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Identification and inheritance of gametoclonal variation for quantitative traits in spring wheat
Abstract
Doubled haploid (DH) breeding method is a rapid technique to produce homozygous lines from a segregating population. Gametoclonal variation has been documented in wheat (Triticum aestivum L.) cultivar derived DH lines. Less is understood about the heritability of gametoclonal variation and the presence of gametoclonal variation in DH lines derived from crosses when compared to conventional derived single seed descent (SSD) lines. Gametoclonal variation was identified in Chris DH lines for grain volume weight (GVW) and in Kitt DH lines for grain yield and GVW. When these DH lines were used as parents, F$\sb2$ progeny bulks did not show altered agronomic performance. Additionally, DH lines were crossed with SSD lines and parent-offspring regression of F$\sb4$ lines on F$\sb3$ lines showed significant broad sense heritability for low grain yield (H$\sp2$ = 0.21, heritable gametoclonal variation) and earlier days to heading (H$\sp2$ = 0.33, heritable within cultivar variation). Gametoclonal variation may be present in DH lines derived from Pavon 76 x Chris, but its effects could not be separated from linkage and genotype x environments interactions. Population parameter evaluation showed that grain yield associated genes were repulsion phase linked and genotype x environment interactions influenced GVW distributions. For plant height, DH and SSD populations showed bimodal distributions. Gibberellic acid (GA) insensitive tests confirmed the presence of a single plant height gene. DH lines failed to segregate in the expected 1 short: 1 tall ratio. Thus, gametoclonal selection may have occurred during tissue culture process and resulted in higher frequency of short lines. The previous two research projects assessed gametoclonal variation using anther culture derived DH lines. Gynogenetic (maternal) derived DH's may not have similar gametoclonal variation. Towards this point, factors affecting efficient gynogenetic haploid production were evaluated. Maize pollinated wheat plants were sprayed with either 2,4-D or 2,4-D + GA hormone solutions and higher numbers of embryos and plants were recovered than when pearl millet was used as a pollen source. Fresh pearl millet pollen was superior to pearl millet pollen stored in an ultra-low temperature freezer.
Subject Area
Agronomy|Biostatistics|Plant propagation
Recommended Citation
Oberthur, Laura Elaine, "Identification and inheritance of gametoclonal variation for quantitative traits in spring wheat" (1993). ETD collection for University of Nebraska-Lincoln. AAI9406086.
https://digitalcommons.unl.edu/dissertations/AAI9406086