Identification and Biological Characteristics Analysis of Chromosome Doubling Mutants in Sesame

Ma Qin; Gao Penghua; Li Sida; Ju Ming; Wang Huili; Zhang Xintong; Duan Yinghui; Zhang Haiyang; Xu Guizhen; Miao Hongmei

doi:10.14083/j.issn.1001-4942.2024.09.005

Abstract：To explore the effects of chromosome doubling on karyotype and biological characteristics of sesame,the ploidy identification by flow cytometer,chromosome set determination and chromosome karyotype analysis were performed in 97 tetraploid sesame mutants created by EMS mutagenesis,and the biological char-acteristics of one mutant were compared with its diploid(Yuzhi11).The results of chromosome observation showed thatcompared with the diploid type,the number of chromosome in the tetraploid mutants increased from 26 to 52,the chromosome karyotype was 3B,and the symmetry reduced.The biological characteristics compa-ration indicated that compared with the diploid mutant,the flowering period and growth period of the tetraploid mutant were 11 days and 15 days longer,respectively;the plant height increased by 31.20 cm,stem diameter increased by 0.63 cm,corolla length and width increased by 0.28 cm and 0.44 cm respectively,and capsule width and thickness increased by 0.25 cm and 0.39 cm respectively;however,the setting rate was very poor with seed number per capsule as 10,which was 86.11％lower than that of diploid mutant;the yield per plant reduced significantly by 83.82％.In the tetraploid mutant,the oil content decreased to 37.54％with a de-crease of 14.85 percentage points,and the protein content was 23.53％with an increase of 2.63 percentage points compared with diploid mutant,respectively.The content of oleic acid increased by 12.43 percentage points and the content of linoleic acid decreased by 11.24 percentage points,and the ratio of oleic acid to lino-leic acid increased from 0.88 to 1.54.These results could provide valuable information and theoretical supports for genetic analysis of key traits and tetraploid germplasm utilization in sesame.