A method for obtaining regenerated cucumber plants by inducing gynogenesis through culture of unfertilized ovules

Abstract

The invention relates to a method for obtaining a cucumber regenerated plantlet by inducing gynogenesis by virtue of culture of unfertilized ovules in vitro. The method comprises the following steps: inoculating complete ovaries before female flowers of cucumber bloom on a pre-culturing culture medium added with TDZ using an MS culture medium as a base for performing primary induction; longitudinally cutting the complete ovaries subjected to primary induction along a center line, stripping unfertilized ovules and inoculating on an IM3 induced culture medium containing KT and BA; after differentiating embryoids to form cotyledons and radicles, transferring the embryoids into the MS culture medium for continuously growing and developing to obtain a complete regenerated plantlet; and numbering by adopting a root tip cell chromosome and identifying the ploidy by adopting a flow cytometry to successfully obtain haploid and diploid plants. According to the method, the research base of culturing haploids of the cucumber is laid, and the technical support is relatively provided for cross hybridizing, molecular marker, genetic map construction and gene mapping.

Description

technical field [0001] The invention relates to the field of plant tissue culture, in particular to a cucumber tissue culture and plant regeneration method. Background technique [0002] Cucumber (Cucumis sativus L.) is an important protected vegetable crop in my country. As the cultivation area expands year by year, the market requirements for cucumber varieties are increasing in terms of disease resistance, stress tolerance, yield and commerciality. The selection efficiency of cucumber quality and disease resistance is not high, and it usually takes 6-8 years to breed a new variety. Haploid culture provides the possibility to shorten the breeding period and improve the breeding efficiency. Since the obtained haploid plants often undergo the phenomenon of chromosome self-doubling and then form double haploid (DH) plants, there is no dominant recessive effect of allele loci, so that the traits controlled by recessive genes can also be fully obtained. It is reflected that th...

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Problems solved by technology

However, there are still many deficiencies in the current research on cucumber gynogenesis-induced plant regeneration: First, the test materials are all conventional species and inbred lines of North China Mici and European greenhouse types, and the Eurasian hybrid type that is extremely important for breeding research Cucumber has not seen any related research reports, so it brings great limitations to the application of haploid breeding on cucumber; secondly, although there are many researches on cucumber gynogenesis at home and abroad, they are all based on unpollinated The ovary is an explant. As mentioned above, the embryo is easily affected by the ovary wall tissue during its development, so the deformity rate is high and it is difficult to obtain a complete regenerated plant; finally, due to the current gynogenesis Most of them go through the callus pathway, and there is seldom the embryoid body pathway for direct seedling formation, so problems such as mixed chromosomal ploidy of regenerated plants are very prone to occur

The ultimate goal of gynogenesis is to obtain homozygous double haploid materials, and ploidy mixed materials cannot be used in breeding and research, thus limiting the development of haploid research

So far, there has been no research report on obtaining embryoid bodies and regenerated plants by inducing gynogenesis of unfertilized ovules from Eurasian hybrid cucumbers

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