Damaged sieve tubes are sealed by deposition of

Which of the following plant part is used as a explant to prepare virus free plant ?

To obtain virus ­ free healthy plants from a diseased one by tissue culture technique, which part/parts of the diseased plant will be taken?

Which of the following shows correct chronological order of the events occurring during callus culture?

By tissue culture, indefinite number of plants from a small amount of parental tissue can be obtained. This technique is of great economic importance as