HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Free Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Yang, J. Articles by Zhu, Q. Search for Related Content PubMed Articles by Yang, J. Articles by Zhu, Q. Agricola Articles by Yang, J. Articles by Zhu, Q. Related Collections Rice Crop Growth and Development Crop Physiology & Metabolism

RICE

Carbon Remobilization and Grain Filling in Japonica/Indica Hybrid Rice Subjected to Postanthesis Water Deficits

^a College of Agric., Yangzhou Univ., Yangzhou, Jiangsu, China
^b Dep. of Biol., Hong Kong Baptist Univ., Kowloon Tong, Hong Kong, China

* Corresponding author (jzhang{at}hkbu.edu.hk)

Received for publication January 2, 2001. Poor grain filling, as in unfilled grains, and unused carbohydrate in straws are two major problems in japonica/indica (J/I) hybrid rice (Oryza sativa L.). This study investigated if an early senescence, induced by controlled postanthesis soil drying, could enhance the remobilization of reserved C to the grains, and therefore improve the grain filling. Two J/I hybrids and one indica/indica (I/I) hybrid were field-grown. Three levels of soil water potential (_soil)—well watered (_soil = 0), moderate water deficit (_soil = -0.025 MPa), and severe water deficit (_soil = -0.05 MPa)—were imposed 9 d after anthesis to maturity. As a result of water deficit treatment, chlorophyll concentrations and photosynthetic rates of flag leaves declined more quickly, indicating an enhanced senescence. The remobilized C reserve from the culm and sheath during grain filling was increased by 47 to 61% for the J/I hybrids and 12 to 26% for the I/I hybrid. Partitioning of ¹⁴C from the flag leaves to the grains was increased by 18 to 28%. Active grain-filling period was shortened by 2.7 to 8.7 d, and grain-filling rate increased by 0.14 to 0.36 mg d^-1 grain^-1. Water deficits reduced the grain yield of the I/I hybrid by 2.9 to 16.4% but increased that of the two J/I hybrids by 4.4 to 13.3%. We conclude that if water deficit is properly controlled for J/I, the gain from enhanced remobilization of stored C may outweigh the loss due to shortened photosynthetic duration, leading to a fast grain filling and high grain yield in cases where senescence is unfavorably delayed.

Abbreviations: Chl, chlorophyll • DAA, days after anthesis • I/I, indica/indica • J/I, japonica/indica • MD, moderate water deficit • NSC, nonstructural carbohydrates • PR, photosynthetic rate • SD, severe water deficit • WW, well watered • _soil, soil water potential

This article has been cited by other articles:

				V. O. Sadras and D. B. Egli Seed Size Variation in Grain Crops: Allometric Relationships between Rate and Duration of Seed Growth Crop Sci., March 19, 2008; 48(2): 408 - 416. [Abstract] [Full Text] [PDF]

				J.I.L Morison, N.R Baker, P.M Mullineaux, and W.J Davies Improving water use in crop production Phil Trans R Soc B, February 12, 2008; 363(1491): 639 - 658. [Abstract] [Full Text] [PDF]

				D.-L. Yang, R.-L. Jing, X.-P. Chang, and W. Li Identification of Quantitative Trait loci and Environmental Interactions for Accumulation and Remobilization of Water-Soluble Carbohydrates in Wheat (Triticum aestivum L.) Stems Genetics, May 1, 2007; 176(1): 571 - 584. [Abstract] [Full Text] [PDF]