Temperature effects on self incompatibility in Lilium longiflorum.

Area of Science:

• Plant reproductive biology
• Horticultural science
• Plant physiology

Background:

• Plant breeding relies on understanding pollination mechanisms.
• Lilium longiflorum (Easter lily) exhibits self-incompatibility, a genetic mechanism preventing self-fertilization.
• Controlling pollination is crucial for hybrid development and seed production in lilies.

Purpose of the Study:

• To investigate the effect of short heat treatments on the pistil of Lilium longiflorum.
• To determine if heat stress can modulate self-incompatibility and compatibility in lily pollination.
• To identify temperature thresholds for differentiating compatible and incompatible pollen tube growth.

Main Methods:

• Detached pistils of Lilium longiflorum 'Aral No. 5' were submerged in 50°C water for varying durations (0-7 minutes).
• Pistils were then subjected to compatible and incompatible pollination.
• Pollen tube length was measured after 48 hours incubation at 23.5°C to assess pollination success.

Main Results:

• A 1-2 minute heat submersion eliminated self-incompatibility, allowing incompatible pollen to grow.
• A 4-5 minute heat submersion removed compatibility, inhibiting compatible pollen tube growth.
• A distinct temperature window (15-30°C) was identified for differentiating compatible and incompatible pollen tube growth.

Conclusions:

• Short-term heat treatments can effectively manipulate the self-incompatibility system in Lilium longiflorum.
• This method offers a potential tool for controlled pollination and breeding in lilies.
• Understanding temperature-dependent pollen tube growth is key to optimizing heat-based pollination control.