不同水分条件下AM真菌对福鼎大白茶生长和茶叶品质的影响

为研究不同水分条件下丛枝菌根（Arbuscular mycorrhizal,AM）真菌对茶树生长和茶叶品质的影响,试验以福鼎大白茶（Fuding Dabaicha）为材料,采用温室盆栽法,分别设置正常水分（WW）和干旱胁迫（DS）两个水分条件,研究单接种AM真菌幼套近明球囊霉（Clariodeoglous etunicatum）（+AMF）与不接种（-AMF）处理对福鼎大白茶实生苗叶片数、生物量等生长指标和蔗糖、果糖、儿茶素、氨基酸等品质指标的影响。结果显示,无论水分条件如何,接种AM真菌处理均显著促进了福鼎大白茶实生苗生长,增加了叶片数量和各部分（叶片、茎、根系）生物量,并提高了茶叶品质;与不接种AM真菌（-AMF）相比,茶树叶片蔗糖、葡萄糖、果糖、儿茶素、氨基酸和茶多酚的含量分别增加了7.73%~21.92%、28.49%~53.44%、6.13%~9.59%、18.97%~23.48%、31.29%~39.11%和6.77%~26.32%。接种AM真菌处理在干旱（DS）条件下效果更为显著,干旱抑制了AM真菌对茶苗根系的侵染和茶苗生长,降低了茶叶品质。接种AM真菌能显著缓解这种抑制效应,同时促进茶叶有机物质积累。此外,接种AM真菌还显著上调了干旱胁迫（DS）下茶树叶片谷氨酰胺脱氢酶基因（CsGDH）、谷氨酰胺α-酮戊二酸氨基转移酶基因（CsGOGAT）和3-羟基-3-甲基戊二酰辅酶A还原酶基因（CsHGMR）的表达。研究结果表明,接种AM真菌在不同水分条件,特别是干旱（DS）条件下,可通过显著上调相关基因的表达来促进茶树的生长,改善茶叶品质。

Influences of Arbuscular Myrorrhizal Fungi on Plant Growth and Tea Quality of Fuding Dabaicha Seedlings under Different Water Conditions

In order to evaluate the effect of an arbuscular mycorrhizal (AM) fungi on the plant growth performance and tea quality of FudingDabaicha under different water conditions, Fuding Dabaicha seedlings inoculated with (+AMF) or without AMF (-AMF) Clariodeoglous etunicatum were evaluated in a pot experiment under drought (DS) and well-watered (WW) conditions. Plant growth performance and quality parameter such as leaf number, biomass, contents of sucrose, fructose, catechuic acid, amino acid, etc. were determined. The results showed that under WW and DS conditions, AMF inoculation markedly promoted plant growth and improved the tea quality, in particularly increased leaf numbers, biomass of each part (leaf, stem and root), and the contents of sucrose, glucose, fructose, catechuic acid, amino acids and tea polyphenols were significantly increased by 7.73%-21.92%, 28.49%-53.44%, 6.13%-9.59%, 18.97%-23.48%. 31.29%-39.11% and 6.77%-26.32% in Fuding Dabaicha seedlings compared with non-AMF seedlings, especially under drought stress condition. Meanwhile, drought stress (DS) significantly restrained root AM colonization and the plant growth of Fuding Dabaicha seedlings, and markedly decreased the quality of FudingDabaicha seedlings, whereas, AMF inoculation significantly relieved this inhibitory effect, promoted the accumulation of tea organic matters. In addition, AMF-colonized seedlings presented higher expressions of glutamate dehydrogenase gene (CsGDH), glutamine oxoglutarate aminotransferase gene (CsGOGAT) and 3-hydroxy-3-methylglutaryl coenzyme gene (CsHMGR) under drought stress condition. The results indicated that AMF inoculation could promote plant growth and improve tea quality by means of up-regulation of relevant gene expression in Fuding Dabaicha seedlings under different water conditions, especially under drought stress.