Hybrid wheat: quantitative genetic parameters and consequences for the design of breeding programs

Abstract

Commercial heterosis for grain yield is present in hybrid wheat but long-term competiveness of hybrid versus line breeding depends on the development of heterotic groups to improve hybrid prediction. Detailed knowledge of the amount of heterosis and quantitative genetic parameters are of paramount importance to assess the potential of hybrid breeding. Our objectives were to (1) examine the extent of midparent, better-parent and commercial heterosis in a vast population of 1,604 wheat (Triticum aestivum L.) hybrids and their parental elite inbred lines and (2) discuss the consequences of relevant quantitative parameters for the design of hybrid wheat breeding programs. Fifteen male lines were crossed in a factorial mating design with 120 female lines, resulting in 1,604 of the 1,800 potential single-cross hybrid combinations. The hybrids, their parents, and ten commercial wheat varieties were evaluated in multi-location field experiments for grain yield, plant height, heading time and susceptibility to frost, lodging, septoria tritici blotch, yellow rust, leaf rust, and powdery mildew at up to five locations. We observed that hybrids were superior to the mean of their parents for grain yield (10.7 %) and susceptibility to frost (-7.2 %), leaf rust (-8.4 %) and septoria tritici blotch (-9.3 %). Moreover, 69 hybrids significantly (P < 0.05) outyielded the best commercial inbred line variety underlining the potential of hybrid wheat breeding. The estimated quantitative genetic parameters suggest that the establishment of reciprocal recurrent selection programs is pivotal for a successful long-term hybrid wheat breeding.

Genome-based establishment of a high-yielding heterotic pattern for hybrid wheat breeding

“…Our study is based on 135 advanced elite winter wheat lines (SI Appendix, Table S1), which reflect a broad range of diversity present in Central Europe (37). The lines were grouped into a female pool and a male pool according to pollination capability, plant height, and flowering time.…”

“…For 1,604 1 2 1 2 2 3 3 3 2 2 3 3 4 3 3 3 ΔVC,% 95 92 77 74 55 32 45 46 47 42 41 43 39 41 26 25 35 32 of the potential 1,800 single-cross hybrids, a sufficient amount of seeds was harvested for intensive field trials. Details of hybrid seed production have been published elsewhere (37). We added eight commercial lines and two commercial hybrid varieties (quality class E: Genius; quality class A: As de Coeur (hybrid variety), JB Asano, Julius, Tuerkis; quality class B: Colonia, Hystar (hybrid variety), Kredo, Tobak; quality class C: Tabasco) reflecting the current yield performance in Germany.…”

Bridging the gap between marker-assisted and genomic selection of heading time and plant height in hybrid wheat

“…The environments were Böhnshausen (latitude 51151 0 N, longitude 10157 0 E, 146 m above sea level (asl), sandy loam soil texture), Hadmersleben (latitude 51159 0 N, longitude 11118 0 E, 88 m asl, silt loam soil texture), Harzhof (latitude 54124 0 N, longitude 9151 0 E, 25 m asl, sandy loam soil texture) and Hohenheim (latitude 48142 0 N, longitude 9112 0 E, 390 m asl, sandy loam soil texture). The experimental designs were partially replicated a-designs (Williams et al, 2011), where all parents, checks as well as 29% of the hybrids were used in both replications (for details, see Longin et al, 2013). Sowing density ranged from 230 to 290 seeds per m 2 and plot size ranged from 7.5 to 9.7 m 2 .…”

Review on Impact of Plant Breeding in Crop Improvement, Ethiopia

“…The current findings coupled with technological developments in crop genomics and genetics set the stage for plant breeding in which herbivore induced defenses can be used to provide better crop resistance against insect attack (Tamiru et al, 2015) Wheat: Hybrids often display increased yield, enhanced yield stability, and improved abiotic and biotic stress resistance that result from heterosis (hybrid vigor) (Schnable and Springer, 2013). Recent large-scale phenotyping involving extensive collections of inbred lines and hybrids revealed that hybrids were superior to the mean of their parents for grain yield, susceptibility to frost, leaf rust, and Septoria tritici blotch (Gowda et al, 2012;Longin et al, 2013). Consistently higher grain yield stability for wheat hybrids compared with lines was observed in multiplication field trials (Muhleisen et al, 2014).…”