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Forty‐eight Years of Rice Improvement in Texas since the Release of Cultivar Bluebonnet in 1944
Author(s) -
Tabien Rodante E.,
Samonte Stanley Omar PB.,
McClung Anna M.
Publication year - 2008
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci2007.12.0680
Subject(s) - cultivar , biology , oryza sativa , agronomy , grain yield , yield (engineering) , crop , plant breeding , breeding program , horticulture , gene , biochemistry , materials science , metallurgy
Information on the contribution of plant breeding to changes in yields and other agronomic traits is useful for optimizing selection gains; thus, this study aimed to determine the contribution of Texas rice ( Oryza sativa L.) breeding to changes in cultivars released during the 48 yr since the release of ‘Bluebonnet’ in 1944. Twenty‐three cultivars were evaluated in three environments and two N levels. Days to heading, plant height, whole and total milled rice percentages, and grain yield were measured. Significant variation among cultivars was found for all traits evaluated, while N affected all traits except milled rice. There was a linear decrease in days to heading in cultivars released from 1944 to 1992. Plant height decreased at 1.28 and 1.10 cm yr −1 for the 190 and 95 kg ha −1 N levels, respectively, mainly due to the incorporation of the semidwarf gene in many cultivars starting in 1981. Plant heights of recently released cultivars were more stable across N levels and less susceptible to lodging. Although whole and total milled rice percentages increased at 0.06 and 0.03% yr −1 , respectively, environmental factors limited their genetic advances. Grain yield increased at 42.0 and 26.3 kg ha −1 yr −1 under the 190 and 95 kg ha −1 N levels, respectively, demonstrating that newer releases responded well to higher N. These show the remarkable progress in the Texas rice breeding program from 1944 to 1992.