| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
USDA-ARS and Dep. of Agronomy, Univ. of Arkansas, P.O. Box 287, Stuttgart, AR 72160
* Corresponding author.
Crop genetic uniformity is today a principal concern of plant breeders, and was the major cause of the southern leaf blight, Helminthosporium maydis Race T , epidemic on corn (Zea mays L.) in 1970. Genetic diversity can be measured, to a degree, by coefficient of parentage (r) measurements based on pedigree analysis. The objectives of this study were to construct four pedigree schematics to represent the rice (Oryza sativa L.) cultivars released in the USA, determine the relative genetic contribution of ancestral lines, and examine the genetic trends, by location, that result from using specific germplasms in cultivar development of rice. An examination of the pedigrees of 140 rice accessions demonstrated that all of the parental germplasm can be traced to 22 plant introductions in the southern Rice Belt (Arkansas, Louisiana, Mississippi, Missouri, and Texas) and 23 plant introductions in the western Rice Belt (California). The genetic base of the southern breeding programs can be traced to 13 parental accessions in Arkansas, 12 in Texas, and 16 in Louisiana. Furthermore, 10 of the 12 and 13 parental accessions in the Texas and Arkansas breeding programs, respectively, are identical and 8 of the 13 and 16 accessions in the Arkansas and Louisiana breeding programs, respectively, are identical. An examination of r showed that among the long-grain cultivars ‘Lebonnet’ and ‘Lemont’ have more than 72% of their genes in common and almost 90% of the genes are common in the medium grain cultivars, ‘Calrose’ and ‘Caloro.’ Furthermore, the r value between locations for long grain cultivars showed that ~24 and ~19% of the genes are common in the Arkansas and Texas and the Arkansas and Louisiana cultivars, respectively. These data show how closely related the current rice cultivars are that have been released in the USA.
Received for publication April 24, 1989.
This article has been cited by other articles:
|
|
 |
|
  G. C. Eizenga, H. A. Agrama, F. N. Lee, W. Yan, and Y. Jia Identifying Novel Resistance Genes in Newly Introduced Blast Resistant Rice Germplasm Crop Sci., July 25, 2006; 46(5): 1870 - 1878. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Lu, M. A. Redus, J. R. Coburn, J. N. Rutger, S. R. McCouch, and T. H. Tai Population Structure and Breeding Patterns of 145 U.S. Rice Cultivars Based on SSR Marker Analysis Crop Sci., January 1, 2005; 45(1): 66 - 76. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. S. C. Smith, D. N. Duvick, O. S. Smith, M. Cooper, and L. Feng Changes in Pedigree Backgrounds of Pioneer Brand Maize Hybrids Widely Grown from 1930 to 1999 Crop Sci., November 1, 2004; 44(6): 1935 - 1946. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Xu, H. Beachell, and S. R. McCouch A Marker-Based Approach to Broadening the Genetic Base of Rice in the USA Crop Sci., November 1, 2004; 44(6): 1947 - 1959. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
X. Zhou, T. E. Carter Jr., Z. Cui, S. Miyazaki, and J. W. Burton Genetic Base of Japanese Soybean Cultivars Released during 1950 to 1988 Crop Sci., November 1, 2000; 40(6): 1794 - 1802. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. A. Gravois and J. L. Bernhardt Heritability and Genotype Environment Interactions for Discolored Rice Kernels Crop Sci., March 1, 2000; 40(2): 314 - 318. [Abstract] [Full Text]
|
|
|
|
|
|
H.F.J. Bligh, N.W. Blackhall, K.J. Edwards, and A.M. McClung Using Amplified Fragment Length Polymorphisms and Simple Sequence Length Polymorphisms to Identify Cultivars of Brown and White Milled Rice Crop Sci., November 1, 1999; 39(6): 1715 - 1721. [Abstract] [Full Text]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| The SCI Journals | Agronomy Journal | Vadose Zone Journal | |||
| Journal of Natural Resources and Life Sciences Education |
Soil Science Society of America Journal | ||||
| Journal of Plant Registrations | Journal of Environmental Quality |
The Plant Genome | |||
