摘要
该研究采用自制循环营养液系统,设置循环营养液且悬根长度为0cm(T1)、静止营养液且初始悬根长度为0cm(T2)、循环营养液且悬根长度为2cm(T3)3个处理,通过测量营养液的溶解氧、pH、EC值,根系与叶片的形态学指标和生理指标,以及根系显微结构观察,以明晰根际氧环境在水培尖叶莴苣中的作用机理。结果表明:(1)尖叶莴苣幼苗的根际氧环境以T3处理最优,T2处理次之,T1处理最差,但它们营养液的pH和离子总量差异不大。(2)各处理根系和叶片的长势均表现为T3>T2>T1;其根系长度、根系表面积、根系体积、平均直径、根尖数、叶片表面积和叶片体积,以及植株茎粗、株高、根干重、地上部干重、壮苗指数、根冠比均以T3处理最大,但T3与T2间均无显著差异,而两者均显著大于T1处理,此时T3处理的壮苗指数和根冠比分别比T1显著增加了38.8%和13.4%。(3)尖叶莴苣根系维管束以及木质部的面积大小均表现为T3>T2>T1。(4)T1处理根系SOD、POD活性均高于相应的T2和T3处理,CAT活性和MDA含量均显著高于T3处理;T1处理叶片叶绿素和4种有机酸含量基本低于T2和T3,柠檬酸及琥珀酸含量以T2最大,苹果酸及丙二酸含量以T3最大。研究发现,根际低氧胁迫对水培尖叶莴苣幼苗生长、生理和品质特性均有明显抑制作用,且空气中的氧气相对于营养液中的氧气抑制作用更明显;在水培尖叶莴苣生产上设置适宜的悬根长度,可增加根系与空气接触面积,从而增加根际氧供给,解决水气矛盾,提升尖叶莴苣的产量与品质。
The self-made circulating nutrient solution system was used to set the circulating nutrient solution with a hanging root length of 0 cm(T 1),a static nutrient solution and an initial hanging root length of 0 cm(T 2),a circulating nutrient solution and a hanging root length of 2 cm(T 3).With these three treatments,we measured the dissolved oxygen,pH,EC value of nutrient solution,root and leaf morphological and physiological indicators,and root microstructure observation,to clarify the role of rhizosphere oxygen environment in hydroponic lettuce mechanism.The results showed that:(1)the rhizosphere oxygen environment of the lettuce was the best T 3 treatment,the T 2 treatment was the second,and the T 1 treatment was the worst.The pH of the nutrient solution and the total amount of ions were not much different.(2)The growth of roots and leaves of each treatment showed T 3>T 2>T 1;the root length,root surface area,root volume,average diameter,number of root tips,leaf surface area and leaf volume,and plant stem diameter and plant height,dry weight of the roots,the dry weight of the shoots,the seedling index and the root-shoot ratio were the highest in T 3 treatment,but there was no significant difference between T 3 and T 2,and both were significantly larger than those of T 1 treatment.The root-to-crown ratio was significantly increased by 38.8%and 13.4%,respectively,compared to T 1.(3)The area of vascular bundles and xylem of root lettuce showed T 3>T 2>T 1.(4)The activities of SOD and POD activities in T 1 treatment were higher than those in T 2 and T 3 treatments.The CAT activity and MDA content were significantly higher than that of T 3 treatment.The chlorophyll and four organic acids in T 1 treatment were lower than that of T 2 and T 3.The content of acid and succinic acid is the largest with T 2,and the content of malic acid and malonic acid is the largest with T 3.It was found that rhizosphere hypoxia stress significantly inhibited the growth,physiology and quality of hydroponic lettuce,and the oxygen in the air was more effective than the oxygen in the nutrient solution.Setting the appropriate length of the roots of the lettuce can increase the contact area between the roots and the air,thereby increasing the supply of rhizosphere oxygen,solving the water-gas contradiction,and improving the yield and quality of lettuce.
作者
尚春雨
严逸男
陈露
许茹
林义章
邵贵荣
钟凤林
SHANG Chunyu;YAN Yinan;CHEN Lu;XU Ru;LIN Yizhang;SHAO Guirong;ZHONG Fenglin(College of Horticulture,Fujian Agriculture and Forestry University,Fuzhou 350002,China;Fujian Jinpin Agricultural Technology Co.,LTD.Fuzhou 350000,China)
出处
《西北植物学报》
CAS
CSCD
北大核心
2018年第10期1895-1904,共10页
Acta Botanica Boreali-Occidentalia Sinica
基金
福建省高等学校新世纪优秀人才支持计划(KLa17011A)
福州市科技项目
设施蔬菜种业创新与服务平台(2017-PT-113)
福建省科技重大专项专题(2018NZ0002-2)
关键词
水培
尖叶莴苣
根际氧环境
生长
生理
品质
hydroponic
tip lettuce
rhizosphere oxygen environment
growth
physiology
quality
作者简介
尚春雨(1994-),男,在读硕士研究生,主要从事蔬菜生理生态研究。E-mail:1577725129@qq.com;通信作者:钟凤林,副教授,硕士生导师,主要从事设施植物遗传资源与生物技术、蔬菜生理生态和蔬菜资源与产业化研究。E-mail:zhong591@fafu.edu.cn。
