Objective The differences in growth of Cinnamomum cassia seedlings from different provenances were studied to screen out the excellent provenances and families.

Method 67 families from 6 provenances were used as research objects to carry out comparative analysis of seedling height and ground diameter growth, the comprehensive evaluation method of multiple traits in seedling stage was carried out by using the method of using the breeding comprehensive evaluation meth, and early selection excellent families was conducted, too.

Result The differences in seedling height and diameter among different provenances and families were significant. The Cenxi provenance grew best, while the Pingnan and Dongxing provenances grew poorly. The potential for seed source selection was relatively large because the heritability of seedling height and diameter at breast height is greater than 0.9 and there is significant variation among different seed sources. 13 superior families with obvious growth advantages were preliminarily selected based on the estimation results of family seedling height, ground diameter and their herit. The average seedling height was 29.05 cm, and the average ground diameter was 4.42 mm, which were 1.31 times and 1.10 times of the population average, respectively. The average genetic gain of seedling height and ground diameter reached 29.41% and 9.12%, respectively. The best of them is the 37th family of the Cenxi provenance, followed by the 17th family of the Nannin provenance. The selected family line was ranked as 37th > 17th > 39th > 38th > 24th > 19th > 32nd >36th > 10th > 16th > 13th > 64th > 23rd through comprehensive evaluation. The correlation analysis showed that the correlation coefficient between seedling height and ground diameter is 0.750, reaching an extremely significant correlation, ground diameter was significantly negatively correlated with latitude, both seedling height and ground diameter were significantly negatively correlated with annual rainfall.

Conclusion In this study, the growth variation characteristics of Cinnamomum cassia families of different provenance in the seedling stage were revealed. A number of families with good growth potential were identified by developing early selection methods. The research results can provide a reference for the screening of high-quality germplasm resources of Cinnamomum cassia and the selection of good varieties.