Bai Zhigang, Mao Shuchun, Han Yingchun, Feng Lu, Wang Guoping, Yang Beifang, Zhi Xiaoyu, Fan Zhengyi, Lei Yaping, Du Wenli, Li Yabing
Institute of Cotton Research of Chinese Academy of Agricultural Sciences/State Key Laboratory of Cotton Biology, Anyang, 455000, Henan, China.
PLoS One. 2016 May 26;11(5):e0156335. doi: 10.1371/journal.pone.0156335. eCollection 2016.
Identifying the characteristics of light interception and utilization is of great significance for improving the potential photosynthetic activity of plants. The present research investigates the differences in absorbing and converting photosynthetically active radiation (PAR) among various cotton cultivars. Field experiments were conducted in 2012, 2013 and 2014 in Anyang, Henan, China. Ten cultivars with different maturity and plant architectures were planted at a density of 60,000 plants ha-1 in randomized blocks, with three replicates. The spatial distribution of light in canopy was measured and quantified with a geo-statistical method, according to which the cumulative amount of intercepted radiation was calculated by Simpson 3/8 rules. Finally, light interception was analyzed in association with the biomass accumulation of different cultivars. The key results were: (1) late-maturing varieties with an incompact plant architecture captured more solar radiation throughout the whole growth period than middle varieties with columnar architecture and even more than early varieties with compact architecture, and they produced more biomass; (2) the highest PAR interception ratio and the maximum biomass accumulation rate occurred during the blossoming and boll-forming stage, when leaf area index (LAI) reached its peak; (3) the distribution within the canopy presented a significant spatial heterogeneity, and at late growing stage, the PAR was mainly intercepted by upper canopies in incompact-type plant communities, but was more homogeneous in columnar-type plants; however, the majority of radiation was transmitted through the canopy in compact-type colonies; (4) there was not a consistent variation relationship between the cumulative intercepted PAR (iPAR) and biomass among these cultivars over the three years of the study. Based on these results, we attempted to clarify the distinction in light spatial distribution within different canopies and the patterns of PAR interception in diverse cotton cultivars with different hereditary characters, thereby providing a significant basis for researchers to select cultivars with appropriate growth period and optimal plant architecture for improvement of light interception and utilization.
识别光截获与利用的特征对于提高植物潜在光合活性具有重要意义。本研究调查了不同棉花品种在吸收和转换光合有效辐射（PAR）方面的差异。2012年、2013年和2014年在中国河南安阳进行了田间试验。十个具有不同成熟度和株型的品种以60000株·公顷−1的密度种植在随机区组中，重复三次。采用地统计学方法测量并量化冠层内光的空间分布，并据此通过辛普森3/8法则计算截获辐射的累积量。最后，结合不同品种的生物量积累对光截获进行了分析。关键结果如下：（1）植株结构不紧凑的晚熟品种在整个生育期比柱状结构的中熟品种捕获更多的太阳辐射，甚至比结构紧凑的早熟品种捕获更多的太阳辐射，且它们产生的生物量更多；（2）最高的PAR截获率和最大生物量积累速率出现在开花结铃期，此时叶面积指数（LAI）达到峰值；（3）冠层内的分布呈现出显著的空间异质性，在生长后期，PAR主要被不紧凑型植物群落的上部冠层截获，但在柱状型植物中分布更为均匀；然而，在紧凑型群体中，大部分辐射透过冠层；（4）在本研究的三年中，这些品种的累积截获PAR（iPAR）与生物量之间不存在一致的变化关系。基于这些结果，我们试图阐明不同冠层内光空间分布的差异以及不同遗传特性的棉花品种PAR截获模式，从而为研究人员选择生育期适宜、株型最优的品种以改善光截获与利用提供重要依据。
