Pollen performance of pomegranate under high-temperature stress

Abstract

The heat stress (30 °C, 35 °C, 40 °C) response of pollen performance in Punica granatum was analyzed. Pollen germination rate and tube length were significantly inhibited after 35 °C and 40 °C treatment. According to cumulative stress response index values, 40 °C had the most destructive impact. Heat stress caused various abnormalities at tubes, especially at apex and the most common abnormalities were sharp change of elongation direction and swelling. Although dense callose accumulation and increase in apex-localized reactive oxygen species was noticed at the apex after 35 °C and 40 °C temperature treatment, the most harmful temperature was stated as 40 °C.