Creation Of DW871 Colored Rapeseed Germplasm Of Brassica Napus Using Microspore Culture Technolog

As a new tourism development resource,color rape has the advantages of easy planting,easy management,bright color,long flowering period,wide adaptability,and can be used as oil,ornamental and other advantages.At present,color rape is generally reported as conventional tall-stalk Brassica napus,which is prone to lodging,stringing branches and inflorescence bending in rainy days,which affects the ornamental effect.Therefore,it is one of the breeding goals of ornamental rape to breed new colored rape germplasm with good quality,suitable plant type,lodging resistance and no branching.In this study,DW871 that has special inflorescence characteristics and great ornamental value was used as the base material.After hybridization crossing with common colored high stalk rape,F₁generation was used to discuss the factors affecting the embryo rate and seedling rate in the process of microspore culture,and create new colored rape which has DW871 specific inflorescence traits and excellent quality.The main research contents and results are as follows:1.Effects of donor plant genotype and developmental state on the embryo rate of microspore.In microspore culture of 10 rape genotypes,the frequency of embryoid formation was 70%.There were significant differences in embryoid formation rate among different genotypes,among which DZ238 had the highest embryo development rate（507 embryos/bud）.The effects of different bud lengths on the embryo yield of DW871 and white flower hybrid combination DZ401 were tested.It was found that there was a significant difference in the embryo yield of different bud lengths at the initial flowering stage.With the increase of bud length,the embryo yield first increased and then decreased,and the embryo yield of the two materials was the highest when the bud length was 4.0～4.49 mm.The experiment of embryo rate at different growth stages showed that the embryo rate was the highest at full flowering stage.2.Effect of culture conditions on the embryo rate of microspore.Using DW871and white flower hybrid DZ401 as materials for microspore culture,the effects of sucrose concentration and low temperature（4℃）preservation time on microspore embryo rate were discussed.The results showed that the embryo genesis time of the sucrose culture group that of high concentration and then low concentration,was 5—7d earlier than that of the CK group,and the embryo yield was the highest under the treatment of 2 days of NLN-16 culture after NLN-13 culture.With the extension of low-temperature（4℃）storage time,the rate of microspore embryo formation decreased,and the low-temperature storage time should not exceed 2 days.3.Effects of embryo age and hormone combination on seedling emergence rate.When the embryo age reached 40 days,cotyledon embryos of DZ237 and DZ242were transferred to MS solid medium containing different hormone ratios.It was found that the seedlings were successfully induced only in MS solid medium containing 0.5mg/L6-BA and without any hormone.The microspore emergence rate of rape with embryo age over 40 days was low,and with the increase of embryo age,the microspore emergence rate of each genotype decreased gradually,and embryoids with embryo age over 52 days did not induce seedling emergence.4.Transplanting DH plants and its botanical investigation.DW871 that has special inflorescence characteristics were used as parents for hybridization crossing with common colored high stalk rape,after microspore culture was performed on 7obtained hybrids F_1.A total of 104 regenerated plants were obtained,and plants survived after being transplanted into the field with a survival rate of 89.42%.The botanical characters of DH plants during the whole growth period were investigated,and the results showed that a total of 60 DH plants were male normal fertility.From the aspect of flower color,four kinds of rape colors were obtained,which were white flower,yellow flower,orange red and kumquat.From the perspective of plant type,there are three plant types,including common Brassica napus tall-type,DW871specific inflorescence type and DW871 multi-stem type similar to Gypsophila.5.Character on investigation of color DW871 germplasm in Brassica napus L..A survey of agronomic character and quality analysis were conducted on 23 Brassica napus color DW871 germplasm obtained.Compared with the parent DW871,the plant type showed DW871 specific inflorescence traits,with higher number of primary branches and slightly higher oil and protein content than the parent;after comprehensive evaluation,it was found that Y57 is a high-quality colored rapeseed new germplasm that has dwarf stalk,kumquat color petal and"double low"quality,being familiar with special inflorescence of DW871.The plant height of Y57 is 88cm,which has 18 primary branches,39%of oil content,25.96%of protein content,0.95%of erucic acid and 28.15μmol/g of glucosinolate.Y57 is a new colored germplasm of DW871 that may have ornamental and oil value and high application prospect.