Question

Which one of the following methods is commonly used to maintain the genetic traits of a given plant?
A. By propagating through seed germination
B. By propagating through vegetative multiplication
C. By generating hybrids through intergeneric pollination
D. By treating the seeds with gamma radiation

Answer 1

Hint: The trait of a plant is its phenotypic and genotypic characteristics that are unique to a given plant. In order to maintain or preserve a genetic trait, the plant must be cloned to get an identical copy.

Complete answer:
The genetic trait of a given plant can be maintained by propagation through vegetative multiplication. Vegetative propagation or multiplication is an asexual method of producing new plants by using a fragment of the parent plant. This results in new plants with the same trait. This type of propagation is possible as the meristem tissue in the stems, leaves and roots have undifferentiated cells, which enables a new identical plant to arise from the fragment of the parent plant.

Thus, the genetic traits of a given plant can be maintained (B) by propagating through vegetative multiplication.

Additional information:
When plants produce offspring sexually only the dominant traits are expressed, which is in accordance to ‘law of dominance’. The other methods in the question: seed germination, intergeneric pollination and treatment of seeds with gamma radiation, are all a result of sexual reproduction in plants. So, the plants produced by such methods will not help in maintaining the trait of a plant.

Note:
Though most of the plants can reproduce through vegetative propagation, it is challenging in case of monocotyledons as they lack vascular cambium. Vegetative propagation is advantageous as the favourable trait of a plant can be passed down to the next generation as well. The plants also reach maturity sooner which reduces the cultivation time. However, if the plant is vulnerable to a particular insect or pathogen the entire field will get wiped out as they are genetically similar. Along with this, the crop yield might reduce as there is no genetic diversity among them.