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Doubled haploids in tropical maize: II: . Quantitative genetic parameters for testcross performance

Author:
Prigge, Vanessa, Babu, Raman, Das, Biswanath, Hernández Rodriguez, M., Atlin, Gary N., Melchinger, Albrecht E.
Source:
Euphytica 2012 v.185 no.3 pp. 453-463
ISSN:
0014-2336
Subject:
alleles, corn, doubled haploids, dry matter content, genetic variance, genetic variation, germplasm, grain yield, haploidy, loci, microsatellite repeats, quantitative trait loci, selection response, testcrosses
Abstract:
Single crosses (SC) of elite inbreds and open-pollinated populations (OP) are suitable source germplasm for doubled haploid (DH) line development in hybrid maize breeding, given that they combine a high population mean ([Formula: see text]) for testcross performance with adequate response to selection ([Formula: see text]). This is the first study reporting testcross grain yield (TCGY) and dry matter content (TCDMC) evaluations of 131 DH lines developed from ten tropical source germplasm comprising five OP (OP1–OP5) and five SC (SC1–SC5). Gene diversity (d) and the average number of alleles (a r ) per locus was estimated for DH lines based on 24 simple sequence repeat markers. Analysis across three environments revealed no significant differences between [Formula: see text] of OP- and SC-derived DH lines for TCGY and TCDMC. Significant genetic variance for both traits was only detected among OP-derived DH lines which may be explained by a larger number of segregating quantitative trait loci (QTL) as suggested by higher d and a r values than in SC-derived DH lines. The usefulness criterion ([Formula: see text]) was higher for OP-derived DH lines for TCDMC, but higher for SC-derived DH lines for TCGY. DH lines from OP1, OP2, and OP3 showed high TCGY, suggesting that they may be useful in tropical hybrid breeding. We conclude that tropical OP represent a valuable source of untapped genetic variation that can efficiently be exploited with DH technology for hybrid maize breeding.
Agid:
436432