当前位置： SCI文献检索 > ANNALS OF BOTANY期刊下所有文献 > Effect of nitrogen form and root-zone pH on growth and nitrogen uptake of tea (Camellia sinensis) plants.

Effect of nitrogen form and root-zone pH on growth and nitrogen uptake of tea (Camellia sinensis) plants.

Abstract：

BACKGROUND AND AIMS:Tea (Camellia sinensis) is considered to be acid tolerant and prefers ammonium nutrition, but the interaction between root zone acidity and N form is not properly understood. The present study was performed to characterize their interaction with respect to growth and mineral nutrition. METHODS:Tea plants were hydroponically cultured with NH4+, NO3- and NH(4+) + NO3-, at pH 4.0, 5.0 and 6.0, which were maintained by pH stat systems. KEY RESULTS:Plants supplied with NO3- showed yellowish leaves resembling nitrogen deficiency and grew much slower than those receiving NH4+ or NH(4+) + NO3- irrespective of root-zone pH. Absorption of NH4+ was 2- to 3.4-fold faster than NO3- when supplied separately, and 6- to 16-fold faster when supplied simultaneously. Nitrate-grown plants had significantly reduced glutamine synthetase activity, and lower concentrations of total N, free amino acids and glucose in the roots, but higher concentrations of cations and carboxylates (mainly oxalate) than those grown with NH4+ or NH(4+) + NO3-. Biomass production was largest at pH 5.0 regardless of N form, and was drastically reduced by a combination of high root-zone pH and NO3-. Low root-zone pH reduced root growth only in NO(3-)-fed plants. Absorption of N followed a similar pattern as root-zone pH changed, showing highest uptake rates at pH 5.0. The concentrations of total N, free amino acids, sugars and the activity of GS were generally not influenced by pH, whereas the concentrations of cations and carboxylates were generally increased with increasing root-zone pH. CONCLUSIONS:Tea plants are well-adapted to NH(4+)-rich environments by exhibiting a high capacity for NH4+ assimilation in their roots, reflected in strongly increased key enzyme activities and improved carbohydrate status. The poor plant growth with NO3- was largely associated with inefficient absorption of this N source. Decreased growth caused by inappropriate external pH corresponded well with the declining absorption of nitrogen.

journal_name

Ann Bot

journal_title

Annals of botany

authors

Ruan J,Gerendás J,Härdter R,Sattelmacher B

doi

10.1093/aob/mcl258

subject

Has Abstract

pub_date

2007-02-01 00:00:00

pages

301-10

issue

eissn

0305-7364

issn

1095-8290

pii

mcl258

journal_volume

pub_type

杂志文章

在线工具

Effect of nitrogen form and root-zone pH on growth and nitrogen uptake of tea (Camellia sinensis) plants.