The importance of water-soluble carbohydrates in the theoretical framework for nitrogen dilution in shoot biomass of wheat

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• 作者：M. Hoogmoed ; ^{Marianne.hoogmoed@sa.gov.au" class="auth_mail" title="E-mail the corresponding author} ; V.O. Sadras ^{Victor.sadras@sa.gov.au" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Crop diagnostics ; Nitrogen nutrition index ; Non-structural carbohydates ; Reserve carbohydrates ; Triticum aestivum ; Water stress
• 刊名：Field Crops Research
• 出版年：2016
• 出版时间：July 2016
• 年：2016
• 卷：193
• 期：Complete
• 页码：196-200
• 全文大小：718 K

文摘

Breeding for yield has increased the concentration of reserve water-soluble carbohydrates (WSC) in wheat from dry, low yielding environments of Australia to wet, high-yielding environments of the UK. This generalized increase in WSC can reduce the concentration of nitrogen (N) in shoots and consequently reduce the crop critical N concentration (%N_c: the minimum concentration of N to achieve maximum growth rates). This may cause errors when assessing a crop’s N status using N dilution curves which relate critical N concentration (%N_c) and shoot biomass (W), i.e. %N_c = aW^−b. Inaccurate diagnosis of a crops N status will have negative environmental and economic consequences such as N losses to the environment and yield gaps. Here, we (i) outline the drivers of variation in WSC, (ii) discuss the implications of WSC on wheat N status, (iii) propose an adjustment of the theoretical N dilution framework that makes explicit a WSC compartment, and (iv) provide estimates of the range of error derived from the current two-compartment model.