Tilling for TtBH-1 gene and its hybridization to Turkish durum wheat cultivars kiziltan-91 and Fuatbey-2000


Thesis Type: Doctorate

Institution Of The Thesis: Orta Doğu Teknik Üniversitesi, Graduate School of Natural and Applied Sciences, Graduate School of Natural and Applied Sciences, Turkey

Approval Date: 2016

Student: ABDULHAMİT BATTAL

Supervisor: AYŞE MERAL YÜCEL

Abstract:

Wheat is one of the main crops to get daily calory requirement for people. Improving wheat yield is one of the most important aims in crop research today. Spike structure genes play a crucial role for yield increase. TtBH-A1 gene has a single nucleotide polymorphism at the conserved domain causing branched spikes producing more spikelet, grains and yield in “Miracle-Wheat”. In this study, TtBH-1 homoeologous (TtBH-A1 and TtBH-B1) gene were screened in tetraploid Kronos Targeting Induced Local Lesions In Genomes (TILLING) population. 80 new alleles were confirmed for TtBH-1 gene. One mutation leading to a premature termination codon was validated for the TtBH-B1 gene in line T4-2432 (Q14*), while a mutation in a conserved domain was validated for TtBH-A1 gene. Glycine at the position 61 of TtBH-A1 protein was converted to serine as a result of mutation of guanine at the position 181 of the gene to adenine in line T4-2447. Supernumerary spikelets were observed in the A-genome homozygous mutant as short branches, whereas no effects were observed in the B genome mutants. Lateral spikelet development leading to additional spikelet side of the normal spikelet was initiated during glume promordium formation according to immature inflorescence observations. T4-2447 mutants produced significantly more spikelet than Kronos . A genome and B genome mutants were combined to make double mutants. TtBH-1 mutations was backcrossed into parental Kronos to eliminate background mutations. Additionally, T4-2447 mutant line and “Miracle-Wheat” was hybridized with Turkish domestic cultivars Kızıltan-91 and Fuatbey-2000. Yield components were evaluated for T4-2447 mutants.