1College of Agronomy and Biotechnology , China Agricultural University, Beijing 100193, China. College of Agronomy, Inner Mongolia Agricultural University, Huhhot, Inner Mongolia, 010018, China.
2College of Agronomy and Biotechnology , China Agricultural University, Beijing 100193, China
3Texas AgriLife Research, Amarillo, TX 79106, USA.
4College of Agronomy and Biotechnology , China Agricultural University, Beijing 100193, China.
The remobilization of water soluble carbohydrates (WSC) has an important role
for grain yield. This study investigated the accumulation and remobilization of WSC
in non-leaf organs (chaff, upper stem, and lower stem) and their contribution to grain
yield, under different irrigation levels (rainfed, reduced irrigation, and full irrigation)
and seeding rate treatments (450, 600 and 750 plants m
-2) using two winter wheat
cultivars, Shijiazhuang 8 (SJZ-8) and Lumai 21 (LM-21), in two field experiments.
Results showed that decreasing irrigation and increasing seeding rates increased
WSC accumulation and remobilization, remobilization efficiency, and contribution to
grain yield in non-leaf organs. When the organs are ranked from highest to lowest in
terms of the WSC accumulation amount, remobilization amount, remobilization
efficiency, and contribution to grain yield, they are: the lower stem, the upper stem,
and then the chaff. And between cultivars, these amounts were higher in SJZ-8 than
in LM-21. The total contribution, pre-anthesis contribution, and post-anthesis
contribution of WSC remobilization from all non-leaf organs to grain yield ranged
from 11.7 to 21.5%, 4.8 to 9.4%, and 6.9 to 12.1%, respectively. This increase in
WSC accumulation, remobilization, and contribution to grain yield in non-leaf
organs is an important reason high grain yields can be maintained in water-saving
and optimal high density management systems.