disease resistance,etc.,in research fields and then in farmers' fields for at least three growing seasons at several locations. Finally,the material is certified and released as a new variety.

(A) The correct matches based on crop varieties developed for disease resistance are:
$(a)$ Mustard: The variety developed for resistance to aphids is $Pusa$ $Gaurav$ $(a-3)$.
$(b)$ Flat bean: The variety developed for resistance to jassids, aphids, and fruit borer is $Pusa$ $Sem$ $2$ $(b-4)$.
$(c)$ Okra: The variety developed for resistance to shoot and fruit borer is $Pusa$ $Sawani$ $(c-1)$.
Therefore, the correct matching is $(a-3, b-4, c-1)$.

(C) The process of plant breeding for creating genetically diverse crop varieties follows a specific sequence of steps:
$1$. Collection of variability $(iii)$: Genetic variability is the root of any breeding program.
$2$. Evaluation and selection of parents $(ii)$: The collected germplasm is evaluated to identify plants with desirable traits,which are then selected as parents.
$3$. Cross-hybridization among the selected parents $(v)$: The selected parents are crossed to combine the desired traits into one progeny.
$4$. Selection and testing of superior recombinants $(i)$: The progeny is evaluated to select those that possess the desired combination of characters.
$5$. Testing,release,and commercialization of new cultivars $(iv)$: The selected superior lines are tested in research fields and farmers' fields before being released as new varieties.
Thus,the correct sequence is $(iii) \rightarrow (ii) \rightarrow (v) \rightarrow (i) \rightarrow (iv)$.

(D) The entire collection of plants/seeds having all the diverse alleles for all genes in a given crop is called germplasm collection.
This collection serves as the fundamental resource for plant breeding programs,providing the necessary genetic variability required for crop improvement.

(A) Parbhani Kranti is a specific variety of Okra $(Abelmoschus \text{ } esculentus)$ that was developed through plant breeding techniques. This variety is known for its resistance to yellow vein mosaic virus. Therefore, the correct option is $A$.

(A) Plant breeding is a systematic process to improve the quality and yield of crops. The steps involved in plant breeding are as follows:
$1$. Collection of variability: This is the first step where germplasm (the entire collection of plants/seeds having all the diverse alleles for all genes in a given crop) is collected.
$2$. Evaluation and selection of parents: The collected germplasm is evaluated to identify plants with desirable traits,and these are selected as parents.
$3$. Cross-hybridization among the selected parents: The selected parents are crossed to combine desired characters.
$4$. Selection and testing of superior recombinants: Progeny are selected and tested for desired traits.
$5$. Testing,release,and commercialization of new cultivars: The final selected lines are evaluated for yield and other agronomic traits and then released as new varieties.
Therefore,germplasm collection is performed during the 'Collection of variability' step.

(D) The correct answer is $D$. $Jowar$ (Sorghum) is known for its resistance to stem borer insects. This trait is achieved through plant breeding techniques to enhance food production and reduce crop loss due to pests.

(C) In plant breeding,specific biochemical characteristics are selected to confer resistance against insect pests.
For maize,high aspartic acid content,low nitrogen content,and low sugar content are associated with resistance to stem borer insects.
Therefore,high aspartic acid is the correct characteristic among the given options.

(B) Norman Borlaug is known as the 'Father of the Green Revolution'. He developed semi-dwarf,high-yielding varieties of wheat,which played a crucial role in increasing food production globally,particularly in Mexico and India. Therefore,the correct option is $B$.

(A) In plant breeding,morphological characteristics are often used to confer resistance against pests.
Cotton plants with hairy leaves are known to be resistant to $Jassids$.
This is because the presence of hairs on the leaves acts as a physical barrier or deterrent,making it difficult for these specific insects to feed or lay eggs on the plant surface.

(D) The International Maize and Wheat Improvement Center,commonly known by its Spanish acronym $CIMMYT$ (Centro Internacional de Mejoramiento de Maíz y Trigo),is a non-profit research and training institution dedicated to the development of improved varieties of wheat and maize. It is headquartered in El Batán,Texcoco,which is located in Mexico. This center played a crucial role in the Green Revolution by developing high-yielding varieties of wheat.

(D) $IRRI$ stands for the International Rice Research Institute.
It is an international agricultural research and training organization headquartered in Los Baños,Philippines.
It was established in $1960$ with the goal of reducing poverty and hunger,improving the health of rice farmers and consumers,and ensuring environmental sustainability of rice farming.

(C) $IR-8$ is a semi-dwarf variety of rice that was developed at the International Rice Research Institute $(IRRI)$,which is located in the Philippines.
This variety was a significant breakthrough during the Green Revolution,as it provided high yields and was resistant to lodging.

(A) Sonalika and Kalyan Sona are high-yielding and disease-resistant varieties of wheat $(Triticum \text{ } aestivum)$.
These varieties were introduced in India during the mid-$1960s$ as part of the Green Revolution to increase food production.

(B) $Saccharum$ $officinarum$ (tropical sugar cane) is characterized by a thick stem and high sugar content. It grows well in South India. However,it does not grow well in North India due to climatic conditions. $Saccharum$ $barberi$ is the variety that grows well in North India. Therefore,the statement that it grows well in North India is incorrect for $Saccharum$ $officinarum$.

(C) According to the $NCERT$ textbook,the variety of Brassica (mustard) known as $Pusa \ Swarnim$ is resistant to the disease $White \ rust$. Therefore,$X = Pusa \ Swarnim$ and $Y = White \ rust$.

(C) Mutation breeding is a technique used to induce genetic variation in plants by exposing them to physical or chemical mutagens. This process can create new traits or alleles that were not previously present in the parent population,which can then be selected for crop improvement. Conventional breeding relies on existing genetic variation within the population,whereas mutation breeding artificially creates new variation.

(C) $Gamma$-rays are a type of ionizing radiation used in mutation breeding to induce genetic mutations in plants.
These mutations can lead to the development of new varieties with desirable traits such as disease resistance or higher yield.
Mutation breeding is a powerful tool used by plant breeders to create genetic variability when natural variation is limited.

(B) The correct answer is $B$.
$A$. esculentus (Abelmoschus esculentus) is the scientific name for Okra (Bhindi).
Pusa Sawani,Pusa Sem-$3$,and Pusa $A$-$4$ are specific varieties of crops developed through plant breeding for resistance to diseases and pests.
Pusa Sawani and Pusa $A$-$4$ are varieties of Okra (Bhindi),while Pusa Sem-$3$ is a variety of Flat bean.
Since $A$. esculentus represents the species name rather than a specific bred variety,it is the odd one out.

(B) The correct answer is $B$.
$1$. $Himgiri$ is a disease-resistant variety of wheat developed by hybridization and selection for disease resistance against leaf and stripe rust and hill bunt.
$2$. $Atlas-66$ is a wheat variety known for its high protein content.
$3$. $Sonalika$ is a high-yielding and disease-resistant variety of wheat.
$4$. $Pusa$ $Shubhra$ is a variety of cauliflower ($Brassica$ $oleracea$),not wheat. It is resistant to black rot and curd blight.

(D) Plant breeding for developing resistance to insect pests is a key strategy in agriculture.
In cotton,resistance to bollworms is associated with specific morphological and biochemical characteristics.
$(1)$ Hairy leaves $(ii)$ prevent the bollworms from laying eggs or feeding effectively.
$(2)$ Nectar-less varieties $(vi)$ are less attractive to bollworms as they lack the food source (nectar) that the pests require.
$(3)$ High aspartic acid,low nitrogen,and low sugar content in cotton leaves are also known to confer resistance.
Therefore,the combination of hairy leaves and nectar-less traits makes the cotton plant resistant to bollworms.

(A) The correct matches for crop varieties and their disease resistance are as follows:
$(a)$ Himgiri is a variety of wheat resistant to Hill bunt.
$(b)$ Pusa Komal is a variety of cowpea resistant to Bacterial blight.
$(c)$ Pusa Snowball $K-1$ is a variety of cauliflower resistant to Black rot.
$(d)$ Pusa Swarnim is a variety of Brassica (mustard) resistant to White rust.
Therefore, the correct matching is $a-4, b-3, c-2, d-1$.

(D) $IARI$ stands for Indian Agricultural Research Institute. It is a premier national institute for agricultural research,education,and extension in India,located in New Delhi.

(C) Traditional hybridization methods involve crossing two organisms to combine their desirable traits.
However,a major limitation of this technique is that it is not precise.
During the process of sexual reproduction,the entire genome of the parents is involved,which leads to the transfer and multiplication of both desired and undesirable genes into the progeny.
This makes it difficult to isolate only the beneficial traits without including unwanted genetic material.
Modern biotechnology,such as recombinant $DNA$ technology,overcomes this by allowing for the precise selection and transfer of specific genes.

(C) Intergeneric hybridisation involves crossing plants that belong to different genera but the same family.
Triticale is the first man-made cereal crop,which was developed by crossing wheat ($Triticum$ species) and rye ($Secale$ species).
Since wheat and rye belong to two different genera,this process is known as intergeneric hybridisation.
Therefore,the correct option is $C$.

(A) $Hybrid$ $vigour$ is also referred to as $Heterosis$.
It describes the phenomenon where the hybrid offspring exhibit superior qualities,such as increased growth rate,yield,and fertility,compared to their parents.

(C) Germplasm is the sum total of all the alleles of the genes present in a crop and its related species.
The entire collection of plants or seeds having all the diverse alleles for all genes in a given crop is called a germplasm collection.
$A$ good germplasm collection is essential for a successful plant breeding program.

(C) Hybridization is the process of crossing two genetically different individuals to combine their desirable traits in the progeny.
This process is widely used in plant and animal breeding to create genetic variation and develop new,improved varieties or breeds.
Domestication refers to the process of taming an animal or cultivating a plant for human use.
Incubation refers to the process of keeping eggs at a suitable temperature for development.
Mutation refers to a sudden change in the genetic material of an organism.

(C) The International Rice Research Institute $(IRRI)$ is located in Los Baños,near Manila,Philippines.
It is a global research organization dedicated to reducing poverty and hunger through rice science.
In contrast,the Indian Institute of Rice Research $(IIRR)$ is situated in Hyderabad,India,while the National Rice Research Institute $(NRRI)$ is located in Cuttack,India.

(C) High-yielding and disease-resistant wheat varieties were introduced in India in $1963$.
Examples of these varieties include Sonalika and Kalyan Sona,which were developed to improve food production in the country.

(B) Semi-dwarf wheat was developed at the International Centre for Wheat and Maize Improvement in Mexico by Dr. Norman $E$. Borlaug.
This development was a key component of the Green Revolution,which significantly increased wheat production globally.
Semi-dwarf rice varieties were introduced in India in $1966$. These semi-dwarf varieties of rice were developed from $IR-8$ and Taichung Native-$1$.

(A) The correct answer is Norman $E$ Borlaug.
In $1963$,the significant increase in global wheat production was primarily due to the introduction of semi-dwarf varieties of wheat.
These semi-dwarf wheat varieties were developed by Norman $E$. Borlaug at the International Centre for Wheat and Maize Improvement in Mexico.
Similarly,semi-dwarf rice varieties were developed from $IR-8$ (developed at the International Rice Research Institute,Philippines) and Taichung Native-$1$ (developed in Taiwan).

(C) The dwarf rice variety known as Taichung Native-$1$ ($TN$-$1$) was introduced to India from Taiwan. It was one of the first high-yielding dwarf varieties of rice that played a significant role in the Green Revolution in India.

(A) Genetic variability is considered the root of any breeding program.
Plant breeding programs rely on the presence of genetic variation within a population.
This pre-existing genetic variability is collected from wild varieties,wild species,and wild relatives of the cultivated crop species to serve as the foundation for selecting desirable traits.

(C) Modern bread wheat, $Triticum \text{ } aestivum$, is a hexaploid species $(2n = 6x = 42)$.
It originated from the hybridization of $Triticum \text{ } turgidum$ (tetraploid, $2n = 4x = 28$) and $Aegilops \text{ } tauschii$ (also known as $Triticum \text{ } squarrosa$, diploid, $2n = 2x = 14$).
$Triticum \text{ } aestivum$ is the most widely cultivated wheat species globally and is the primary source of modern wheat varieties.

(B) Germplasm collections are essential for plant breeding programs and are usually maintained at a low temperature to preserve viability.
These collections are typically stored in the form of seeds.
The stored seeds are grown periodically in the field to obtain fresh seeds because seed germination capacity decreases over time due to storage.

(A) The semi-dwarf varieties of rice were developed from $IR-8$ and $Taichung$ $Native-1$.
These varieties were introduced in India in $1966$ and were responsible for the Green Revolution in rice production.
$Jaya$ is a variety derived from these,while $Sonalika$ is a semi-dwarf variety of wheat.

(C) The wheat revolution in India during the $1960s$ was primarily driven by the introduction of semi-dwarf wheat varieties.
In $1963$,$ICAR$ (Indian Council of Agricultural Research) introduced high-yielding dwarf wheat varieties developed by Norman Borlaug at $CIMMYT$ (International Maize and Wheat Improvement Center).
These varieties utilized the $Norin-10$ gene,which is responsible for reducing plant height (dwarfing).
By reducing the height,the plants became more resistant to lodging (falling over) and could support heavier grain heads,significantly increasing the yield.

(A) Mutation breeding is the process of developing new plant varieties by artificially inducing mutations using chemical mutagens or physical radiation.
Chemical mutagens include substances like aniline,nitrous acid,and mustard gas.
While alcohol is not a standard mutagen used in breeding,aniline is a well-known chemical mutagen used in this process.
Therefore,among the given options,aniline is the correct chemical used for inducing mutations.

(A) Crop improvement is a systematic process aimed at enhancing the quality,yield,and resistance of plants to various biotic and abiotic stresses.
This process is not achieved by a single method but by a judicious combination of several techniques.
$1$. Selection: Choosing plants with desirable traits from a population.
$2$. Introduction: Bringing plants from one geographical area to another where they were not previously grown.
$3$. Hybridisation: Crossing two genetically different individuals to produce offspring with desirable combinations of traits.
Therefore,the most comprehensive and effective approach for crop improvement involves the integration of selection,introduction,and hybridisation.