Research On Gynogenesis To Induce Haploid Plants In Cucumber (Cucumis Sativus L.)

Haploid natural spontaneous occurrence’s probability is very low, and requires an efficient screening tool for screening. By artificially induced haploid technology can greatly increase the probability of occurrence. Application materials can greatly shorten the haploid breeding process. If we had an efficient technology to culture haploid of cucumber well be bound to change the existed breeding methods. In this study we try to use radiation pollen pollination, culture the unpollinated ovary slices, and by the occurrence of distant pollen pollination to induce cucumber haploid. We try to get a method to improve the frequency of occurrence of haploid plants.This research results were as follows:1. Studies on Induction of Haploid Cucumbers by Irradiated Pollen PollinationUsing irradiated pollen pollination combined with embryo rescue is one of the important method to induce haploid and double haploid (DH). In order to study the effects of cucumber genotype and irradiation dosages on the induction of haploid reproduction,20 different cucumber genotypes were used as maternal parents,3 different cucumber genotypes as the paternal parents, and pollens radiated by 3 different dosages (150GyN 250Gy、350Gy). The results indicated that the plant regeneration rate from 150Gy was higher than that from 250Gy and 300Gy.’5211’from 150Gy had the highest plant regeneration rate 3.92% and haploid regeneration rate 1.96%. Under lower dosage (150Gy) treatment, plant regeneration rate varies, while under higher dosage (300Gy) plant regeneration rate was low with small variation. Statistics indicated that the effect of the radiation dose was larger than the genotype; the radiation dose is the main factor to affect the plant regeneration rate.6 genotypes which occupied 60% among all genotypes failed to induce plantlets,4 genotypes which occupied 40% among all genotypes induced plantlets, variation of induction efficiency ranged from 0.26 to 0.54. Induction rates of different genetypes had diversity.2. Study on unpollinated ovary culture in cucumber Haploid was induced by Unpollinated ovary culture in this study.18 treatments in different combinations were used on the induction study. NO.13 treatment had the highest rate, but in the following culture the ovule easily turned to callus, other treatments adding NAA treatments also had this phenomenon. We will use medium:MS+0.02 mg/LTDZ +0.2 mg/L6-BA for the following study.3. Study on wide hybridization induce haploid in cucumberUse of wide crosses between, rather than within, a speciesis one of the most effective methods for haploid induction and has been used successfully in many species. The number of seed examined in these studies and the haploid frequencies vary greatly. We need to expand the number of samples in the future study.