Abstract: 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.

Key words: arbuscular mycorrhizal fungi, tea, drought stress, growth, quality