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Mutation breeding represents a new method of conventional breeding procedures as they have the advantage of improving the defect without losing agronomic and quality character in agriculture and crop improvement. Mutation means the sudden heritable changes in the genotype or phenotype of an organism. Gene mutations are of considerable importance in plant breeding as they provide essential inputs for evolution as well as for re-combination and selection. It is the only method for improving seedless crops.

(A) Paddy cultivation

(b) Angiosperm roots and fungi

1. Dr. M.S. Swaminathan 

2. C.T. Patel 

3. Dr. B.P. Pal

Azolla is a free-floating water fern that fixes the atmospheric nitrogen in association with nitrogen fixing blue green alga Anabaena azolla. It is used as a bio-fertilizer for wetland rice cultivation and is known to contribute 40 – 60 kg/ha/crop. The agronomic potential of Azolla is quite significant particularly for increasing the yield of rice crop, as it quickly decompose in soil.

(d) Anabaena

China, India, South America, Mediterranean, Mesoamerica and South East Asia.

Azotobacter and Clostridium.

Majority of flowering plants are diploid (2n). The plants which possess more than two sets of chromosome are called polyploids. Polyploidy often exhibit increased hybrid vigour, increased heterozygosity, increase the tolerance to both biotic and abiotic stresses and buffering of deleterious mutations.

Pseudoheterosis – Also termed as luxuriance. Progeny possess superiority over parents in vegetative growth but not in yield and adaptation, usually sterile or poorly fertile.

Steps involved in hybridization are as follows:

1. Selection of Parents: Male and female plants of the desired characters are selected. It should be tested for their homozygosity. 

2. Emasculation: It is a process of removal of anthers to prevent self pollination before anthesis (period of opening of a flower).

3. Bagging: The stigma of the flower is protected against any undesirable pollen grains, by covering it with a bag.

4. Crossing: Transfer of pollen grains from selected male flower to the stigma of the female emasculated flower. 

5. Harvesting seeds and raising plants: The pollination leads to fertilization and finally seed formation takes place. The seeds are grown into new generation which are called hybrid.

1. Advantage: Polyploidy often exhibit hybrid vigour and increased tolerance to biotic and abiotic stresses. 

2. Disadvantage: Polyploidy results in reduced fertility due to meiotic error resulting in seedless varieties.

(a) Beauveria species

(c) Domestication

(b) Intervarietal hybridization

Biofertilizers or microbial innoculants are defined as preparations containing living cells or latent cells of efficient strains of microorganisms that help crop plants uptake of nutrients by their interactions in the rhizosphere when applied through seed or soil.

They are efficient in fixing nitrogen, solubilising phosphate and decomposing cellulose. They are designed to improve the soil fertility, plant growth, and also the number and biological activity of beneficial microorganisms in the soil. They are ecofriendly organic agro inputs and are more efficient and cost effective than chemical fertilizers.

(c) Mutation breeding

Correct Answer is : Anthesis

1. Primary Introduction: Primary introduction – When the introduced variety is well adapted to the new environment without any alternation to the original genotype. 

2. Secondary Introduction: Secondary introduction – When the introduced variety is subjected to selection to isolate a superior variety and hybridized with a local variety to transfer one or a few characters to them.

Emasculation

Correct Answer is: (c) Norin 10

Correct Answer is : (c) Luxuriance

(a) White rust

Indian Agricultural Research Institute (IARI).

(c) intravarietal

Correct Answer is: (c) Wheat

(d) Pusa Komal – Brassica

(a) pure line

(a) William S Gaud

(a) Dr. M. S. Swaminathan

Green manuring helps to increase the content of nitrogen soil and also improves the structure and physical property of soil.

Green manuring is defined as the growing of green manure crops and use of these crops directly in the field by ploughing. One of the main objectives of the green manuring is to increase the content of nitrogen in the soil. Also it helps in improving the structure and physical properties of the soil. The most important green manure crops are Crotalaria juncea, Tephrosia purpurea and Indigofera tinctoria.

1. Cassia fistula 

2. Sesbania grandiflora 

3. Azadirachta indica 

4. Pongamia pinnata

1. The process is referred as bagging in plant hybridization. 

2. It is done after emasculation to protect the contact of the stigma of the flower against any other pollen grain.

Correct Answer is: (c) proteins

(b) A is true R is false

1. Okra: Pusa Sawani and Pusa A-4 varieties of Okra are resistant to shoot and fruit borers. 

2. Rapeseed mustard: Pusa gaurav variety of rapeseed mustard shown

1. Dr. Norman E. Borlaug. 

2. Dr. M.S. Swaminathan.

(b) Saccharum barberi and Saccharum officinarum

1. Heterosis or Hybrid vigour 

2. Vegetative propogation is the best suited measure to maintain the vigourisity of hybrid.

(a) Centres of origin

When chromosome number is doubled by itself in the same plant, is called autopolyploidy. 

Example: A triploid condition in sugarbeets, apples and pear has resulted in the increase in vigour and fruit size, large root size, large leaves, flower, more seeds and sugar content in them. It also resulted in seedless tomato, apple, watermelon and orange.

(a) Mass selection – Morphological characters

In asexually propagated crop, progenies derived from a plant resemble in genetic constitution with the parent plant as they are mitotically divided. Based on their phenotypic appearance, clonal selection is employed to select improved variety from a mixed population (clones). The selected plants are multiplied through vegetative propagation to give rise to a clone. The genotype of a clone remains unchanged for a long period of time.

(c) Both reason and assertion is right.