Early Development,Ploidy Identification And Growth Performance Of Gynogenetic Progeny Of The Allotetraploid Pengze Crucian Carp Stimulated By Elopichthys Bambusa

Carassius auratus var.pengsenensis belongs to the Cyprinid,Cyprinid and Carassius which also known as reed crucian carp or Pengze giant carp which is one of the important economic breeding species in China.In order to further enrich the breeding species of Carassius auratus var.Pengsenensis this paper conducts heterogeneous female nuclear development tests based on Elopichthys bambusa as the father and heterologous tetraploid Pengze crucian carp as the mother to study the early development,ploidy and growth performance of the female nuclear development offspring to provide basic data for the research and development of new varieties of Carassius auratus var.Pengsenensis.The main findings are as follows:(1)Fertilized eggs obtained by artificial stem insemination when the embryo developed to the embryonic stage of the original intestine which suggest that the statistical embryo fertilization rate was 35.35±2.88%,the statistical hatching rate after hatching was 33.84±2.16% and the deformity rate was 29.28±1.22% and the statistical emergence rate of piglets after swimming flat is 22.23±3.22%;At a water temperature of 25 ± 1 ℃,the embryonic development of the female nucleus of heteroploid tetraploid Pengze crucian carp stimulated by the Elopichthys bambusa has undergone a total of 27 periods that including fertilized eggs,cleft stage,blastocyst stage,original intestinal embryo stage,neuro embryonic stage,organ formation stage and membrane emergence stage which lasted 50 h 21min and the effective accumulated temperature was 1271.33 ℃·h;By setting up the starvation group and the feeding group,it was found that the time for the Elopichthys bambusa to stimulate the heterologous tetraploid Pengze crucian carp female nucleus to enter the irreversible point was 8 to 9 days after hatching,and the study of the feeding rhythm of the 10 d calves found that the juveniles had a higher feeding rate and feeding intensity at 12:00 and 18:00.(2)By comparing the blood cells of Elopichthys bambusa stimulation heterologous tetraploid Pengze crucian carp female nucleus developmental offspring and Carassius auratus var.Pengsenensis,it was found that the ratio of Elopichthys bambusa stimulation heterologous tetraploid Pengze crucian carp female nucleus developmental offspring to Carassius auratus var.Pengsenensis erythrocyte nucleus volume ratio was 1.98,which was quite different from the theoretical value of 1.33;Shearing the Elopichthys bambusa stimulates heterologous tetraploid Pengze crucian carp female nucleus to develop a daughter fin tissue for cell culture,and primary cells begin to migrate out 10 d to cover the T25 cell culture flask 50% of the bottom area and 17 d to cover the T25 cell culture flask 80%.The passage cells can be covered with 80% of the bottom area of the T25 cell culture flask in 3d to form a monolayer of passage cells that can study the karyotype of chromosomes;100 distinct chromosomal division phases were selected for statistical analysis and the number of chromosomes accounted for 61% between 201 and 210.10 well-divided mid-cell division phases were selected for chromosomal karyotyping and the results showed that there were 24 pairs of central centrimal chromosomes,24 pairs of sub-centro-centrocerosity centromere chromosomes,12 pairs of sub-terminal centrofilament chromosomes,40 pairs of terminal centridoceous centromere chromosomes and 40 pairs of terminal centrosity karyotypes stimulated by xenohalo tetraploid Pengze carp female nucleus,with the number of chromosome arms(NF)=148;The DNA content of triploid Pengze crucian carp was used as a reference to determine the peripheral blood DNA content of the female nucleus of heterologous tetraploid Pengze crucian carp female nucleus developmental offspring.The results showed that the peak of 4N cells in the blood of the female nucleus of the heterologous tetraploid Pengze crucian carp stimulated by the Elopichthys bambusa stimulation was the highest and the peak of 3N cells in the blood of the Carassius auratus var.Pengsenensis was the highest.The peak type is sharp and there is no heterogeneous peak which suggest that the Elopichthys bambusa stimulates the heterologous tetraploid Pengze crucian carp female nuclear development progeny as tetraploid.(3)A 180-day growth comparison experiment was conducted on Elopichthys bambusa stimulation heterogeneous tetraploid Pengze crucian carp female nuclear development offspring and heterologous tetraploid Pengze crucian carp offspring.The results showed that at 180 days,the female nuclear development offspring of heterologous tetraploid Pengze crucian carp stimulated by Elopichthys bambusa was20.5% and 8.6% higher in terms of mass and body length than that of heterologous tetraploid Pengze crucian carp respectively;The absolute weight gain rate of the female nuclear developmental offspring of Elopichthys bambusa stimulation heterologous tetraploid Pengze crucian carp and the heterologous tetraploid Pengze crucian carp offspring of heterologous tetraploid Pengze crucian carp did not change significantly from 0 to 60 days,and the former was significantly greater than the latter at 90 d,120d and 180 d.The absolute weight gain rate of the two was consistent in the180 d test cycle showing a trend of 0-120 d increase,120d-150 d decline and 150d-180 d upward trend;Elopichthys bambusa stimulates heteroploid tetraploid Pengze crucian carp female nuclear developmental offspring and heterologous tetraploid Pengze crucian carp spouting volume reached a maximum of 0.0080±0.0012(g·cm)/d,0.0046±0.0004(g·cm)/d at 90 d and 120 d respectively;In terms of fertilizer fullness,there was no significant difference between 0 and 60 day which indicating that the two seed generations were similar in body size during this period and 90-180 d heterologous tetraploid Pengze crucian carp subgeneration is significantly greater than the Elopichthys bambusa stimulation heterologous tetraploid Pengze crucian carp female nuclear development offspring which indicating that the former is more obese than the latter in this period;According to the growth equations of 0-180 d Elopichthys bambusa stimulation heterologous tetraploid Pengze crucian carp female nuclear development offspring,heterologous tetraploid Pengze crucian carp weight and body length data and the size specifications of the former were more uniform than the latter.