High temperature enhanced zinc and water content in inflorescences and shoot tips of longan (Dimocarpus longan Lour.)

Recently, global warming induced climate change in several regions of the world, is leading to yield loss in agriculture sectors, especially fruit crops. Subtropical fruit trees are one of the most sensitive species affected by rising temperatures, especially longan (Dimocarpus longan Lour.). Improvements on basic knowledge about increasing temperature effects on water content and zinc in inflorescences and shoot tips improved longan fruit production. Inflorescences and shoot tips of `Poung Tong' longan were collected and the cutting area was dipped in water and carried by plastic bag to prevent water loss before placing into an artificial incubator at 40 degrees C ambient temperature with air circulation for 30 min. The control treated samples were kept at room temperature. Analysis of the zinc content in inflorescences and shoot tips was carried out by precision detection of inductively coupled plasma mass spectrometry (ICP-MS). Findings showed the zinc content was 30.39% above the control treatment in the inflorescences and the zinc content in the shoot tips incubated under the high temperature condition (40 degrees C ambient temperature) was 15.06% above the control treatment. In addition, the water content was also translocated into the inflorescences and the shoot tips when incubated under 40 degrees C. The amount of water increased by 7 and 9% over the control treatment in the inflorescences and the shoot tips, respectively. The changes in water content, within the smaller branches of the inflorescences, scanned by electron microscope (SEM), supports the rapid translocation ability of zinc to accumulated in the inflorescence.