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

This Article 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 ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (7) Citing Articles via Google Scholar Google Scholar Articles by Zhao, D. L. Articles by Spiertz, J. H. J. Search for Related Content PubMed Articles by Zhao, D. L. Articles by Spiertz, J. H. J. Agricola Articles by Zhao, D. L. Articles by Spiertz, J. H. J. Related Collections Weed Management Rice

CROP BREEDING, GENETICS & CYTOLOGY

Cultivar Weed-Competitiveness in Aerobic Rice: Heritability, Correlated Traits, and the Potential for Indirect Selection in Weed-Free Environments

^a Crop and Weed Ecology, Wageningen Univ., P.O. Box 430, 6700AK Wageningen, The Netherlands
^b Plant Breeding, Genetics and Biotechnology, International Rice Research Institute (IRRI), DAPO Box 7777, Metro Manila, Philippines

^* Corresponding author (gatlin{at}cgiar.org)

Forty rice (Oryza sativa L.) cultivars and breeding lines used in the International Rice Research Institute (IRRI) upland rice breeding program were evaluated in adjacent weed-free and weedy trials in aerobic soil conditions during the wet seasons of 2001, 2002, and 2003. The objectives of this study were to investigate genetic variability in weed suppression and yield and to identify traits that could be used as selection criteria for improved weed competitiveness. Correlations among and heritability (H) of agronomic traits and early vigor were estimated in weedy and weed-free trials. Regression analysis was performed to predict weedy yield and weed biomass. Cultivars differed widely in the growth of weed biomass they permitted (126–296 g m^–2) and in yield under competition (0.5–2.5 Mg ha^–1). Cultivar yield, duration, biomass, harvest index, height, and vegetative vigor under weed-free conditions were closely correlated with the same traits measured under weedy conditions. Weedy yield and weed biomass were both moderately heritable (H = 0.55 and 0.38 for means estimated from single-year, three replicate trial, respectively) and genetically correlated with each other (r = –0.84). Weed-free yield and vigor at two weeks after seeding (WAS) were moderately heritable (H = 0.68 and 0.38 for means estimated from a single-year, three replicate trial, respectively) and were highly genetically correlated with weedy yield (r = 1.00 and 0.88, respectively) and weed biomass (r = –0.89 and –0.67, respectively). Vegetative vigor at two WAS and grain yield measured under weed-free conditions explained a combined 87% of cultivar variation in weedy yield and 40% in weed biomass. Indirect selection on these two traits was predicted to be efficient for improving yield under weed competition and weed-suppressive ability of aerobic rice.

Abbreviations: H, broad-sense heritability • HI, harvest index • IRRI, International Rice Research Institute • ISE, indirect selection efficiency • LAI, leaf area index • WAS, week(s) after seeding

This article has been cited by other articles:

				K. Saito, G. N. Atlin, B. Linquist, K. Phanthaboon, T. Shiraiwa, and T. Horie Performance of Traditional and Improved Upland Rice Cultivars under Nonfertilized and Fertilized Conditions in Northern Laos Crop Sci., November 7, 2007; 47(6): 2473 - 2481. [Abstract] [Full Text] [PDF]

				J. Bernier, A. Kumar, V. Ramaiah, D. Spaner, and G. Atlin A Large-Effect QTL for Grain Yield under Reproductive-Stage Drought Stress in Upland Rice Crop Sci., March 1, 2007; 47(2): 507 - 516. [Abstract] [Full Text] [PDF]