【作者】 宋波；

【导师】 袁希汉；

【作者基本信息】 南京农业大学 ， 蔬菜学， 2008， 硕士

【摘要】 有棱丝瓜和普通丝瓜彼此之间具有多种互补的优良性状。普通丝瓜产量较高,品质柔软,存在对病毒病免疫的品种,但果皮碰擦后易褐变,影响商品外观,且果肉在烹饪过程中也易变褐,影响到食品色泽;有棱丝瓜品种中品质较普通丝瓜佳,且果肉在烹饪过程中不变色保持翠绿、口感也好,但缺乏抗病毒病的抗源。为了快速有效地利用上述的优良性状来改良有棱丝瓜或者普通丝瓜,本研究在种间杂交F₁代的研究基础上,采用形态学、细胞遗传学以及分子标记技术对丝瓜种间杂交后代（F₁、F₂、B₁、B₂）遗传特性进行了研究。具体结果如下:1有棱丝瓜×普通丝瓜的种间杂种F₂代株高、叶片数、叶横径、叶纵径、节间长、瓜柄长、第1雄花节位、第1雌花节位、雌花数、瓜长果实发育速度、瓜径果实发育速度、瓜长共12个农艺性状以及花粉活力观察的结果表明,F₂代农艺性状发生较大分离,产生了大量的变异类型,F₂代花粉活力变幅较大,平均花粉活力较F₁代低,但不存在花粉严重不育问题。2对有棱丝瓜×普通丝瓜杂种后代的苦味、开花时间、棱与花色4个农艺性状的遗传特性进行了初步研究,结果表明:4个性状均发生较大分离,苦味可能受两对显性互补基因控制,开花时间、棱以及花色遵循数量性状遗传规律。3对有棱丝瓜、普通丝瓜以及有棱丝瓜×普通丝瓜杂种后代F₁、F₂花粉母细胞的减数分裂行为进行了研究,结果表明:两亲本减数分裂正常,而F₁、F₂减数分裂各时期均存在不正常现象,且F₂单株间具有不同程度的不正常减数分裂。主要表现在:中期Ⅰ有赤道板外染色体;后期Ⅰ出现落后染色体,四分体时期出现二分体、含微核的异常二分体、三分体、含微核的异常四分体及多分体。花粉母细胞减数分裂不正常是丝瓜种间杂种后代育性降低的细胞学原因。4利用正交试验设计,从Taq DNA聚合酶、dNTPs、引物、Mg²⁺4种因素各3个水平来优化丝瓜ISSR反应体系。结果表明,在20μL反应体系中初步确定各反应成分为:10×PCR buffer,2.5mmol/L Mg²⁺,30ng丝瓜模板DNA,ddH₂O,1U Taq酶,250μmol/LdNTPs,0.25μmol/L引物,并通过梯度PCR测验,确定55.8℃为适宜的退火温度。这一体系的建立为丝瓜种间杂种后代ISSR分析奠定了技术基础。5为了揭示有棱丝瓜×普通丝瓜种间杂种后代的遗传分离规律,将亲本、杂种F₁、F₂和B₁代用9个引物进行ISSR-PCR扩增。共扩增出48条带,其中双亲共有的带29条,普通丝瓜特异带9条,有棱丝瓜特异带20条。带型统计分析结果表明在丝瓜种间杂种后代中普通丝瓜的遗传物质比有棱丝瓜的遗传物质略能够传递给后代。在回交后代中普通丝瓜的遗传物质比在自交后代中丢失更快。更多还原

【Abstract】 Luffa acutangula（L.） Roxb（2n=26） and Luffa cylindrical（L.） Roem（2n=26） possesses many complementary valuable traits.Luffa cylindrical（L.） Roem possesses high yield, disease resistance for Luffa acutangula（L.） Roxb,including disease resistance to virue and increase of production.Meanwhile,Luffa acutangula（L.） Roxb has good edible qualities and the flesh without browning after cooking for Luffa cylindrical（L.） Roem,including improvement of qualifies,without browning after cooking and so on.In the present study,the different categories of Luffa were used as core material for further investigation based on former research progresses.The hybrid progenies（F₁、F₂、B₁、B₂） have been gotten via the interspecific cross.Studies on genetic characteristics of the hybrid progenies（F₁、F₂、B₁、B₂） from the interspecific cross with morphology,further cytogentic and molecular analyses. The detailed results as following:1 Segregations of plant height,leaf number,leaf width,leaf length,node length,first stalk length,first note of male flower,first note of female flower,female flowers number,rate of fruit development,fruit length and pollen viability in F₂ progenies derived from interspecific cross Luffa acutangula（L.） Roxb×cylindrical（L.） Roem were observed.The results showed that the interspecific F₂ progenies segregated transgressively,forming much variation.F₂ pollen viability is lower than F₁.F₂ has lower worthiness in breeding utilization.2 Through analysis of genetic characterization on four agronomic traits of the hybrid progenies from the interspecific cross Luffa acutangula（L.） Roxb×cylindrical（L.） Roem, bitterness,flowering time,arris,flower color four traits were studied.The results showed that the bittemess in hybrid progenies may be a quality character determined by the two genes which were independent genetic relatively.The relation between the genes was dominant supplement each other（DSEO）.Flowering time,arris,flower color follow heredity of quantitative characters.3 Cytological studies were conducted on pollen mother cells（PMCs） meiosis of hybrid progenies from the interspecific cross Luffa acutangula（L.）Roxb×cylindrical（L.） Roem.Resuit showed that two parents have normal meiosis of PMCs.However,hybrid F₁,F₂ have abnormal meiosis of PMCs,there were particularities in metaphaseⅠ,some of the chromosomes were found not to rank at metaphase plate in metaphaseⅠ.In anaphaseⅠ,there were lagged chromosomes.At tetrad stage,dyad,dyad with mocronucleus,triad,tetrad with mocronucleus and polyad appeared.Abnormal meiosis of PMCs was the cytogenetic reason for fertility reduction of hybrid progenies.4 Orthogonal design was used to optimize ISSR amplification system on Luffa In four factors(Taq DNA polymerase,Mg²⁺,dNTPs,primers)at three levels respectively.A suitable ISSR reaction system was established,namely 20μL reaction system containing 10×PCRbuffer, 2.5mmol/LMg²⁺,250μmol/LdNTPs,0.25μmol/Lprimer,1UTaq DNA polymerase,and 30 ng DNA template.The optimal annealing temperature for ISSR-PCR reaction was proposed by gradient PCR.5 This study was carried out in order to uncover the laws of genetic segregation in the interspecific progenies from Luffa acutangula（L.）Roxb×cylindrical（L.） Roem.The DNAs isolated from the parents,F₁ hybrid,F₂ and B₁ progenies were amplified for ISSR analysis using 9 primers.Forty-eight bands were amplified,among which 19 bands were common to both parents,20 and 9 bands were Luffa acutangula（L.）Roxb and Luffa Cylindrical（L.）Roem -specific,respectively.Statistical analysis of the band pattems showed that F₂ progenies inherited more genetic components from Luffa cylindrical（L.）Roem than from Luffa acutangula（L.） Roxb.The genetic component from Luffa cylindrical（L.） Roem was eliminated in B₁ progeny faster than in F₂ progeny.更多还原