Light is one of the most important environmental factors that strongly mediates plant physiological and morphological development. Few studies have investigated the effect of light on perennial fruit crops, which have long generation times and are large in size, that complicates the evaluation of plant responses to light in controlled environments. This study assessed the impact of light intensity on chlorophyll (Chl) variation in 41 kiwifruit cultivars during the growing season, and examined the physiological, morphological and gene expression changes of kiwifruit plantlets in vitro under different light qualities treatments, such as white light, red light (RL), blue light (BL) and a mixture of RL and BL with different ratios. The Chl content in 24.4% of kiwifruit varieties increased continuously with increasing sunlight intensity from April to August; but 34.15% of varieties remained unchanged and 41.5% of varieties decreased in July and August when kiwifruit plants were exposed to maximum solar radiation density and duration. The controlling experiment of light qualities showed that blue light was effective for the induction and accumulation of kiwifruit Chl contents and carbon nitrogen ratio (C/N ratio), as well as the numbers of guard cell plastids, whereas red light induced plant vegetative growth and increased starch and sucrose content in leaves. Furthermore, blue light induced higher expression of key genes for Chl biosynthesis than red light. These results indicate that kiwifruit plants exhibit strong morphological plasticity induced by light, and the development of kiwifruit can be induced by culturing the plants in vitro under a combination of BL and RL.

光是强烈介导植物生理和形态发育的最重要的环境因素之一。很少有研究调查光对多年生水果作物的影响，这些作物的世代时间长且尺寸大，这使得在受控环境中评估植物对光的反应变得复杂。本研究评估了光照强度对 41 个猕猴桃品种在生长季节的叶绿素 (Chl) 变异的影响，并考察了猕猴桃幼苗在体外的生理、形态和基因表达变化。在不同的光质量处理下，如白光、红光（RL）、蓝光（BL）以及不同比例的 RL 和 BL 混合。4-8月，随着日照强度的增加，24.4%的猕猴桃品种的Chl含量不断增加；但在猕猴桃植株暴露于最大太阳辐射密度和持续时间的 7 月和 8 月，34.15% 的品种保持不变，41.5% 的品种减少。光质调控实验表明，蓝光对猕猴桃叶绿素含量和碳氮比（C/N比）以及保卫细胞质体数量的诱导和积累是有效的，而红光对植物营养生长和增加叶片中的淀粉和蔗糖含量。此外，蓝光比红光诱导更高的 Chl 生物合成关键基因的表达。这些结果表明，猕猴桃植株在光诱导下表现出很强的形态可塑性，在 BL 和 RL 的组合下进行体外培养可以诱导猕猴桃的发育。