Screening Of Outstanding Trait Marker Genes In Progenies Of Castor Hybrids Based On Proteomics Technologies

Castor is one of the top ten oil crops in the world,which has high economic value.Breeding new varieties with high yield,high oil content and resistance to stress has always been the goal of castor breeding,and hybridization is the most direct and effective method,so it is particularly important to predict the good characters of hybrid progenies.In this experiment,the castor female line Lm aLmAB2,male line CSR-181 and their hybrid offspring seeds were taken as the research objects.Combined with the determination of quality index,physiological and biochemical index and differential proteomics technology,we found out which good characters of castor hybrid offspring compared with their parents,and filter the genes related to these characters.Then select 5 castor hybrids with better performance in production and their parents for screening gene RT-qPCR analysis.The experimental results are as follows:The quality indexes of female line aLmAB2,male line CSR-181 and their hybrid offspring were determined:With the development of time,the 100-grain weight of seeds,kernel percentage,crude fat content,content of most fatty acids,especially ricinoleic acid showed a trend of higher offspring(especially F1)than parents,this shows that the seeds of hybrid offspring have a heterosis over their parents in terms of 100-seed weight,seed kernel rate,crude fat content,and various fatty acid content.The results of physiological and biochemical indexes showed that the activities of SOD,CAT,GST,POD,T-AOC and the content of soluble protein in the seed ROS scavenging system were better in offspring(especially F1)than parents with the development of time;Correspondingly,the contents of H2O2,OFR and MDA in offspring(especially F1)were lower than those in parents,this indicates that the seeds of the hybrid offspring show heterosis over their parents in terms of seed resistance.The results of differential proteomics analysis correspond to the results of quality index and physiological and biochemical indexes:some of the up-regulated differential proteins in the seeds of offspring are related to seed oil synthesis,fatty acid synthesis and metabolism,which is consistent with the results of quality index measurement,that is,in terms of seed oil synthesis,fatty acid synthesis and metabolism,the offspring of hybrids show heterosis over their parents;most of the up-regulated differential proteins in the seeds of offspring are related to seed yield and stress resistance,which is related to the results of physical and biochemical indexes were consistent,that is,in terms of seed yield and stress resistance,the offspring of hybrids showed heterosis over their parents.Based on this,we selected 12 differential proteins corresponding genes related to seed oil synthesis,pollen abortion,yield and stress resistance for RT-qPCR analysis.The results showed that the gene expression levels of the 12 differential proteins were consistent with the protein expression levels.Using marker genes to predict heterosis of five castor hybrids with good performance in production.The results showed that TB16 and TB13 showed greater heterosis in terms of seed oil synthesis ability;TB18 and TB11 showed greater heterosis in terms of reducing pollen abortion;There was no significant difference among TB 18,TB16,TB13,TB11 and TB17 in terms of seed yield and resistance.