A biochar application protects rice pollen from high-temperature stress.

Area of Science:

• Agricultural Science
• Plant Science
• Environmental Science

Background:

• High temperatures pose a significant threat to global rice production by negatively impacting pollen viability.
• Understanding the specific effects of different high-temperature scenarios (day vs. night) on rice pollen is crucial for developing climate-resilient crops.
• Investigating the role of soil amendments like biochar and phosphorus (P) in mitigating heat stress is essential for sustainable agriculture.

Purpose of the Study:

• To investigate the impact of high daytime temperature (HDT) and high nighttime temperature (HNT) on the pollen characteristics of two rice cultivars (IR-64 and Huanghuazhan).
• To evaluate the effectiveness of biochar and phosphorus (P) fertilization, alone and in combination, in mitigating heat-induced damage to rice pollen.
• To compare the heat tolerance of the IR-64 and Huanghuazhan rice cultivars.

Main Methods:

• Controlled growth chamber experiments were conducted using two rice cultivars, IR-64 and Huanghuazhan.
• Plants were subjected to three temperature treatments: ambient temperature (AT), high daytime temperature (HDT), and high nighttime temperature (HNT).
• Fertilization treatments included a control, biochar alone, phosphorus (P) alone, and a combination of biochar + P.

Main Results:

• High temperatures (HDT and HNT) significantly reduced pollen fertility, anther dehiscence, pollen retention, and pollen germination in both rice cultivars, with HNT being more detrimental.
• The Huanghuazhan cultivar exhibited greater tolerance to high temperatures compared to the IR-64 cultivar, showing higher pollen fertility and germination rates.
• Combined application of biochar and phosphorus (biochar + P) significantly enhanced the resistance of rice pollen to heat-induced stress in both cultivars.

Conclusions:

• High nighttime temperatures are particularly damaging to rice pollen viability and reproductive success.
• The Huanghuazhan rice cultivar demonstrates superior resilience to heat stress compared to IR-64.
• Biochar and phosphorus fertilization represent a promising strategy for enhancing rice pollen's tolerance to high-temperature stress, warranting further investigation for broader abiotic stress mitigation in crops.