Chaudhary, H.K.Katoch, Ajeta2022-05-132022-05-132020-12-10https://krishikosh.egranth.ac.in/handle/1/5810184702The research endeavour entitled “Relative fertility frequency amongst first generation doubled haploids induced in bread and durum wheats following Zea mays and Imperata cylindrica- mediated chromosome elimination approach” was executed in the Department of Genetics and Plant Breeding, CSK HPKV, Palampur during the years 2018-19 with the goal to determine the relative fertility frequency of the first generation doubled haploids in bread and durum wheats induced following maize and Imperata cylindrica- mediated doubled haploidy breeding approaches. The material for the present investigation comprised of sixteen bread wheat genotypes, seven durum wheat genotypes and three wheat × rye derivatives (BC1F3) which were utilized as female parents while Z. mays and I. cylindrica were used as pollen source. Hybridization programme was carried out with both the pollen sources to obtain haploid plantlets. These haploid plantlets were then subjected to colchicine treatment to obtain doubled haploids. Different haploid induction and doubled haploidy parameters like pseudoseed formation frequency, embryo formation frequency, haploid plant regeneration frequency, haploid formation frequency and doubled haploid formation frequency were recorded for all the genotypes. Each genotype showed differential response to callus formation, plant regeneration and haploid & doubled haploid formation. I. cylindrica outperformed maize for all the parameters in bread wheat, durum wheat and wheat × rye derivatives. A total of nineteen doubled haploid plants were formed in different wheat genotypes. Fifteen DHs were formed in bread wheat (twelve with I. cylindrica as pollen parent and three with maize as pollen parent) and four were formed in durum wheat (three with I. cylindrica as pollen parent and one with maize as pollen parent). The genetic origin of the uniparental elimination derived DHs is not always certain, therefore screening techniques are needed to validate fertility behaviour of DH plants in further generations. The first generation doubled haploids obtained were bagged with butter paper bag at head emergence stage to avoid the contamination with other pollen and the bagged spikes were harvested individually. The seed setting frequency of the DH plants was assessed and compared with each other and the parents. Amongst the DHs formed NDH1, NDH3, NDH6, NDH9, NDH12 and NDH 13 performed significantly better whereas no significant difference was observed when compared with the parents for seed setting frequency. The results showed that first generation doubled haploids are indeed true doubled haploids and can be used for various genetic and molecular studies.EnglishThesis