Wankuan Shen

Genotype×environment interactions in sugarcane between China and Australia

Abstract. Sugarcane improvement has traditionally been conducted by nationally focussed breeding programs, with some exchange of elite cultivars among some programs. It has been generally assumed by breeders that genotype × country interactions are large, and therefore selection trial data in one country may be of limited relevance to another. However, no studies quantifying clone × country interactions have been reported to our knowledge. In research reported here, a common set of mostly unselected sugarcane genotypes was evaluated in commercial production environments in Australia and China. Consistent with past studies, genotype × site interaction was an important source of variation within each country. Overall a moderate to high genetic correlation existed between production environments in China and Australia for cane yield and sugar content (0.77 for both traits). This suggests that despite difference in environmental conditions and crop management in production environments between countries, that selection trials in China have some relevance for selecting clones for Australian environments and vice versa. It also supports the hypothesis that regular exchange of selected germplasm from effective breeding programs between countries will have mutual benefits.

Evaluation of BC1 and BC2 from the crossing Erianthus arundinaceus with Saccharum for resistance to sugarcane smut caused by Sporisorium scitamineum

Sugarcane smut disease caused by the fungus Sporisorium scitamineum is one of the important fungal diseases affecting sugarcane yield and sucrose content around the world. Cultivar resistance is the most appropriate control method for this disease. In this study, 37 BC1 lines chosen from the crossing YC96-40 (F1 of Erianthus arundinaceus) × CP84-1198 (commercial sugarcane cultivar) and 42 BC2 lines chosen from the crossing YCE01-116 (BC1 of E. arundinaceus) × Neijiang57-416 (commercial sugarcane cultivar) were evaluated for smut resistance using artificial inoculation. The results showed that of 79 tested BC1 and BC2 lines of E. arundinaceus, 10 (12.7%) were highly to moderately resistant to smut. BC1 of E. arundinaceus had more resistant lines than BC2 of E. arundinaceus. Of the 37 tested BC1 lines of E. arundinaceus, seven (18.9%) were highly to moderately resistant, while three (7.1%) of the 42 tested BC2 lines of E. arundinaceus were highly to moderately resistant to smut. The resistant lines identified in this study could be used as sources of smut resistance in sugarcane breeding programs.