Identification of a Natural Hybrid between Castanopsis sclerophylla and Castanopsis tibetana (Fagaceae) Based on Chloroplast and Nuclear DNA Sequences

Abstract

Castanopsis × kuchugouzhui Huang et Y. T. Chang was recorded in Flora Reipublicae Popularis Sinicae (FRPS) as a hybrid species on Yuelushan mountain, but it is treated as a hybrid between Castanopsis sclerophylla (Lindl.) Schott. and Castanopsis tibetana Hance in Flora of China. After a thorough investigation on Yuelushan mountain, we found a population of C. sclerophylla and one individual of C. × kuchugouzhui, but no living individual of C. tibetana. We collected C. × kuchugouzhui, and we sampled 42 individuals of C. sclerophylla from Yuelushan and Xiushui and 43 individuals of C. tibetana from Liangyeshan and Xiushui. We used chloroplast DNA sequences and 29 nuclear microsatellite markers to investigate if C. × kuchugouzhui is a natural hybrid between C. sclerophylla and C. tibetana. The chloroplast haplotype analysis showed that C. × kuchugouzhui shared haplotype H2 with C. sclerophylla on Yuelushan. The STRUCTURE analysis identified two distinct genetic pools that corresponded well to C. sclerophylla and C. tibetana, revealing the genetic admixture of C. × kuchugouzhui. Furthermore, the NewHybrids analysis suggested that C. × kuchugouzhui is an F2 hybrid between C. sclerophylla and C. tibetana. Our results confirm that C. × kuchugouzhui recorded in FRPS is a rare hybrid between C. sclerophylla and C. tibetana.

Chromosome‐scale genome assembly of Castanopsis tibetana provides a powerful comparative framework to study the evolution and adaptation of Fagaceae trees

“…Evolutionary biologists are becoming increasing fascinated by the tracking of adaptive genetic changes of Fagaceae species along latitudinal and elevational gradients to understand how evolutionary shifts enhance adaptation and how the adaptive divergence is maintained in the face of gene flow (Leroy et al, 2020). On the one hand, interspecific gene flow may cause difficulties in defining Fagaceae species (Curtu et al, 2007; Zeng et al, 2020). On the other hand, Fagaceae species identity could be generally determined based on differentiation in genomic loci (Kim et al, 2018; Petit et al, 2013).…”

Simulation of Thinning by Integrating Tree Competition and Species Biodiversity for Target Tree-Based Management of Secondary Forests

“…Generally, secondary forests might have lower productivity compared to primary forests. Elsewhere in the world, over the past five decades, increased human interference has led to the destruction of primary forests, which have been replaced by secondary forests [9,10]. Half of the existing secondary forests may have resulted from direct human interference since the 20th century.…”

“…Half of the existing secondary forests may have resulted from direct human interference since the 20th century. Due to the destruction of primary forests worldwide and continuous human interference, secondary forests have garnered considerable attention from researchers worldwide [7,9]. Therefore, secondary forests need to be scientifically managed for their sustainability and high productivity through the development of appropriate management strategies, such as making optimal thinning plans.…”

“…Therefore, secondary forests need to be scientifically managed for their sustainability and high productivity through the development of appropriate management strategies, such as making optimal thinning plans. In recent years, researchers have extensively studied secondary forests based on stand structure, function, role in the forest ecosystem, and management approaches [8][9][10][11]. However, it could be more challenging because of their relatively complex structure and composition, as well as the degradation of secondary forests.…”

Research and Application of Molecular and Phenotypic Data for Tree Biodiversity Evaluation

“…Zeng et al [7] used chloroplast DNA sequences and 29 nuclear microsatellite markers to investigate C. × kuchugouzhui (natural hybrid between C. sclerophylla and C. tibetana) confirming that it is a rare hybrid between C. sclerophylla and C. tibetana.…”