光照强度对植物连作障碍的影响研究

李松松 谭霄

摘 要：为探究光照强度对植物连作障碍的影响规律及机理，开展了3季不同光照强度（30、150和300μmol/m2/s）下的本生烟（Nicotiana benthamiana）连续种植试验，测量植物每季的生物量、生长指标、光合色素含量、光合作用参数及土壤有机物含量。结果表明，各光照强度下的本生烟均出现了明显的连作障碍，其中高光强下的连作障碍程度最高。通过土壤有机物分析发现，相比于未种植的初始土壤，连作土壤中的2，4-二叔丁基苯酚含量显著提升，且中高光强下的含量高于低光强。在中高光强刺激下，植物根系分泌的2，4-二叔丁基苯酚等酚酸类化合物含量显著增加并随种植季度累积于土壤，从而影响植物光合作用，抑制植物生长。

关键词：光照强度;连作障碍;根系分泌物;本生烟

中圖分类号  S567.04 文献标识码 A 文章编号 1007-7731（2022）04-0012-05

Abstract： To explore the influence and mechanism of light intensity on plant continuous cropping obstacles， the three seasons of continuous planting experiment of Nicotiana benthamiana under different light intensities （30， 150 and 300μmol/m2/s） was carried out. The biomass， growth indexes， photosynthetic pigment content， photosynthetic parameters and soil organic matter content of plants in each season were measured. The results show that obvious continuous crop obstacles were observed under each light intensity， of which the degree of continuous crop obstacles under high light intensity was the highest. The results of soil organic matter analysis show that the content of 2，4-ditert-butylphenol in the continuous crop soil was significantly increased in comparison with the initial soil without planting. Moreover， the content of 2，4-ditert-butylphenol in soils under medium and high light intensity was higher than that under low light intensity. The light intensity could stimulate the plant root to secrete more phenolic acid compounds such as 2，4-ditert-butylphenol that accumulated in soils with planting seasons， thereby affecting plant photosynthesis and inhibiting plant growth.

Key words： Light intensity; Continuous cropping obstacle; Root exudate; Nicotiana benthamiana

随着我国城镇化比例越来越高，农业人口减少、耕地资源紧张以及气候变化背景下的自然灾害频发等都对我国粮食安全造成了威胁。植物工厂的出现为应对这些挑战提供了新思路，是我国未来农业的发展方向之一。但是我国的植物工厂起步较晚，相应的理论研究和技术储备不足，导致实际生产活动中存在诸多制约植物工厂发展的问题，其中以光照管理和连作障碍较为突出。

光照是影响植物生长最重要的环境因子，它既是植物唯一的能量来源，也是植物工厂调节的重要的环境要素之一[1]。连作障碍是指连续在同一土壤栽培同种植物或其近缘植物而引起植物生长发育异常的情况[2]，其导致作物产量、品质下降，是诸如植物工厂等设施农业生产活动中的常见问题。……