[Effects of early growth stage shading on rice flag leaf physiological characters and grain growth at grain-filling stage].
In a pot experiment, rice plants were shaded during the period from transplanting to booting, aimed to study the effects of early growth stage shading on the rice growth at grain-filling stage. Comparing with the control, early growth stage shading decreased the tiller number by 26.72%, but increased the flag leaf area and soluble sugar content by 33.86% and 30.23%, respectively. The filled-grain number per panicle, 1000-grain mass, ultimate brown rice mass, and maximum and average grain-filling rates decreased by 8.65%, 4.81%, 9.74%, 20.22%, and 19.13%, and the effective panicle number and grain yield declined by 25.26% and 39.56%, respectively. The peak time of grain-filling rate (Tm) advanced 1.66 days, while the grain-filling time (T99) prolonged 6.80 days. For shading-tolerance variety, its flag leaf Chl a, Chl b, and Chl (a + b) contents at early and mid grain-filling stages, and the protein N and soluble sugar contents and Chl a/b in its flag leaves at grain-filling stage all increased under early growth stage shading, and the ultimate brown rice mass and 1000-grain mass maintained at the similar levels as the control. Consequently, its grain yield reduction rate was lower than that of shading-sensitive variety.
Liu
Qi-hua
QH
Shandong Rice Research Institute, Ji'ning 272177, Shandong, China. lqh197901@163.com
Zhou
Xue-biao
XB
Yang
Lian-qun
LQ
Li
Tian
T
Zhang
Jian-jun
JJ
D000383:Agriculture / Q000379:methods; D002241:Carbohydrates / Q000032:analysis; D002523:Edible Grain / Q000737:chemistry / Q000254:growth & development*; D008027:Light; D012275:Oryza / Q000254:growth & development* / Q000502:physiology*; D018515:Plant Leaves / Q000502:physiology; D010940:Plant Proteins / Q000032:analysis; D013997:Time Factors
D002241:Carbohydrates; D010940:Plant Proteins