Germplasm conservation at liquid N2 temperature is Cryopreservation.

Explanation:
Cryopreservation is a method used for long-term germplasm conservation at extremely low temperatures, typically using liquid nitrogen (N2) at a temperature of -196°C. It involves the preservation of biological materials, such as seeds, embryos, pollen, or plant tissues, at very low temperatures to maintain their viability and genetic integrity for extended periods.

Advantages of Cryopreservation:
1. Long-term storage: Cryopreservation allows the storage of germplasm for an extended period, ensuring its availability for future use.
2. Genetic stability: The low temperatures used in cryopreservation help in preserving the genetic stability of the stored material, preventing any genetic changes or deterioration.
3. Minimal maintenance: Once properly cryopreserved, the germplasm does not require regular monitoring or maintenance, reducing the cost and effort involved in preservation.
4. Wide range of applications: Cryopreservation can be used for the conservation of various biological materials, including plant seeds, animal embryos, and human tissues, making it a versatile method for preserving genetic resources.

Process of Cryopreservation:
1. Selection of material: The material to be cryopreserved is carefully selected, considering its importance and genetic value.
2. Preparation: The material is prepared by treating it with cryoprotectants, which are chemicals that help protect the cells from damage during the freezing and thawing process.
3. Freezing: The material is gradually cooled to a very low temperature using controlled freezing techniques, such as vitrification or slow cooling, to prevent the formation of ice crystals that can damage the cells.
4. Storage: The frozen material is stored in specialized containers called cryo-tanks or cryo-vessels, which are filled with liquid nitrogen (-196°C) to maintain the low temperature required for long-term preservation.
5. Thawing and revival: When needed, the material can be thawed and revived by carefully warming it to room temperature, ensuring its viability and functionality.

Conclusion:
Cryopreservation is a highly effective method for long-term germplasm conservation at liquid nitrogen temperature. It allows the preservation of genetic resources, ensuring their availability for future research, breeding, and conservation efforts.