Genetic Studies on Sugar and Fibre Accumulation Patterns Among Different Types of Energy Canes in Mauritius

This study was conducted to assess the accumulation pattern of sucrose and fibre content among different types of energy canes in Mauritius. Twelve highly selected biomass genotypes with variable sucrose to fibre ratios were commonly planted in two variety trials in RCBDs with three replicates. Five month old samples, starting from pre-harvest season (May) to mid-season harvest (September), were taken from the first ratoon crop in 2011. Broadly, all the genotypes followed the same trend in terms of total dry matter content accumulation, with a sharp rise from May to June (pre-harvest season) and a tendency to flatten thereafter. The trends were highly influenced by sucrose accumulation pattern that showed a drastic rise at the pre-harvest season. Fibre content was generally found to be stable across the whole sampling period and, although it increased linearly and marginally up to September, variety by month interaction was non-significant. The genetic variances, H, and genetic coefficient of variances, GCVs, were lowest for sucrose content in May and highest during the first half of the harvest season (June–September). Spearman’s rank correlations showed that highest changes in rank for sucrose content occurred between May and June. These findings confirmed that sampling for sucrose content would be least effective when taken before the harvest season. Fibre content, on the other hand, showed stable genetic variance and GCV and least rank changes across time. As a result, fibre content can be measured at any time during the pre-harvest to harvest period in 8- to 12-month-old crops. Fibre accumulation that demarcated the different types of varieties occurred before the pre-harvest season and remained stored in the stem. The study also highlighted the complexities in using fresh and dry weight estimates of the cane quality traits.