Effect of stock plant etiolation on in vitro phenol exudation during culture establishment of guava (Psidium guajava L.)

摘要

The viable and healthy culture establishment is a pre-requisite for successful micropropagation of any plant species. Culture initiation from stock plants of field grown mature trees for micropropagation is difficult either due to severe contamination or by oxidation of the phenolic compounds released by explants as a result of wounding (Mark and Simpson, 7). The oxidation product of phenolic substance (quinones) cause browning of culture media and explants. The polymerization of these with proteinin plant tissue (Loomis and Battlaile, 6) causes growth inhibition or death of explants in wide range of plant species (Ziv and Halevy, 14; Amin and Jaiswal, 1; Gill and Gill, 4). Various techniques have been adopted in the past to neutralize or avoid the build-up of these substance to toxic levels (Vieitez and Vieitez, 13; Broome and Zimmerman, 3; Pieper and Zimmer, 10). Incorporation of reducing agent and adsorbent into culture medium also minimize oxidative browning (Walkey, 15; McComb, 8; Ziv and Halevy, 14). Therefore, a simple method of partial etiolation of stock plants to minimize phenolic oxidation for increasing the survival of culture during establishment phase was studied.