Objective To analyze the variation patterns and genetic parameters of seed and cone traits in the hybrid progeny of Chenshan red-heart Chinese cunninghamia and Chinese cunninghamia，providing a theoretical reference for parental selection in its hybrid breeding and the establishment of multi-clone seed orchards. Method With four superior clones from the 1.5-generation seed orchard of Chenshan red-heart Chinese fir and two superior clones from Chinese fir provenance seed orchard at the national base in Baiyunshan Forest Farm，Qingyuan District，Ji’an City，Jiangxi Province as parents，controlled pollination was conducted according to a 6×6 complete diallel cross design.Measurements and analyses were conducted on four cone traits （cone length，cone width，cone volume，fresh cone weight） and two seed quality traits （thousand-seed weight，germination rate） for the 36 hybrid combinations. Result Cone traits of Chinese fir are primarily influenced by the maternal parent and the interaction between the paternal and maternal parents，while thousand-seed weight and germination rate are jointly affected by the paternal parent，maternal parent，and their interaction.The results showed that extremely significant differences （P0.001） existed among the 36 hybrid combinations for cone length，cone width，cone volume，fresh cone weight，thousand-seed weight，and germination rate.Extremely significant differences （P0.001） were also observed in the general combining ability （GCA），specific combining ability （SCA），and reciprocal effect （REC） for each trait.Cone traits in the hybrid combinations were predominantly controlled by additive gene effects，supplemented by non-additive gene effects.In contrast，two seed quality traits were primarily governed by non-additive gene effects，with additive gene effects playing a supplementary role.The GCA for cone traits was higher in Chinese cunninghamia than in Chenshan Red-heart Chinese cunninghamia，while the GCA for germination rate was generally greater in Chenshan Red-heart Chinese cunninghamia compared to Chinese cunninghamia.Based on the general combining ability for germination rate，clones H43 and H16 of Chenshan Red-hearted Chinese cunninghamia were selected as superior clones.Based on the GCA，SCA，and REC effect values for seed and cone traits in the hybrid progeny，combinations H43×R4，H43×H21，and H21×H48 were identified as superior hybrid combinations. Conclusion Significant differences were observed in the seed and cone traits among different cross combinations of Chinese cunninghamia in the complete diallel mating design.While self-pollination does not significantly affect the cone traits of Chinesecunninghamia，it leads to a severe decline in germination rate.There are considerable differences in the GCA of different seed and cone traits in Chinese cunninghamia.In the selection of breeding parents for Chinese cunninghamia，it is essential to prioritize hybrid combinations that demonstrate outstanding seed germination rates to improve the germination rate of the offspring.
CHEN et al. (Wed,) studied this question.