Question

Identify the correct pairs from the following.
I)Pusa moti of bajra- Mass selection
II)IR-8 of rice-Clonal selection
III)TMV-3 of groundnut-Pureline selection
IV)Aruna variety of castor-Polyploidy breeding
(a)(I),(II)
(b)(I),(IV)
(c)(II),(III)
(d)(III),(IV)

Answer 1

Hint: The oldest plant breeding methods in which a large number of plants of a similar phenotype (observable characters) are selected and their seeds are mixed to form a new variety. The other method is the selection of the most desirable members of a species having the same genetics, for continued vegetative (plant parts) propagation.

Complete answer:
Mass selection and hybrid breeding methods are used for Pusa moti of bajra while the clonal selection method is used for the plant breeding in the case of IR-8 variety of rice.
Clonal selection involves the utilization of clones which is defined as descendants of the same plant obtained by vegetative propagation. This helps in the selection and propagation (growing) of the best individual clones from a mixed population.

Additional Information: -Purpose of mass selection:
-To improve local plant varieties: It is observed that in local varieties, sometimes there are mixtures of several types which differ in flowering maturity time, disease resistance, plant height, etc. These qualities of poor quality plants must be eliminated to get the uniform performance of the variety.
-To purify the existing pure varieties: Over time, the pure line varieties become variable due to mechanical mixtures, natural hybridization, and mutation. Through mass selection, the purity of the pure line varieties is maintained.
-To produce new varieties from mixed local varieties by increasing the frequency of superior genes in plants.
-The procedure of mass selection: The process involves the selection of a large number of individual plants of superior phenotype, compositing the harvested seeds without progeny-testing, the mixture of seeds is sown in large numbers to raise the next generation. The process of mass selection continues until the desired level of uniformity is achieved.
-Purpose of clonal selection:
-The genetic makeup of the members of clones is the same. So a continued vegetative propagation, the desirable qualities of plants can be maintained for a long time.
-The cones produce may have hybrid vigor and is conserved through asexual reproduction.
-The procedure of clonal selection: The superior plants are selected based on yield, maturity, resistance towards disease, from a mixture of a population of vegetatively propagated crops. The progeny are propagated by asexual reproduction to produce clone varieties.
So, the correct answer is, ‘(I),(II).’

Note: The plant breeding is the intentional manipulation of plant species to create desired genotypes and phenotypes for specific purposes. To achieve this, controlled pollination, genetic engineering, or both, followed by artificial selection of progeny, are employed.