Screening of Superior Provenances and Study on Molecular Mechanisms of Pinus strobus L.

AbstractIn this study, using 10 provenances of P. strobus L. as the experimental materials, their plant height, diameter at breast height (DBH), and crown width were measured, and Illumina NovaSeq 6000 high-throughput sequencing technology was applied to conduct transcriptome sequencing of different provenances on P. strobus L. The growth traits and gene expression patterns of different provenances were analyzed to reveal the molecular mechanism underlying the formation of their growth advantages. The results showed that there were significant differences in tree height, DBH, and timber volume among different provenances (p < 0.05), while there is no significant difference in crown width (p > 0.05). Among the four provenances (2002-2, 2002-3, 2002-6, 2002-8), the plant height and DBH are the largest, and they can be classified as excellect provenances. The differential expression analysis identified 26,212 differentially expressed genes (DEGs, with P_adjust<0.05 & |log₂FC|≥1). The GO and KEGG enrichment analyses indicated that the DEGs of P. strobus L. of well-growth were mainly enriched in metabolic pathways such as galactose metabolism and monoterpene biosynthesis; those of the moderate growth ones focused on stress resistance pathways (e.g., plant-pathogen interaction); while those of the poorly-growth oneswere concentrated in basic amino acid metabolism pathways. Therefore, the growth differences among the P. strobus L. provenances are closely related to the functional differentiation of gene expression. The superior growth-level populations support their growth advantages through efficient metabolic pathways, and the selected excellent provenances are highly compatible with the climatic conditions of the introduction site.