Université de Montpellier, INRA, LEPSE, Montpellier, France.
CIRAD, UMR AGAP, Montpellier, France.
J Exp Bot. 2019 Apr 29;70(9):2523-2534. doi: 10.1093/jxb/ery309.
Multi-genotype canopies are frequent in phenotyping experiments and are of increasing interest in agriculture. Radiation interception efficiency (RIE) and radiation use efficiency (RUE) have low heritabilities in such canopies. We propose a revised Monteith equation that identifies environmental and genetic components of RIE and RUE. An environmental term, a component of RIE, characterizes the effect of the presence or absence of neighbours on light interception. The ability of a given plant to compete with its neighbours is then identified, which accounts for the genetic variability of RIE of plants having similar leaf areas. This method was used in three experiments in a phenotyping platform with 765 plants of 255 maize hybrids. As expected, the heritability of the environmental term was near zero, whereas that of the competitiveness term increased with phenological stage, resulting in the identification of quantitative trait loci. In the same way, RUE was dissected as an effect of intercepted light and a genetic term. This approach was used for predicting the behaviour of individual genotypes in virtual multi-genotype canopies. A large effect of competitiveness was observed in multi-genotype but not in single-genotype canopies, resulting in a bias for genotype comparisons in breeding fields.
多基因型冠层在表型实验中很常见，并且在农业中越来越受到关注。在这种冠层中，辐射截获效率（RIE）和辐射利用效率（RUE）的遗传力较低。我们提出了一个修正的Monteith 方程，该方程可以识别 RIE 和 RUE 的环境和遗传成分。一个环境项，是 RIE 的一个组成部分，描述了有无邻居存在对光截获的影响。然后确定了给定植物与邻居竞争的能力，这解释了具有相似叶面积的植物的 RIE 的遗传可变性。该方法在一个具有 765 株 255 个玉米杂交种的表型平台上的三个实验中得到了应用。正如预期的那样，环境项的遗传力接近零，而竞争力项的遗传力随着物候期的增加而增加，从而鉴定出了数量性状位点。同样，RUE 被分解为截获光和遗传项的效应。这种方法用于预测单个基因型在虚拟多基因型冠层中的行为。在多基因型冠层中观察到了竞争力的巨大影响，但在单基因型冠层中没有，这导致了在育种田进行基因型比较时存在偏差。
