杂交种“豫烟11”赖百当二萜含量和腺毛密度的定向改良

Directional improvement of labdanoids content and glandular trichome density of the hybrid‘Yuyan 11’

【背景和目的】豫烟11是由8306与MSK326杂交而来的烤烟品种,因其父本8306腺毛分泌物中含有赖百当二萜而具有晾晒烟的香气特征。为彰显豫烟11的烤烟特色香气风格,对其腺毛分泌物的含量和组成进行定向改良。【方法】利用8306-1(NtCPS2敲除的8306)与MSK326杂交获得豫烟11-1,利用8306-2(NtCPS2、NtCycB2共同敲除的8306)与HK326(NtCycB2敲除的K326)杂交获得豫烟11-2,对其农艺性状、腺毛形态和腺毛分泌物进行测定,并对相关基因序列及表达水平进行分析。【结果】(1)分子检测表明,豫烟11-1、豫烟11-2中的NtCPS2均为突变型;豫烟11-1中的NtCycB2为野生型,而豫烟11-2中的则为突变型。(2)田间试验表明,豫烟11-1、豫烟11-2生长发育正常,农艺性状与豫烟11基本一致;豫烟11-1腺毛密度与豫烟11相比无显著差异,豫烟11-2腺毛密度比豫烟11提高了40.6%;豫烟11-1、豫烟11-2腺毛分泌物中均不含有赖百当二萜,豫烟11-1腺毛分泌物含量与豫烟11相比无显著变化,豫烟11-2腺毛分泌物含量比豫烟11提高了70.2%。(3)qRT-PCR分析表明,豫烟11-1中二萜合成相关基因NtCPS2、NtABS、NtCBTS、NtCYP71D16的表达量与豫烟11相比无显著差异,但在豫烟11-2中则显著提高,而二萜合成上游基因NtGPPS、NtGGPPS的表达量在3个株系间无显著变化。【结论】本研究利用NtCPS2和NtCycB2基因突变,实现了豫烟11腺毛密度、腺毛分泌物组分和含量的定向改良,为针对上述性状的分子育种提供了范例。

[Background]“Yuanyan 11”is a flue-cured tobacco variety derived from the cross of 8306 and MSK326,notable for the aroma characteristics of air-cured tobacco due to the labdane diterpenoids in the glandular trichome secretions of its parent 8306.To highlight the characteristic aroma style of“Yuanyan 11,”directed improvement of the content and composition of its glandular trichome secretions was undertaken.[Methods]“Yuanyan 11-1”was obtained by crossing 8306-1(8306 with NtCPS2 knocked out)with MSK326,and“Yuanyan 11-2”by crossing 8306-2(8306 with both NtCPS2 and NtCycB2 knocked out)with HK326(K326 with NtCycB2 knocked out).The agronomic traits,trichome morphology,and trichome secretions were measured,and the related gene sequences and expression levels were analyzed.[Results](1)Molecular detection indicated that NtCPS2 in“Yuanyan 11-1”and“Yuanyan 11-2”were mutant types;NtCycB2 in“Yuanyan 11-1”was wild type,while in“Yuanyan 11-2”it was a mutant type.(2)Field tests showed that“Yuanyan 11-1”and“Yuanyan 11-2”grew normally with agronomic traits basically consistent with“Yuanyan 11”;the trichome density of“Yuanyan 11-1”showed no significant difference compared to“Yuanyan 11,”while that of“Yuanyan 11-2”increased by 40.6%;neither“Yuanyan 11-1”nor“Yuanyan 11-2”contained labdane diterpenoids in their trichome secretions,and while the secretion content of“Yuanyan 11-1”showed no significant change compared to“Yuanyan 11,”that of“Yuanyan 11-2”increased by 70.2%.(3)qRT-PCR analysis showed that the expression levels of diterpene synthesis-related genes NtCPS2,NtABS,NtCBTS,and NtCYP71D16 in“Yuanyan 11-1”had no significant difference compared to“Yuanyan 11,”but were significantly higher in“Yuanyan 11-2”;the expression levels of upstream diterpene synthesis genes NtGPPS and NtGGPPS showed no significant changes among the three strains.[Conclusion]This study achieved directed improvement of trichome density,trichome secretion components,and content in“Yuanyan 11”through mutations in the NtCPS2 and NtCycB2 genes,providing a model for molecular breeding targeting these traits.