Question

In crop improvement haploids are important because they

• A. require one half of nutrients
• B. are helpful in study of meiosis
• C. give rise to hybrids very quickly
• D. pure lines can be formed quickly

Answer 1

The correct option is D

pure lines can be formed quickly

An individual having the chromosome number found in the gamete of the species is called as haploid. These haploid individuals arise from gametes. In nature, they originate from unfertilized eggs, but in laboratories, it can be developed from anthers as well.

• The haploids are useful for immediate expression of mutations.
• Pure lines can be formed quickly from double-haploids.
• A double haploid genome is formed when haploid cells undergo chromosome doubling. The production of haploids and doubled haploids (DHs) through gametic embryogenesis allows a single-step development of complete homozygous lines from heterozygous parents, shortening the time required to produce homozygous plants in comparison with the conventional breeding methods that employ several generations of selfing.
• Double –haploids are also useful in studies related to inheritance of quantitative traits.
• Using double –haploid technique new varieties have been developed in barley, Brassica, rice, maize, rye, potato, pepper and asparagus.