TITLE:
Allocation of Macronutrients in Roots, Sheaths, and Leaves Determines Salt Tolerance in Rice
AUTHORS:
Thieu Thi Phong Thu, Yasui Hideshi, Yamakawa Takeo
KEYWORDS:
Salt Tolerance, Rice, Macronutrient Content
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.9 No.5,
April
20,
2018
ABSTRACT: To determine useful parameters for salt tolerance in
rice and selection of salt-tolerant varieties, their macronutrient contents in
roots, sheaths, and leaves were evaluated under salt stress condition. A
hydroponic experiment was conducted to evaluate 29 rice varieties for salt
tolerance. The salt stress treatment included an artificial seawater solution
(electrical conductivity of 12 dS·m-1). After a 2-week
period of salt stress, standard evaluation scores (SES) of visual injuries for
salt stress were assessed. In addition, we measured the contents of N, P, K, Na,
Mg, and Ca in roots, sheaths, and leaves. The results showed that differences
in macronutrients in the different plant tissues correlated with rice tolerance
to the salt stress condition. Under the control treatment, salt-tolerant
varieties exhibited low K content in root. Under the salt stress treatment, the
salt-tolerant varieties exhibited low SES, high N content in leaves and sheaths,
low Na content in leaves and sheaths, low Mg content in leaves and sheaths, and
low Ca content in sheaths. The salt-tolerant varieties also exhibited high salt
stress treatment/control treatment (ST/CT) ratios for dry matter in sheaths, N
content in leaves and sheaths, and K content in sheaths, and low Na/K ratios in
leaves and sheaths. Therefore, these parameters might be useful to understand
salt tolerance in rice.