芝麻染色体加倍突变体的鉴定及生物学性状分析

Identification and Biological Characteristics Analysis of Chromosome Doubling Mutants in Sesame

为探索染色体加倍对芝麻染色体核型和生物学特征的影响,本研究对通过EMS诱变创制获得的97个染色体加倍突变体开展流式细胞仪倍性鉴定、染色体组验证、核型特征分析,并选取其中1份种质(M1-01)与其二倍体(豫芝11号)进行生物学性状比较分析。染色体观察结果显示,与二倍体相比,四倍体突变体的染色体数目由26条增加至52条;染色体组型为3B,对称性较二倍体降低。生物学性状比较显示,四倍体突变体较二倍体花期延长11 d,生育期延长15 d,株高增加31.20 cm,茎粗增加0.63 cm,花冠长和宽分别增加0.28 cm和0.44 cm,蒴果宽和厚分别增加0.25 cm和0.39 cm,而单蒴粒数仅为10粒,较二倍体降低86.11%,结实率极差,且单株产量显著降低,降幅达83.82%。四倍体突变体籽粒油脂含量降低至37.54%,较二倍体下降14.85个百分点,而蛋白质含量为23.53%,较二倍体增加2.63个百分点;油酸含量提高12.43个百分点,亚油酸含量则下降11.24个百分点,油酸和亚油酸比值由0.88提高到1.54。本研究结果可为芝麻重要性状遗传研究及四倍体种质利用提供重要信息和理论支持。

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.