Abstract

Research project on germplasm resources and cultivar development for Longan (Dimocarpus longan Lour.) would be a time-consuming project. Because longan is a fruit tree and having a long period of growth and development before flowering. Therefore, time that used for breeding program will be long, too. This project was firstly planned for 3 years and comprised of 3 subprojects. There are 1) Classification of Longan Germplasm and Breeding Program, 2) Influence of Rootstocks on Growth, Diseases and Drought tolerance of Longan CV. ‘Daw’ and 3) Longan: Names and Origins. All subprojects showed progressive results and hopefully, beneficial enough for the project next year.
 The longan varieties in the field collection was about 20 varieties, however, the varieties that used for RAPD and phytogenic tree was about 25 varieties. The extra samples were collected from other fields, beside the university farm. From the phytogenic tree, the longan varieties in the list were separated in to 3 groups based on size of the protein fragments. However, the group of longan varieties still have to be confirmed with the phenotype that would be collected from the field. For the breeding program by crossing between varieties in our collection, the study started from the beginning such as crossing technique that would be suitable for longan and in this first year of study, we are able to cross several varieties and made several F1-hybrid. However, the technique to identify real hybrid by biotechnology is still under investigation. Germination of longan seed in tissue culture system and methods to induce shoot and root from plant parts were very interesting topic and the research works would have been continued. Methods to short cut vegetative growth of longan seedling were also under investigated and have been concentrated more in future studies.
 The subproject on influence of rootstocks on growth, diseases and drought tolerance of longan was not real advance in the first year study due to the slow growth of the seedling after germination and failure of grafting technique.
 The study on names and origins of the longan varieties was very interesting. Eighteen out of twenty six variety names were clarified for their origin. Therefore, we hope that this annual report would be very interesting and useful for all of us and whoever come across it in the future.

Keywords:  longan breeding program, grouping, name and origin, stock selection