Phenotypic and genotypic characterization of electron beam treated inter-specific (<i>Triticum dicoccum</i> Schrank X <i>Triticum carthlicum</i> Nevski) lines of emmer wheat for leaf rust and stem rust resistance

Cultivated emmer wheat (<i>Triticum dicoccum</i>), a hulled tetraploid species (2n = 4x = 28, AABB) is a minor crop grown in India for its low glycaemic index and high protein (16%) content. However, its genetic variability is limited. This study aims to enhance the variability of cultivated emmer wheat using mutation approach. A tall better yielding, leaf and stem rust resistant inter-specific line (BC₂F₂ line derived from <i>Triticum dicoccum</i> cv. NP200 X <i>Triticum carthlicum</i>) was subjected to physical mutagens (gamma rays and electron beam), with the objective to develop a semi-dwarf, high-yielding, leaf rust and stem rust resistant lines. Mutant and parental lines were evaluated for resistance to leaf rust and stem rust at seedling and adult plant stages and also validated the presence of rust resistance genes through linked molecular markers. Three stable semi-dwarf inter-specific mutant lines with high yield and resistance to leaf rust and stem rust were selected from the electron beam (250 Gy) treated mutagenized population. Seedling and adult plant evaluations displayed resistance to leaf rust and stem rust and molecular marker analyses confirmed the presence of linked marker to stem rust resistance genes (<i>Sr2/Lr27/Yr30, Sr17/Lr14a/Pm5</i> and <i>Sr40</i>) and leaf rust resistance genes (<i>Lr18, Lr50</i> and <i>Lr61</i>) in mutant and parental lines. In addition, plant stature, culm strength and yield improvement was observed as compared to parental lines. The resistance present in the parent lines remained intact in the selected mutant lines even after exposure to electron beam. Mutants thus obtained could be released as cultivars or utilized as a potential source for high yielding, rust resistance for the improvement of emmer wheat. This is the first report of beneficial mutants in emmer wheat using electron beam.