Question

Which of the following shows the correct sequence of steps of plant tissue culture?
\[A.\;\;\;\;Sterilisation \to {\text{ }}Hardening \to {\text{ }}Selection\;of\;explant \to {\text{ }}Inoculation \to {\text{ }}Regeneration \to {\text{ }}Plantlet\;transfer\]
\[B.\;\;\;\;Selection\;of\;explant \to {\text{ }}Inoculation \to {\text{ }}Regeneration \to {\text{ }}Sterilisation \to {\text{ }}Hardening \to {\text{ }}Plantlet\;transfer\]
\[C.\;\;\;\;Selection\;of\;explant \to {\text{ }}Sterilisation \to {\text{ }}Inoculation \to {\text{ }}Regeneration \to {\text{ }}Hardening \to {\text{ }}Plantlet\;transfer\]
\[D.\;\;\;\;Hardening \to {\text{ }}Sterilisation \to {\text{ }}Selection\;of\;explant \to {\text{ }}Inoculation \to \to {\text{ }}Regeneration \to {\text{ }}Plantlet\;transfer\]

Answer 1

Hint: Plant tissue culture is a laboratory method of plant breeding that was developed by a German botanist Gottlieb Haberlandt in \[1950\]. This method is based on the property of totipotency of plant cells. Here, parts of a plant are used to generate multiple copies of the plant in a very short time. The process of plant tissue culture involves several steps.

Complete answer:
Option A: The procedure of plant tissue culture starts with the selection of explant. An explant is the piece of tissue from the plant that is going to be cultured. Since option A starts with sterilization as the first step, it is incorrect.
Option A is incorrect.
Option B: After the selection of explant, the tissue taken needs to be sterilized with disinfectants such as sodium hypochlorite, silver nitrate, calcium hypochlorite, bromine water, mercuric chloride and hydrogen peroxide. Since the second step is given as inoculation in option B, it is incorrect.
Option B is incorrect.
Option C: After undergoing sterilization, the explant should be inoculated in the nutrient medium and incubated. This leads to the formation of calluses. After further incubation the plantlet regenerates from the callus. The regenerated plantlet is exposed to hardening and then transferred to the green house or the field.
Option C is correct.
Option D: In the option, hardening is given as the first step in plant tissue culture so it is wrong
Option D is incorrect.

Hence, the correct answer is Option C
\[C.\;\;\;\;Selection\;of\;explant \to {\text{ }}Sterilisation \to {\text{ }}Inoculation \to {\text{ }}Regeneration \to {\text{ }}Hardening \to {\text{ }}Plantlet\;transfer\]

Note:
For a successful plant tissue culture, supplementation of a proper nutrient medium is essential. Some of the commercially used mediums are MS medium, White’s medium and \[B5\] medium. The medium consists of inorganic nutrients like nitrogen, phosphorus, sulphur, calcium, potassium, magnesium, iron, molybdenum, copper, zinc, boron and manganese and organic nutrients like carbon and nitrogen.