This project collected appropriate germplasm and did intergeneric hybridization to create new orchid varieties, such as potted Holcoglossum, Vanda, Rhynchostylis and mini Cattleya, which have a short juvenile period and improved low temperature tolerance. This year completed the collection of a total of 42 orchid varieties, such as Vandastylis, Holcostylis and Cattylea spp. and 65 intergenic hybridizations this year. Some seeds of mature pods have been planted, and 139 intergenic hybrids of seedlings have grown and 42 varieties grew out of flask. After long- day and cold treatment, H. pumilum is orchid flower induced by low temperature. Because of H. pumilum and Holcostylis Pink Yawi stayed at 28/23℃growth chamber, the high temperature treatment in October for one month, the flowering time delayed for more than one month in next late February successfully. In order to understand the incompatibility of intergeneric hybridization, karyotype analysis technology was established and chromosome number analysis of 7 strains was completed. The mini Cattleya collected in this study were intergeneric crossed with large flowers, bright colors, or fragrance Cattley varieties. It is expected that new hybrid progeny with short plants, large flowers with fragrance and pleasant color can be selected.

▲Figure 1. After adjusting the flowering period, the flowering of Holcoglossum pumilum (middle) and its intergeneric hybrids were delayed by more than a month. Presented live at the World Orchid Conference on February 27, 2024.

▲Figure 2. Some hybrids with compact plant size bred in this study. (a) Hybrid1052-1 of (Rlc. Husky Boy 'Michael' x C. Chief White 'May Breeze'); (b) Hybrid 1955-1, (c) Hybrid 1955-5, (d) Hybrid 1955-7, (e) Hybrid 1955-12 of (Rlc. Hsinying Boy'Gypsy' x Ctt. Chief Berry'Berry'); (f) Hybrid 5255-2 of (C. Chief White 'May Breeze' x Ctt. Chief Berry'Berry'); (g) Hybrid 5452-1 of (Lcn. Tzeng-Wen Lace x C. Memoria Robert Strait) x C. Chief White 'May Breeze'; (h) Hybrid 5452-1 of (Lcn. Tzeng-Wen Lace x C. Memoria Robert Strait) x C. violacea; (i) Hybrid 5552-2, (j) Hybrid 5552-5, (k) Hybrid 5552-6 of (Ctt. Chief Berry'Berry' x C. Chief White 'May Breeze'); (l) Hybrid 5555-2, (m) Hybrid 5555-2 of (Ctt. Chief Berry'Berry' x Ctt. Chief Berry'Berry'); (n) Hybrid 6017-1, (o) Hybrid 6017- 3, (p) Hybrid 6017-4 of (C. alaorii x C. walkeriana) x Rth. Petit Patti ‘Lucky’