Longan (Dimocarpus longan) fruit production and global exports are rapidly expanding. Consumer acceptance of this high value crop requires that fruit arrive in excellent condition. Pericarp browning and fungal diseases are the main postharvest problems for longans. Research was conducted to establish optimum storage temperatures and packaging systems to retain fruit quality of ‘Biew Kiew’ longans. Average respiration rates for longans stored at 20 °C (61.6 mg CO2/kg/h) were about twice the rate as those stored at 10 °C (32.7 mg CO2/kg/h) and triple the rate for those stored at 5 °C (21.1 mg CO2/kg/h). Ethylene rates were below 0.4 μg·kg−1·h−1. Fruit quality and shelf life were greatest when stored at 10 °C. Longans held at 20 °C were unmarketable after 10 d, and fruit stored at 5 °C exhibited chilling injury (CI). After storage at 10 °C, longans packaged in microperforated (MP) bags, clamshell (CL) containers, or Peakfresh® film (PF) had the highest visual quality ratings, lowest disease incidences, and longest shelf life when compared with fruit in Lifespan® film (LS) or fiberboard boxes. The most promising packages (MP, CL, PF) were evaluated further under constant 10 °C or simulated shipping (SS) conditions with fluctuating temperatures (22 °C/10 °C/22 °C). Longans in CL containers had the highest visual quality and lowest disease incidence when stored at 10 °C, but there were no differences among package treatments under SS conditions. Also, sensory ratings were greatest for fruit packed in CL or PF when stored at 10 °C but all sensory scores decreased under SS temperatures. When longans were stored under fluctuating temperatures, aril texture and flavor ratings were highest for CL packages. CL, PF, and MP are suitable packages for longans stored under optimal temperatures. However, for longans stored under SS conditions, sensory quality was highest when packaged in CL containers.
Marisa M. Wall, Kate A. Nishijima, Lisa M. Keith and Mike A. Nagao
Jon Y. Suzuki, Tracie K. Matsumoto, Lisa M. Keith and Roxana Y. Myers
Nuclear and chloroplast genetic markers have been extensively used for plant identification and molecular taxonomy studies. The efficacy of genetic markers to be used as DNA barcodes is under constant evaluation and improvement with identification of new barcodes that provide greater resolution and efficiency of amplification for specific species groups as well as distantly related plants. In this study, chloroplast DNA genetic markers for Anthurium, the largest genus in the Araceae family, were adapted from chloroplast markers previously designed for Lemna minor, a member of the same plant family. Primers for chloroplast region trnH-psbA, previously used for molecular systematic studies in Anthurium, as well as primers for the rpoB, rpoC1, psbK-psbI, matK, rbcL, and atpF-atpH regions, all located within the large single copy sequence in the chloroplast genome, were evaluated and found to efficiently amplify target sequences when using DNA of varied quality and concentration extracted from silica-dried leaves of selected accessioned species of Anthurium. The trnH-psbA, psbK-psbI, and atpF-atpH intergenic region primers were further evaluated using Anthurium species spanning different subgeneric groups. Of the intergenic region primers tested, psbK-psbI primers were the most robust, yielding well-defined amplicons across Anthurium species that were consistent, with exceptions, within sectional groupings. Application of the psbK-psbI region amplicon as a visual marker for surveying sectional relationships in Anthurium is novel and serves as a model for the development of a diagnostic method for genotyping plants and testing for sample integrity from among species or germplasm collections. This work further demonstrates the use of dried plant tissue banks as a genetic reference and information resource to support basic research as well as ornamental plant characterization and improvement.