【作者】 胡日生；

【导师】 郭清泉； 赵松义； 朱列书；

【作者基本信息】 湖南农业大学 ， 作物遗传育种， 2007， 博士

【摘要】 中国烟草杂种优势研究和利用起步较早,但发展较缓慢,目前生产用当家烤烟品种全部为常规品种,杂交种并没有其应有的地位,加强杂种优势利用的研究十分必要。本研究按NCⅡ设计,利用3个烤烟胞质雄性不育系和4个国内推广烤烟品种组配12个杂种,系统分析了烤烟杂种经济性状、农艺性状和烟叶品质性状的杂种优势表现,利用加性-显性遗传模型进行烤烟杂种优势的遗传分析,试图利用RAPD标记对48份烟草种质资源进行杂种优势群的划分,并根据RAPD遗传距离和杂种苗期的生理性状与经济性状、农艺性状和品质性状间的相关性,探讨烟草杂种优势预测的可能性。本研究的主要结果有:1、烤烟农艺性状、经济性状和品种性状的杂种优势普遍存在,说明通过杂种优势利用,可以达到改良农艺性状、经济性状和品质性状的目的;组合MsYZ206-9×云烟87和MsYZ216-1×云烟87具有较突出的综合表现,可能具有较好的生产利用潜力。2、烤烟不同性状受到多种遗传效应控制。经济性状产量、上等烟和上中等烟,农艺性状株高、叶长、叶宽和叶长宽比,品质性状上部烟叶总糖、总氮、氯和钾氯比,中部叶烟碱、总氮、氯、糖碱比、氮碱比和钾氯比,下部叶总糖、烟碱、总氮、氯和糖碱比以显性效应为主,在杂种优势利用上有较大潜力;经济性状均价、产值和级指,农艺性状有效叶、茎围、节距和单叶重,烟叶品质性状上部烟叶烟碱和糖碱比同时受较高的显性效应和加性效应控制,既可在杂种优势利用上发掘这些性状显性效应的潜力,又可以在常规杂交育种上通过世代选择加以积累和固定;上部烟叶氮碱比和氧化钾,中部叶总糖和下部叶钾以加性效应为主,杂种优势利用潜力可能不大;烤烟性状(如经济性状和农艺性状)可能存在较大的显性×环境互作效应,环境条件可能对烤烟杂种优势表现有较大的影响,因此对烤烟某个杂交组合的考察必须在不同的环境条件下进行,充分考虑目标性状的综合表现、杂种优势表现及其优势稳定性,才能全面评价杂交组合的优劣和利用价值。3、烤烟有些农艺性状、经济性状、烟叶品质性状间存在显著的遗传相关,大田期利用农艺性状对经济性状和品质性状间接选择和同步改良是可行的;成对性状间可能存在显性主效应×环境互作相关,环境条件可能对杂种成对性状的间接选择和同步改良效果可能有较大影响,因此在不同环境条件下同时进行成对性状间的联合选择,同步改良效果可能会更好。4、16个RAPD随机引物扩增的谱带范围在3～17之间,每个引物平均获得10.4个扩增位点,其中具有多态性的位点为8.2个,平均多态捡出率为78.9%;利用RAPD技术将48份烟草品种被分成6类,基本揭示了烟草种质资源间的亲缘关系和地域关系,但大多数品种的遗传距离集中在0.2～0.4,说明参试材料的遗传基础较狭窄。5、RAPD遗传距离与杂种产量的表型平均值、中亲优势、超亲优势和显性主效应间显著负向相关,可以预测产量杂种优势潜力大小;成苗期叶片Chla/b和SOD活性可作为烤烟杂种部分农艺、经济和品质性状优势组合选择的参考指标。更多还原

【Abstract】 The heterosis utility of flue-cured tobacco,introduced earlier in China,develop slowly and lag much behind America and Brazil.At present,the varieties of flue-cured tobacco,spreading in most China,are all conventional varieties,and flue-cured tobacco hybrid never attains its rightful position in Chinese tobacco production.Therefore it is necessary to strengthen the studies on heterosis utility of flue-cured tobacco.In the experiment,12 hybrids crossed among 3 cytoplasmic male sterile lines,bred in Central-South Agricultural Experiment station,CNTC,and 4 varieties of flue-cured tobacco popularized in China were used to determine the heterosis and its genetic effect in economic,agronomic and quality traits;RAPD markers were used to classify heterotic group of 48 genetic resources of tobacco,and the possibility of heterosis prediction,by RAPD genetic distance and physiological means,was discussed.Results were as following:1.The heterosis for economic,agronomic and quality traits,was found in most crosses,which indicated that improvement of economic,agronomic and quality traits by heterosis utility was possible.Perfect Crosses of MsYZ206-9×Yunyan87 and MsYZ216-Yunyan87 showed big potentiality in tobacco production.2.Flue-cured tobacco’s different characters are controlled by several genetic effects.Yield,top-class tobacco and high-class tobacco;plant height,leaf length, width and length-width ratio;TS,TN,Cl,and K₂O/Cl in upper leaves,Nic,TN,Cl, TS/Nic,TN/Nic and K₂O/Cl in cutters,TS,Nic,TN,Cl,and TS/Nic in lower leaves are mainly controlled by dominance effects,which has more potency on the utilization of heterosis.Average price,production value and class index;leaf harvested,stem girth,pitch and single leaf weight;Nic and TS/Nic in upper leaves of quality characters are highly controlled by dominance effects and additive effects at the same time.Not only can these traits’ dominant effects’ potency be exhumed with the utilization of hybrid superior,but also they can be accumulated and fixed by selection in routine cross-breeding.TN/Nic and K₂O in upper leaves;TS in cutters and K₂O in lower leaves are controlled mainly by additive effects,which has less potency on the utilization of heterosis.Dom.*Evn.effects of some characters,such as economic and agronomic traits,showed significantly different at 0.05 or 0.01 levels, and the environments,the Mshybrids of flue-cured tobacco growing in,might have great influence on hybrids heterosis.In order to give a comprehensive evaluation on crosses and their value of utilization,it is necessary to make an on-the-spot investigation on the crosses under different environment.3.Genetic correlation with significant difference at 0.05 or 0.01 levels, between Some agronomic traits and economic,quality traits of flue-cured tobacco, was found.So it is possible for economic characters and quality traits to be synchronously improved by indirect selection based on agronomic traits during the growth season.Dom.* Env.Cor significantly different at 0.05 or 0.01 levels,exist in some pair-traits,and environment has great effects on the synchronous improvement by indirect selection for some pair-traits.Therefore,the results of synchronous improvement may be better by indirect selection in different environments.4.About 3 to 17 bands were amplified among 16 RAPD primers.Each primer produced average 10.4 bands in total,8.2 polymorphic fragments,and the frequency of polymorphism was 78.9%.48 tobacco varieties were classified into six clusters by using RAPD markers,which radically revealed the genetic relationship and source region of these germplasms.The genetic background of the varieties involved,whose genetic distance mainly varies from 0.2 to 0.4,is narrow.5.The negative genetic correlation between the genetic distance,based on RAPD markers,and Heterosis apart from mid-parent,heterosis over high-parent,and dominant effect of F₁ yield was significantly different at 0.05 or 0.01 levels,which indicated that flue-cured tobacco parents with less genetic distance could get F₁ hybrids with stronger heterosis in yield.Chla/b and SOD activity in seedling stage might be favorable reference index in the improvement of agronomic,economic and quality traits of flue-cured tobacco hybrids.更多还原