Obtaining And Identification Of Cytoplasmic Male Sterile From Maize CF3 Line

Maize has become the largest grain crop in China,and it is also the crop with the most extensive use of heterosis.The production of hybrid seeds using male sterility can significantly reduce hybrid seeds price,improve seed purity,and take advantage of hybrid seeds,hence,hybrid vigor has important application value.Cytoplasmic male sterility(CMS)has been widely used in crop heterosis utilization.However,maize CMS is limited in maize application because of some shortcomings of maize CMS,and Finding and creating better maize CMS lines is still one of the most important research topics in maize cross breeding.In this study,we found a cytoplasmic male sterile line in the construction of corn near-isogenic line material.Using Genetic analysis,cytological observation,and molecular identification technologies,we conduct in-depth analysis and research on the obtained male sterile line.The main results are as follows:1.We found a cytoplasmic male sterile line from nearly isogenic line of hybrid offspring of the maize inbred lines chang 7-2,and PH4CV,named CF3 sterile lines,and further obtained sterile lines CZ58 through hybridization with inbred lines zheng 58.CF3 sterile lines and derivative CZ58 presented shorter anthers,and no exposing,and no pollen spilling out.2.Genetic analysis showed that CF3 was CMS type infertility,with a wide range of restorer lines,complete male flower abortion and stable sterility,indicating that CF3 possesses better application value.3,Using freehand section and paraffin section method,we carried out the cytological observation,the results showed that the anthers of CF3 and CZ58 could produce a small amount of pollen,but the pollen presented abnormality.The pollen appears round or irregular transparent,and can’t be TTC staining,indicating they have no pollen activity.These results indicated CF 3 belonged to the gametophyte sterility,consisting with characterization of CMS-S type cytoplasmic sterile lines.4.Specific PCR amplification was performed on CF3 and CZ 58 using the primers of CMS sterile lines of maize.CF3 and CZ58 were amplified bands only using the specific primers of CMS-S,indicating that the CMS sterile lines were CMS-S sterile lines,and further DNA sequencing showed that the mitochondria of the CMS sterile lines were type S.Totally,we obtained a new cytoplasmic male sterile line CF3 and its derivative line CZ58 in maize,which belongs to CMS-S cytoplasmic male sterile line,with stable sterile characters and complete abortion,and has a good utilization value in the breeding of maize hybrids.This study provides a new material for the utilization of CMS-S in maize cross breeding.