Relative haploid induction and fertility efficiency in hexaploid, tetraploid and wheat × rye derivatives following Zea mays and Imperata cylindrica-mediated chromosome elimination approach

Ajeta Katoch; Harinder Chaudhary; Vinod Sood; Kritika Singh; Shubham Verma; Amit Rana

Just Accepted

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Relative haploid induction and fertility efficiency in hexaploid, tetraploid and wheat × rye derivatives following Zea mays and Imperata cylindrica-mediated chromosome elimination approach

Ajeta Katoch, Harinder Chaudhary, Vinod Sood, Kritika Singh, Shubham Verma, Amit Rana

Abstract

Context: In plant breeding, rapid development of homozygous lines is vital for accelerating varietal improvement. While doubled haploidy (DH) breeding enables the production of fully homozygous lines in a single generation but the effect of uniparental elimination following inter-generic hybridization on seed fertility remains unclear. Aims: To determine reliable and efficient approach of DH breeding using diverse panel of wheat types using Imperata cylindrica and maize as pollen sources and to estimate the relative fertility of the first-generation DHs. Methods: Inter-generic hybridization using pollens of composite variety of maize and I. cylindrica with sixteen hexaploids, seven tetraploids and three wheat × rye derivatives (BC1F3) were carried out and various haploid and DH induction parameters were evaluated. General combining ability (GCA) analysis was conducted to identify superior lines and the DHs developed were assessed for seed setting frequency. Key results: Significant differences were found for most haploid induction parameters. GCA tests identified hexaploid genotypes (DH 86, HS 295, HPW 155) and tetraploid genotypes (A-9-30-1, PDW 314, PDW 191) as superior combiners, while I. cylindrica emerged as the most effective pollen source, especially in hexaploid wheat genotypes. Nineteen new first-generation DHs were developed with seed setting at par to their parental variety. Conclusions: I. cylindrica proved to be a more effective pollen source than maize for DH production in wheat and the new DHs developed were true to type. Implications: DH breeding can accelerate wheat breeding programs by producing homozygous lines efficiently while retaining fertility levels similar to their parent lines.

CP24339 Accepted 13 February 2025