Apomixis and the problem of obtaining haploids and homozygote diploids in pear (Pyrus communis L.)

• Published in: Plant varieties studying and protection no. 1(18); pp. 22 - 25
• Main Authors: Долматов, Є. О., Джафарова, В. Є.
• Format: Journal Article
• Language: English
• Published: Ukrainian Institute for Plant Variety Examination 01.02.2013
• Subjects: apomixis; cytokinins; diploidy; haploidy; homozygosity; hybridization; hybrids; meiosis; parthenogenesis; pears; pollination; Pyrus communis
• ISSN: 2518-1017; 2518-7457; 2518-7457
• DOI: 10.21498/2518-1017.1(18).2013.58699

The article highlights results of research over simulative apomixes in pear and its utilization for obtaining haploids and homozygote diploids. It has been established that over 50% pear varieties with failed remote hybridization are capable of generating seeds of apomictic origin producing diploid plants. Genotypes displaying maximal inclination to apomixes have been singled out. Apomictic pear seedlings obtained from foreign pollination within the limits of the same combination are inherent in profound morphological diversity. Fruit-bearing apomicts originated from one and the same maternal plant differ to the same extent as hybrid seedlings of the same family. Genetic markers have enabled to establish that these are embryo sacs in which meiosis has completed that give rise to apomictic seeds. In vitro method as used for the purpose of increasing apomictic plants output has been illustrated. The greatest induction of apomictic shoots in vitro has been reached by alternation of BAP cytokinin at concentration of 1mg/l and 2 mg/l on the background of GA3 amounting to 1,5 mg/l. Grafting with shoots in vitro on non-sterile rootstocks of pear (Pyrus communis) has increased the output of plants up to 80%. A cytological assessment of 9 apomictic samples is provided. The cytological analysis of samples of apomictic forms has certified the presence of simulative haploid parthenogenesis in pear.