Evaluation of sugarcane x Saccharum spontaneum progeny for biomass composition and yield components

Saccharum spontaneum L. has contributed important traits to modern sugarcane (S. spp. L.) cultivars such as adaptation to environmental stress and ratooning ability. There is interest in further use of S. spontaneum in sugarcane improvement for sugar or energy-from-biomass production systems. In this study, parents and progeny from 43 biparental crosses between sugarcane and S. spontaneum clones were evaluated in field trials in China and Australia, along with several commercial cultivars. The S. spontaneum clones were from diverse geographic origins in China. Measurements were made on biomass composition (% dry matter, brix and pol in juice and cane, purity, fiber content) and yield components. Moderate to high (>0.7) broad-sense heritabilities and high genetic variances were observed for most traits. About half the total genetic variance was retained as among-family variance for the biomass composition traits, but this proportion was generally <25% for biomass yields. Midparent values in an independent trial predicted biomass composition traits reasonably well (generally, r > 0.6), but less so for cane and biomass yield (0 < r < 0.4). Genetic correlations between performance of families evaluated in different countries were strong, providing preliminary evidence that results in one country could be used for identifying elite families in the other. Strategies for efficient development and selection of elite clones from S. spontaneum are suggested.