根际通电栽培对植物工厂生菜生长及叶烧病发生的影响

针对人工光植物工厂内由钙缺乏而引起的叶菜叶烧病频发的问题,以较易发生叶烧病的生菜作为试验材料,采用在生菜根际建立电压为-15kV全天工作的通电系统,使生菜植株带负电,并在地上部生长空间形成正向电场的方法,设置根际通电处理为试验组,无通电处理为对照组,探究根际通电栽培对生菜生长、钙离子吸收以及叶烧病发生的影响。结果表明:1)对照组的生菜植株在第13天发生叶烧病现象,而试验组的生菜则在第15天出现叶烧病,且在第20天叶烧病的发生率降低了46.9%;2)移栽第20天,与对照组相比,试验组生菜植株的地上部和地下部鲜质量分别提高了6.3%和30.9%,干质量分别提高了17.2%和22.4%;3)移栽第10天,试验组生菜的根系活力和Ca~(2+)吸收能力分别较对照组提高了133.3%和108.9%;4)移栽第20天,试验组生菜的气孔导度、蒸腾速率和胞间二氧化碳浓度分别较对照组提高了46.2%、49.0%和5.2%,生菜光合产物的积累也得到提高。综上,在植物工厂综合环控条件下,根际通电栽培能显著改善生菜的生长发育,并能有效地减缓叶烧病的发生。

Effects of rhizosphere electrified cultivation on lettuce growth and tipburn occurrence in a plant factory

Aiming at the problem of frequent occurrence of lettuce tipburn caused by calcium deficiency in the plant factory under artificial light, a lettuce variety, which is relatively sensitive to tipburn, was chosen as the experimental material. An electric field generation system in the root area with the electric voltage of -15 kV was employed in this experiment. The system was operated for 24 h per day to make the lettuce plant negatively charged and form a positive electric field with the shoot growth space. The rhizosphere electrified treatment was used as the experimental group, and the non electrified treatment was used as control. The effects of rhizosphere electrified cultivation on the growth, Ca²⁺ absorption and tipburn of lettuce were explored. The results showed that: 1)Tipburn occurrence of lettuce plant was observed in the control on day 13, whileit was observed on day 15 in the experimental group. Compared with the control, the ratio of the number of leaves with tipburn to total leaves was reduced by 46. 9% under the experimental group on day 20; 2)Compared with the control, the fresh weight of shoot and root of the experimental group increased by 6. 3% and 30. 9%, and the dry weight increased by 17. 2% and 22. 4% on the 20th day of transplanting; 3)On the 10th day of transplanting, the root activity and Ca²⁺ absorption capacity of the experimental group were increased by 133. 3% and 108. 9% respectively compared with the control; 4)On the 20th day of transplanting, the stomatal conductance, transpiration rate and intercellular carbon dioxide concentration of the experimental group were increased by 46. 2%, 49. 0% and 5. 2%, respectively, and the accumulation of photosynthetic products was also improved. In conclusion, under the comprehensive environmental control conditions of plant factory, the rhizosphere electrified cultivation can significantly improve lettuce plant development and alleviate tipburn occurrence.