Waseem Hussain, Ne, University of Nebraska-Lincoln, Lincoln, NE, Peter Baenziger, 362D Plant Science Building, University of Nebraska - Lincoln, Lincoln, NE, Mary Guttieri, Hard Winter Wheat Genetics, USDA-ARS, Manhattan, KS, Amanda Easterly, Agronomy & Horticulture, University of Nebraska - Lincoln, Lincoln, NE, Gina Brown-Guedira, Crop and Soil Sciences, USDA-ARS, North Carolina State University, Raleigh, NC, Jesse Poland, Department of Plant Pathology, Kansas State University, Manhattan, KS and Jorge Patricio Venegas, Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, NE
Modification of plant height through introduction of semi-dwarf (Rht) genes in wheat was a key factor in the green revolution. Plant height variation in progenies derived from semi-dwarf wheat lines is very interesting and moves attention to investigate the height variation in progenies derived from semi-dwarf wheat genotypes. In this study a set of 204 RILs derived from crossing ‘Harry’ x ‘Wesley’ semi-dwarf wheat lines containing Rht-B1b gene were used to study and map QTLs responsible for plant height variation in semi-dwarf wheat populations. Results revealed significant differences among genotypes, environments and genotype x environment interactions. Heritability of plant height was high (86.6%) and transgressive segregrants were obtained. A total of 8 QTLs were detected across the five environments on chromosomes 1AL, 3B, 5BL and 7A. QTL Qph.hw.5BL.1 expressed in 3 (High rainfall) and QTL Qph.hw.3B.1 in 2 (Low rainfall) environments. The phenotypic variance explained by identified QTLs ranged from 5.76 to 12.89%. Further, 10 pairs of significant digenetic interactions were identified and interactions across chromosomes occurred mostly in the A and B genome. QTL x environment interactions was significant and phenotypic variance explained by QTL x environment interactions ranged from 2.76 to 0.02%. The present study provides new insights to tailor semi-dwarf plant height. Taller semi-dwarfs under drought and shorter semi-dwarfs under irrigation is desirable.