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 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 (18) Citing Articles via Google Scholar Google Scholar Articles by Betrán, F. J. Articles by de León, D. G. Search for Related Content PubMed Articles by Betrán, F. J. Articles by de León, D. G. Agricola Articles by Betrán, F. J. Articles by de León, D. G. Related Collections Crop Genetics Plant and Environment Interactions

CROP BREEDING, GENETICS & CYTOLOGY

Genetic Diversity, Specific Combining Ability, and Heterosis in Tropical Maize under Stress and Nonstress Environments

^a Corn Breeding and Genetics Program, Texas A&M University, College Station, TX 77845
^b International Maize and Wheat Improvement Center (CIMMYT), Apdo. Postal 6-641, 06600 México D.F., México
^c Paseo del Atardecer 360, Villas de Irapuato, 36670 Irapuato, México

^* Corresponding author (javier-betran{at}tamu.edu)

Estimation of genetic diversity and distance among tropical maize (Zea mays L.) lines and the correlation between genetic distance (GD) and hybrid performance would determine breeding strategies, classify inbred lines, define heterotic groups, and predict future hybrid performance. The objectives of this study were to estimate (i) heterosis and specific combining ability (SCA) for grain yield under stress and non-stress environments; (ii) genetic diversity for restriction fragment length polymorphisms (RFLPs) within a set of tropical lines; (iii) GD and classify the lines according to their GD; and (iv) correlation between the GD and hybrid performance, heterosis, and SCA. Seventeen lowland, white tropical inbred lines were represented in a diallel study. Inbred lines and hybrids were evaluated in 12 stress and nonstress environments. The expression of heterosis was greater under drought stress and smaller under low N environments than under nonstress environments. A set of DNA markers identifying 81 loci was used to fingerprint the 17 lines. The level of genetic diversity was high, with 4.65 alleles/locus and polymorphism information content (PIC) values ranging from 0.11 to 0.82. Genomic regions with quantitative trait loci (QTL) for drought tolerance previously identified showed lower genetic diversity. Genetic distance based on RFLP marker data classified the inbred lines in accordance with their pedigree. Positive correlation was found between GD and F₁ performance (F₁), SCA, midparent heterosis (MPH) and high-parent heterosis (HPH). Specific combining ability had the strongest correlation with GD. Environment significantly affected the correlations between F₁, SCA, MPH, and HPH, with lower values of GD revealed in the more stressed conditions.

Abbreviations: ASI, anthesis-silking interval • CML, CIMMYT maize line • DT, drought tolerance • GD, genetic distance • HPH, high-parent heterosis • IS, intermediate stress • LP, ‘La Posta Sequía’ • MPH, midparent heterosis • PCA, principal component analyses • PIC, polymorphism information content • QTL, quantitative trail locus(i) • RFLP, restriction fragment length polymorphism • SCA, specific combining ability • SGD, specific genetic distances • SS, Severe stress • TS, ‘Tuxpeño Sequía’ • WW, well watered

This article has been cited by other articles:

				C Welcker, B Boussuge, C Bencivenni, J-M Ribaut, and F Tardieu Are source and sink strengths genetically linked in maize plants subjected to water deficit? A QTL study of the responses of leaf growth and of Anthesis-Silking Interval to water deficit J. Exp. Bot., January 1, 2007; 58(2): 339 - 349. [Abstract] [Full Text] [PDF]

				K. E. D'Andrea, M. E. Otegui, A. G. Cirilo, and G. Eyherabide Genotypic Variability in Morphological and Physiological Traits among Maize Inbred Lines--Nitrogen Responses Crop Sci., April 25, 2006; 46(3): 1266 - 1276. [Abstract] [Full Text] [PDF]

				X. C. Xia, J. C. Reif, A. E. Melchinger, M. Frisch, D. A. Hoisington, D. Beck, K. Pixley, and M. L. Warburton Genetic Diversity among CIMMYT Maize Inbred Lines Investigated with SSR Markers: II. Subtropical, Tropical Midaltitude, and Highland Maize Inbred Lines and their Relationships with Elite U.S. and European Maize Crop Sci., October 27, 2005; 45(6): 2573 - 2582. [Abstract] [Full Text] [PDF]

				M. A. Menz, R. R. Klein, N. C. Unruh, W. L. Rooney, P. E. Klein, and J. E. Mullet Genetic Diversity of Public Inbreds of Sorghum Determined by Mapped AFLP and SSR Markers Crop Sci., July 1, 2004; 44(4): 1236 - 1244. [Abstract] [Full Text] [PDF]

				R. C. Meyer, O. Torjek, M. Becher, and T. Altmann Heterosis of Biomass Production in Arabidopsis. Establishment during Early Development Plant Physiology, April 1, 2004; 134(4): 1813 - 1823. [Abstract] [Full Text] [PDF]