Comparative analysis of fruit characters and nutritional quality between five blackberry (Rubus L.) hybrid strains and their parents

In order to provide a scientific basis for breeding new blackberry (Rubus L.) cultivars in China, this paper analyzed the indexes of fruit characters and nutritional quality for five primary selected hybrid strains (5-8-2, 6-6-3, 7-7-4, 7-10-2 and 7-10-6) as well as their parent cultivars grown in Nanjing China. The result showed that 6-6-3 had the largest fruit size with average fruit weight of 7.89 g and biggest fruit weight of 14.58 g, and was intermediate compared with that of its parents. Its aggregate fruit with larger seeds contained the largest number of small fruits, which showed significant over-parents heterosis. The fruit size of 7-7-4 and 7-10-2 were the smallest, lower than that of their parents. 5-8-2 had the highest yield, which was 3.37 kg plant‑1. 5-8-2, 6-6-3 and 7-10-6 had higher soluble solids content (SSC) than the others. The total acid content (TAC) of 5-8-2 fruit was the lowest, which was only 1.08%. Thus, 5-8-2 with higher SSC/TAC was sweeter. Besides, the SSC, TAC and SSC/TAC of 6-6-3 showed over-parents heterosis significantly. Our result suggested that the fruit characters and nutritional quality of 5-8-2 and 6-6-3 were better than 7-7-4, 7-10-2 and 7-10-6and also inherited the characteristics of their parents, can be used as germplasm resources for further study.