Half-sib Progeny Testing and Superior Family Selection of Guangxi Red-Heart Chinese Fir

This study analyzed the genetic variation patterns of growth traits in 10-year-old Guangxi Red-heart Chinese fir half-sib families, aiming to screen fast-growing, high-quality superior families to provide germplasm resources for genetic improvement of Guangxi Red-heart Chinese fir. Using 34 half-sib families of Guangxi Red-heart Chinese fir collected from Guangxi as test materials, tree height, diameter at breast height (DBH), timber volume, and basic wood density were measured. Mixed linear models were employed to estimate genetic parameters, and best linear unbiased prediction (BLUP) was used to calculate breeding values, and superior families were selected based on timber volume, which is a core economic trait.The results showed that there were extremely significant differences in growth traits among families(P< 0.01), and the coefficient of variation of mean volume of the family with the highest volume reached 60.06%, indicating that Guangxi red-heart Chinese fir has considerable potential for genetic improvement.Five superior families—Hong 32, Hong 9, Hong 23, Hong 22, and Hong 10—were identified. Their average volume was 0.0806 m³, which was 15.97% higher than the average of the whole population, with an average genetic gain of 9.24%. In addition, the basic wood density of these superior families was higher than the population average. The superior families selected in this study integrate growth performance and wood quality advantages, providing core germplasm support for the construction of seed orchards and the development of high-generation breeding programs of Guangxi red-heart Chinese fir.