Methods of creating homozygous lines as breeding genotypes in sugar beet (Beta vulgaris) with apozygotic method of seed reproduction

Abstract

Purpose. Investigation of cytogenetic aspects of embryological processes in the culture of immature apomictic embryos, breeding genotypes of sugar beet with cytoplasmic sterility for differentiation and selection by gametophyte reduced parthenogenesis.
 Methods. Cytological, biotechnological, fluorescent cytophotometry, field, laboratory.
 Results. The cytogenetic features of genesis of immature apomictic embryos cells induced in vitro on the 12th, 20th and 22th days of development have been investigated on the basis of CMS apozygotic lines of Beta vulgaris and alloplasmic lines of wild species Beta maritime and Beta patula. Indicators of efficiency of haploid reduced parthenogenesis in vitro in alloplasmic lines significantly exceeded the best technologies in pollen-sterile lines of sugar beet from 3.79% to 6.25% and had a value of 62.2%, 24.8%, and 16.7%, respectively. Stabilization of genome ploidy to diploid was carried out in selected breeding numbers without colchicine, based on evaluation and selection of genome ploidy using software of ploidy analyzer (AP) Partec.
 Conclusions. The efficiency of haploid reduced parthenogenesis induction in vitro in apozygotic CMS breeding genotypes of sugar beet as affected by genetic potential of cytoplasm and taking into account the total percentage of haploids (50 units; 100 units) and myxoploids (50 units; 100 units) has been investigated. Homozygous lines were created by stabilizing the genome ploidy of haploid and myxoploid micro sprouts during III–IV passages without the use of colchicine. Technologies of rooting in the open ground for use in the breeding process of sugar beets have been improved.