Yunnan Sugarcane Research Institute, Yunnan Academy of Agricultural Sciences, 363 Eastern Linquan Road, Kaiyuan 661600, Yunnan Province, P.R. China.
CSIRO, Australian Tropical Science Innovation Precinct, Private Mail Bag PO, Aitkenvale, QLD 4814, Australia.
J Exp Bot. 2017 Apr 1;68(9):2377-2385. doi: 10.1093/jxb/erx107.
Sugarcane, derived from the hybridization of Saccharum officinarum×Saccharum spontaneum, is a vegetative crop in which the final yield is highly driven by culm biomass production. Cane yield under irrigated or rain-fed conditions could be improved by developing genotypes with leaves that have high intrinsic transpiration efficiency, TEi (CO2 assimilation/stomatal conductance), provided this is not offset by negative impacts from reduced conductance and growth rates. This study was conducted to partition genotypic variation in TEi among a sample of diverse clones from the Chinese collection of sugarcane-related germplasm into that due to variation in stomatal conductance versus that due to variation in photosynthetic capacity. A secondary goal was to define protocols for optimized larger-scale screening of germplasm collections. Genotypic variation in TEi was attributed to significant variation in both stomatal and photosynthetic components. A number of genotypes were found to possess high TEi as a result of high photosynthetic capacity. This trait combination is expected to be of significant breeding value. It was determined that a small number of observations (16) is sufficient for efficiently screening TEi in larger populations of sugarcane genotypes The research methodology and results reported are encouraging in supporting a larger-scale screening and introgression of high transpiration efficiency in sugarcane breeding. However, further research is required to quantify narrow sense heritability as well as the leaf-to-field translational potential of genotypic variation in transpiration efficiency-related traits observed in this study.
甘蔗是由甘蔗野生种和甘蔗栽培种杂交衍生而来的一种营养体作物，其最终产量主要由茎秆生物量决定。在灌溉或雨养条件下，通过开发叶片具有高内在蒸腾效率（CO2 同化/气孔导度）的基因型，可以提高甘蔗产量，但这可能会因导度和生长速率降低而产生负面影响。本研究旨在将中国甘蔗相关种质资源库中多样性克隆样本的内在蒸腾效率（TEi）的基因型变异，分为气孔导度变异和光合能力变异。次要目标是为优化种质资源的大规模筛选制定方案。TEi 的基因型变异归因于气孔和光合成分的显著变化。一些基因型由于具有较高的光合能力而具有较高的 TEi。这种性状组合预计具有重要的育种价值。研究结果表明，在较大的甘蔗基因型群体中，只需进行少量观察（16 次）就可有效地筛选 TEi。所报告的研究方法和结果令人鼓舞，为在甘蔗育种中进行更大规模的蒸腾效率筛选和导入提供了支持。然而，还需要进一步研究，以量化蒸腾效率相关性状的狭义遗传力以及本研究中观察到的基因型变异在叶片到田间的转化潜力。
