Acquisition of cryotolerance in maize embryos during seed development

Area of Science:

• Plant Science
• Seed Biology
• Cryobiology

Background:

• Cryopreservation and desiccation tolerance are crucial for preserving plant genetic resources.
• Understanding the developmental acquisition of these tolerances in crops like maize is essential for improving seed banking strategies.

Purpose of the Study:

• To investigate the developmental trajectory of desiccation tolerance and cryotolerance in maize embryos.
• To determine the relationship between embryo developmental stage, moisture content, and survival after dehydration and cryopreservation.

Main Methods:

• A desiccation-based cryopreservation protocol was applied to maize embryos at various developmental stages (23-50 days after pollination).
• Survival and emergence rates were assessed after dehydration and post-cryopreservation treatments.
• Correlation between moisture content and tolerance was analyzed in relation to embryo development.

Main Results:

• Desiccation tolerance increased progressively from 23 days after pollination (DAP), peaking at 38 DAP.
• Cryotolerance was absent until 26 DAP, gradually increasing to a maximum at 44 DAP.
• Optimal moisture content for cryopreservation success varied significantly with embryo developmental stage.

Conclusions:

• Desiccation tolerance and cryotolerance in maize embryos are acquired gradually and concurrently during seed development.
• Embryo developmental stage is a critical factor influencing cryopreservation success, particularly concerning optimal moisture content.
• These findings provide insights into optimizing cryopreservation protocols for maize germplasm.