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Performance of spring wheat lines near-isogenic for the reduced-tillering ‘tin’ trait across a wide range of water-stress environment-types
journal contributionposted on 2023-05-18, 23:33 authored by Carina Moeller, Rebetzke, G
Agronomically-important traits were studied in 19 genetically-diverse sets of spring wheat (Triticum aestivum L.) lines near-isogenic (NILs) for the tiller inhibition gene (tin) in contrasting water-stress environment-types (ETs) in the Australian grainbelt between 2010 and 2014. The combination of NILs and ETs generated a wide range of spike numbers (103 to 885 spikes/m2), grain numbers per m2 (GNO; 1400 to 22800 grains/m2), and grain yields (0.3 to 8.2 t/ha). On average, the presence of tin significantly reduced spike numbers (319 vs. 381 spikes/m2), increased the numbers of grains/spike (30 vs. 27 grains/spike), and thousand grain weight (TGW; 38.4 vs. 36.9 g) at maturity. Variation in final biomass and GNO each explained over 70% of the genotypic variation in grain yield. Differences in anthesis biomass explained 38% of the variation in grain yield. The marginal yield response to increases in GNO was slightly greater in the tin-containing lines while the response to increases in final biomass was greater in the non-tin lines (p ≤ 0.016). The harvest index varied with changes in ET (p < 0.001) only. The interaction between presence/absence of tin and environment-type was significant for grain yield, total biomass, spike number, grains/spike, and GNO. Grain yields were similar between NIL groups in the lower-yielding ETs (mean yield <2 t/ha) whereas non-tin lines were higher-yielding in more favourable ETs (mean yield >2 t/ha). The rate of the response in grain yield, total biomass, spike number, and GNO to changes in environmental conditions from ‘unfavourable’ to ‘favourable’ was significantly greater in the non-tin lines, i.e. tin-containing genotypes were less responsive or plastic. Reduced-tillering plasticity was associated with increased plasticity in numbers of grains/spike and, to a lesser extent, TGW. The tin lines produced more grains/spike in ETs averaging 28 to 33 grains/spike while NIL groups had similar grains/spike in ETs with lower means. A slightly greater marginal yield response to increases in GNO in tin lines indicated that greater plasticity in the number of grains/spike and TGW can compensate for reduced spike numbers. It is concluded that large variability in adaptation exists within the group of tin-containing genotypes providing opportunities for further selection to improve wheat performance in environments yielding less than 2 t/ha. Further work on the analysis of GNO and yield determination in tin wheat should also consider changes in resource utilisation and hence competition between plants as mediated by planting arrangement.
Grains Research & Development Corporation
Publication titleField Crops Research
Department/SchoolTasmanian Institute of Agriculture (TIA)
PublisherElsevier Science BV
Place of publicationNetherlands
Rights statementCopyright 2016 Elsevier B.V.