Evaluation of phenotypic adaptability and disaster resistance of Schima superba families after snow disaster

To explore the phenotypic adaptability and resistance mechanism of different Schima superba families after snow disaster, and to provide a theoretical basis for breeding and disaster resistance improvement of S. superba.

Taking 24 S. superba families affected by snow disaster as the research object, 13 phenotypes such as DBH, tree height and crown width and forest damage indexes were measured. The correlation between phenotypic characteristics and disaster resistance of families was comprehensively evaluated by variance analysis, correlation analysis, cluster analysis and principal component analysis.

1) Different families of S. superba showed significant differences in growth traits and crown shape characteristics. The DBH of LQ15, XF02, JO30, JO58 and QY10 families was much higher than the average value of 5.47 cm, showing fast-growing potential. The YX01 family enhanced the survival rate with low tree height (2.8 m). The branch height and natural pruning ability of LX02 and HA02 families were outstanding; 2) The JO16 family improved resource utilization efficiency through canopy expansion, while the YX01 family adopted a strategy of inhibiting canopy expansion to adapt to the rain and snow disaster environment; 3) There were significant differences in the sensitivity of S. superba families to rain and snow disasters. The YX01 family had the highest damage rate and its resistance to mechanical damage was weak, while the LX02 and JO16 families showed strong resistance to snow disasters and were not significantly damaged; 4) Growth traits were significantly correlated with disaster resistance. DBH and tree height were negatively correlated with damage rate, average damage level and damage index (P<0.05). The proportion of branch height, crown volume and crown height were significantly positively correlated with the damage degree of S. superba, reflecting their vulnerability under high stress environment; 5) Principal component analysis (cumulative contribution rate of 92.735%) showed that LX02, JO16, LQ01, JO5 and XF02 families performed best in phenotypic characteristics.

The LX02, JO16, LQ01, JO5 and XF02 families have both growth potential and disaster resistance adaptability, and can be used as priority breeding materials. The YX01 family is not suitable as a breeding material. In the future cultivation of S. superba, reasonable selection and cultivation should be carried out according to the growth potential and disaster resistance of S. superba.