Abstract:

To study the hereditary law of important characters of Cymbidium and provide references for parents’ selection and new varieties breeding, the traits of crossing F₁ generation from Cym. ‘Gohho No Shinpi’ with Cym. ‘Peace in the World’ were analyzed. The quantitative characters and qualitative indicators of parents and hybrid offspring were observed and statically analyzed. The results indicated that overall plant type of F₁ generation tended towards the higher numerical value of the parent. The peduncle length and number of arrows showed positive heterosis advantage. The average value of inflorescence length and flowers were close to the paternal mean. The average value of flower diameter, petal length, petal width, calyx length, and calyx width were between those of the parents and closer to the paternal mean. Most of flower types were round, with petals resembling lotus petals. The flower color trait showed a relatively wide separation, forming a gradient of fusion from the maternal yellow to the paternal green, along with a small number of red and white colors. The parental petal pattern was solid, but the offspring were separated and appeared red. The flower color and petal pattern were superimposed, which were significantly different from the parents. The base color of the lip was related to the flower color, and the separation rule was the same as the flower color. The overall inheritance of lip spots was from the maternal parent, and the distribution of lip spots combined the characteristics of both parents, with 38.3% being closer to the maternal parent and 15.0% being closer to the paternal parent, while the remaining 46.7% were a fusion of both parents. All lip spot colors showed variation in depth, width, and degree of fusion. The variation coefficients of plant phenotypic traits ranged from 10.34%-18.66%, and the coefficients of flower type-related phenotypic traits ranged from 12.57%-35.62%. In conclusion, the variation of F₁ generation was rich, and the heterosis of plant type and flower arrow morphology showed positive super-parent heterosis. In flower color heredity, lip spot color and distribution were based on female parent and gradually changed to male parent fusion gradient, and the flower type was between parents and tended to male parent. This research could supply reference for directed breeding of certain plant types and floral traits.

Key words: Cymbidium hybridium, hybridization, traits, F₁ generation, genetic performance