Read the given passage and answer the questions that follow:-
Plant breeders aim to create new and improved varieties by crossing different species, and sometimes even genera, to combine desirable traits. To achieve successful crossbreeding, it is crucial to ensure that only the intended pollen grains are used for pollination, while also protecting the stigma from any unintended contamination. This careful selection and controlled pollination process helps breeders create commercially superior varieties with specific traits.
A farmer grows a hybrid variety of a crop. How would the farmer gain if this hybrid were made into an apomict?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → The progeny would not segregate, so seeds saved from the crop could be sown year after year
Hybrid varieties give high yields, but seeds collected from a hybrid do not keep the hybrid characters, because the characters segregate in the progeny. Farmers therefore have to buy costly hybrid seed every year. Apomixis produces seeds without fertilisation, so an apomictic hybrid passes on its characters unchanged.
Option (1) The progeny would show more variation, so the crop would suit new habitats — Incorrect. Apomixis is a form of asexual reproduction. Its seeds do not bring new variation; they keep the hybrid characters unchanged.
Option (2) The progeny would not segregate, so seeds saved from the crop could be sown year after year — Correct. In an apomictic hybrid there is no segregation of characters in the progeny, so the farmer can keep using the hybrid seed to raise a new crop year after year.
Option (3) The fruits would form without fertilisation, so they would be seedless — Incorrect. Fruit formation without fertilisation is parthenocarpy, and such fruits are seedless. Apomixis forms seeds without fertilisation, which is the point of the question.
Option (4) The flowers would not need emasculation, so the hybrid could be crossed more easily — Incorrect. Emasculation is a step of artificial hybridisation. NCERT gives the gain of an apomictic hybrid as seed that keeps the hybrid characters, not easier crossing.
NCERT Extract:
Apomixis and Polyembryony – “… One of the problems of hybrids is that hybrid seeds have to be produced every year. If the seeds collected from hybrids are sown, the plants in the progeny will segregate and do not maintain hybrid characters. Production of hybrid seeds is costly and hence the cost of hybrid seeds become too expensive for the farmers. If these hybrids are made into apomicts, there is no segregation of characters in the hybrid progeny. Then the farmers can keep on using the hybrid seeds to raise new crop year after year and he does not have to buy hybrid seeds every year.”