番茄苗期根际加温对其生长及水分吸收的影响

Effects of root zone heating on growth and water consumption of tomato seedlings

[目的]本文旨在明确适宜的番茄根际加温温度,为北方早春玻璃温室中番茄苗期根际温度调控提供理论和方法依据,缓解低温环境对番茄生长的危害。[方法]在玻璃温室高架岩棉栽培条件下,采用控温加热带对番茄根际进行加温,并设置3个处理即根际不加温(CK)、根际加温至20℃(T20)、根际加温至25℃(T25),研究不同根际加温条件对早春苗期番茄生长、光合、干物质积累和水分吸收等的影响。[结果]根际加温可显著促进番茄株高、茎粗、叶片数的增加,不同时期处理T20比CK株高提高13.6%~17.0%,茎粗提高10.3%~14.3%,叶片数增加3.4%~12.5%;处理T25比CK株高提高7.2%~9.7%,茎粗提高7.7%~15.6%,叶片数增加0%~15.6%;定植后10 d,番茄净光合速率随根际温度呈先升高后降低的趋势,定植后20 d和定植后30 d,番茄净光合速率随根际温度升高而升高;根际加温促进了番茄对水分的吸收,促进了番茄茎、叶干物质积累,提早开花时间,其中处理T20比CK地上部总干重增加79.3%~85.4%,开花提早5 d,处理T25比CK地上部总干重增加29.2%~72.4%,提早开花时间3 d。[结论]T20处理番茄株高和茎粗最大、积累干物质总量最多、开花时间最早,即20℃是早春苗期番茄较为适宜的根际加温温度。

[Objective]In the northern winter or early spring greenhouse vegetable cultivation,low temperature environments such as late frosts often affect the growth and development of vegetables.Root zone temperature(RZT)is one of the important factors affecting tomato growth,especially in soilless cultivation systems where it is greatly affected by the environment.This study aimed to clarify the appropriate root zone heating temperature for tomato seedlings and provide theoretical and method-ological support for regulating RZT in early spring glass greenhouses in the northern regions,alleviating the damage caused by low temperature to tomato growth.[Methods]Under the conditions of elevated rockwool cultivation in a glass greenhouse,root zone heating was applied to tomatoes using a temperature-controlled heating belt.Three treatments were set:no root zone heat-ing(CK),root zone heating to 20℃(T20),and root zone heating to 25℃(T25).The effects of different root zone heating conditions on the growth,photosynthesis,dry matter accumulation,and water consumption of early spring tomato seedlings were studied.[Results]The results indicated that root zone heating significantly promoted the increase in tomato plant height,stem diameter,and leaf number.Compared with CK treatment,the T20 treatment increased plant height by 13.6%to 17.0%,stem diameter by 10.3%to 14.3%,and leaf number by 3.4%to 12.5%at different stages.The T25 treatment in-creased plant height by 7.2%to 9.7%,stem diameter by 7.7%to 15.6%,and leaf number by 0%to 15.6%compared with CK.Ten days after planting,the net photosynthetic rate of tomatoes increased and then decreased with increasing root zone temperature,while 20 and 30 days after planting,the net photosynthetic rate increased with increasing root zone temperature.Root zone heating promoted water absorption by tomatoes,promoted stem and leaf dry matter accumulation,and accelerated flowering.The T20 treatment increased aboveground dry weight by 79.3%to 85.4%compared with CK and accelerated flow-ering by 5 days.The T25 treatment increased aboveground dry weight by 29.2%to 72.4%and accelerated flowering by 3 days.[Conclusion]The T20 treatment resulted in the greatest plant height and stem diameter,the highest total accumulation of dry matter,and the earliest flowering time,indicating that 20℃is the most suitable root zone heating temperature for early spring tomato seedlings.