【作者】 闫立英；

【导师】 陈劲枫；

【作者基本信息】 南京农业大学 ， 蔬菜学， 2009， 博士

【摘要】 黄瓜(Cucumis sativus L.)是我国重要的蔬菜作物,单性结实性是黄瓜与产量有关的重要经济性状,也是保护地专用黄瓜品种选育主要的育种目标之一。正确评价黄瓜种质资源单性结实性、深入理解其生理机制与遗传规律、筛选与单性结实性紧密连锁的分子标记,是黄瓜遗传改良的基础。本文在对75份黄瓜种质资源单性结实性系统评价的基础上,基于单性结实性稳定的欧洲温室型雌性系‘6401’和雌雄同株自交系‘6457’与非单性结实自交系‘6429’和‘6426’,采用植物数量性状主基因+多基因混合遗传分析方法,对黄瓜单性结实性进行了多世代联合分析；并对‘6457’中自然发生的超级子房的生长发育规律和内源激素进行了研究；采用BSA法筛选了与黄瓜单性结实性相关的分子标记,以期为黄瓜单性结实性遗传改良提供依据。取得了以下主要结果：1黄瓜种质资源单性结实性评价河北昌黎春季日光温室条件下,75份黄瓜种质资源单性结实性评价结果表明,单性结实率在0～100%呈连续分布,不同黄瓜种质资源单性结实性间存在极显著差异。75份种质资源中,强单性结实材料40份,占53.3%,中等单性结实材料24份,占32%,弱单性结实材料11份,占14.7%。其中的24份品种资源中,强单性结实品种20份,占83.3%,其余为中等单性结实。黄瓜单性结实性强弱表现为座果率的差异,一般随着节位的升高而增强,其评价工作可侧重于20节内的低节位。南京春季塑料大棚条件下,55份黄瓜种质资源单性结实性评价结果表明,单性结实座果率≥70%的种质资源4份,40%～70%的种质资源28份,低于40%的种质资源23份。获得了单性结实性相对稳定种质4份,为黄瓜单性结实性遗传与育种奠定了物质基础。2黄瓜超级子房生长发育规律及其内源激素的研究春季日光温室条件下,对‘6457’栽培群体中自然发生的超级子房生长发育规律及其内源激素研究结果表明,开花当天超级子房长度在9cm以上,平均长度为14.4cm,占74.6%,典型超级子房长度为13.0～17.0cm；开花当天正常子房长度在9cm以下,平均长度为5.8cm,占25.4%,典型正常子房长度为5.0～7.0cm。开花当天超级子房长度是正常子房长度的3倍左右,超级子房株率为64%。超级子房与正常子房(果实)发育速度和雌蕊发育进程基本一致,但比正常子房延迟开花4～5d。超级子房形成的生理机制可能与高水平的内源GA3含量以及较高的ZT／ABA和GA3／ABA有关。不同浓度的TDZ(10mg／L、5mg／L、2.5mg／L、1.25mg／L、0 mg／L)处理均能有效诱导黄瓜超级子房的发生。其中,2.5mg／L的TDZ处理效果最佳,使开花当天平均子房长度为11.2cm,比对照延迟开花4-5d,超级子房百分率达75%,且有效促进了果实的快速发育,处理后第11d果实长度为23.6cm,远大于对照(13.2cm)。3黄瓜单性结实性遗传分析对单性结实雌性系‘6401’与非单性结实自交系‘6429’、‘6426’杂交组合6世代群体的单性结实性遗传分析表明,在不同遗传背景下,全雌黄瓜单性结实性均表现为不完全隐性遗传,受2对加性-显性-上位性主基因+加性-显性多基因控制(E-1-1模型)。两组合第一主基因显性效应、主基因显性×显性互作效应以及多基因效应较大。B1、B2、F2主基因遗传率分别为0.6%～51.1%、59.6%～75.4%、41.3%～71.4%,相应的多基因遗传率分别为0.2%～19.9%、0.0%～12.7%、3.2%～35.5%。对雌雄同株黄瓜单性结实自交系‘6457’与非单性结实自交系‘6429’、‘6426’构建的6个世代遗传分析表明,不同遗传背景和季节下,雌雄同株黄瓜单性结实性均受2对主基因+多基因控制(E-1-0,E-1-2)。不同季节F1的遗传倾向不同,两对主基因的加性效应值均较大。B1、B2、F2主基因遗传率分别为72.2%～88.8%、52.5%～93.1%、88.6%～95.4%,相应的多基因遗传率分别为0.0%～11.2%、0.0%～43.1%、0.0%～1.5%。以单性结实自交系‘6401’、‘6457’与非单性结实自交系‘6429’杂交组合的4世代联合分析结果表明,同一遗传背景下,全雌黄瓜和雌雄同株黄瓜单性结实性均受2对不完全隐性主基因+多基因控制。全雌黄瓜单性结实性遗传受2对加性-显性-上位性主基因+加性-显性-上位性多基因控制(E-1-0模型),F2的主基因的遗传率为83.5%；雌雄同株黄瓜单性结实性遗传受2对加性-显性-上位性主基因+加性-显性多基因控制(E-1-1模型),F2的主基因的遗传率为42.1%。基于强单性结实黄瓜自交系‘6457’与非单性结实自交系‘6429’构建的4世代群体,对南京江宁和河北昌黎两地黄瓜单性结实性遗传进行了比较研究。结果表明,不同生态环境下,雌雄同株黄瓜单性结实性遗传均符合E-1-1模型,受2对加性-显性-上位性主基因+加性-显性多基因控制,存在基因型与环境互作效应。不同环境条件下F1的遗传倾向和遗传参数不同,F2的主基因遗传率为42.1%～97.5%。强单性结实性黄瓜品种选育以双亲均为强单性结实为宜,常规杂交育种早期世代选择有效。4黄瓜单性结实性相关的分子标记研究基于雌雄同株黄瓜单性结实自交系‘6457’和非单性结实自交系‘6429’为亲本构建的F2分离群体,采用BSA方法筛选与黄瓜单性结实性连锁的AFLP分子标记。结果表明,引物E41／M47在非单性结实池中扩增出一条分子量约为325bp的特异条带。经F2单株验证,该特异条带能在大多数非单性结实单株中稳定出现。用MapMaker3.0软件进行连锁分析表明,该特异条带与黄瓜非单性结实基因存在连锁关系,遗传距离为9.7cM,命名为AGG／CAA325。基于同一群体,获得了与雌雄同株黄瓜单性结实性连锁的ISSR分子标记,其遗传距离为27.5cM,命名为I75580；此外,还获得了与雌雄同株黄瓜单性结实性相关的SSR特异片段CSWTA06350。以黄瓜单性结实雌性系‘6401’和非单性结实自交系‘6429’为亲本构建的F2分离群体,用BSA方法获得了与全雌黄瓜单性结实性连锁的ISSR分子标记,遗传距离为22.5cM,命名为I61470。更多还原

【Abstract】 Cucumber (Cucumis sativus L.) is an important vegetable in China, parthenocarpy is an important yield-related economic trait in cucumber, and it is one of the breeding objective traits of cucumber varieties special for protected cultivation. To evaluate correctly the parthenocarpy of germlasm, to realize the mechanism of physiology and inheritance of the parthenocarpy and to screen the molecular markers related to the parthenocarpy is the basis of genetic improvement in cucumber. In this disseration, based on the evaluation of parthenocarpy of 75 cucumber germplasm under different condition, using mixed major gene plus polygenes genetic models of quantitative traits, a joint analysis of multi-generations from crossing a highly parthenocarpic gynoecious line’6401’and a monoecious lines’6457’with two non-parthenocarpic inbred lines’6429’and’6426’was carried out to investigate the inheritance of the parthenocarpy in cucumber. The development and endogenous hormone of super ovaries and molecular markers of related to parthenocarpy were studied for genetic improvement to the parthenocarpy in cucumber. The main results are as following:1 Evaluation of parthenocarpy in cucumber germplasmParthenocarpy of 75 cucumber germplasm and cultivars was evaluated under greenhouse condition in spring season. The results showed that the parthenocarpy percentage was continuously distributed from 0 to 100%, and there were significant differences on parthenocarpy among accessions. While 40 accessions were found strongly parthenocarpic (53.3%),24 were medium (32%) and 11 were weakly parthenocarpic (14.7%).20 out of the 24 cultivars were found as strong parthenocarpic (83.3%), and the rest was mid-parthenocarpic. The degree of parthenocarpy was expressed by the fruit set capability,. The cucumber plants get stronger parthenocarpic with the nodes increase and the best evaluation should be done under 20th nodes. Parthenocarpy of 55 germplasms was evaluated in spring under the plastic tunnel in Najing. There were 4 accessions which parthenocarpic fruit set were more than 70%, while 28 accessions with 40%-70%, and 23 accessions with less than 40%. The parthenocarpy of 4 accessions performed relatively unvariable, these germplasms are elite for the purpose of breeding and genetic analysis.2 Study on development and endogenous hormone of super ovaries in cucumberThe development and endogenous hormone levels in the super ovaries of the strongly parthenocarpic inbred line’6457’under greenhouse in spring season were studied. The results showed that the length of the super ovaries at anthesis was much more than 9cm, accounted for 74.6%, the average length was 14.4cm, and concentrated at 13.0～17.0cm typically; While that of the normal ovaries is less than 9cm, accounted for 25.4%, the average length was 5.8cm, and concentrated at 5.0～7.0cm typically. The length of the super ovaries at anthesis was 3 times as that of the normal ovaries. The percentage of the plants with super ovary was 64%. The development of the pistil and fruit with super ovary present a good similarity with that of the normal, but the blooming time of the super ovary was four or five days later than that of the normal. The physiological mechanism of the super ovaries was concerned with the higher GA3 content as well as the ZT/ABA and GA3 /ABA.The super ovary could be induced by all kinds of concentrations of TDZ (10mg/L, 5mg/L,2.5mg/L,1.25mg/L, Omg/L). The best concentration for super ovary was 2.5mg/L. The blooming time of the treatment was four or five days later than that of the control. The average length of the ovary at anthesis was 11.2cm, and the super ovary percentage was 75%. While the treatment of 2.5mg/L TDZ could accelerate the fruit development rapidly. The average length of the fruit was 23.6cm at the 11 days after treatment, while that of the control was only 13.2cm.3 Inheritance of parthenocarpy in cucumberA joint analysis of six-generations from crossing a highly parthenocarpic gynoecious line’6401’with two non-parthenocarpic inbred lines’6429’and’6426’was carried out to investigate the inheritance of the parthenocarpy in cucumber. Results showed that the inheritance of gynoecious parthenocarpy was fitted the same genetic model in different genetic backgrounds. Parthenocarpy is incompletely recessive and controlled by two additive-dominant-epistatic major genes and additive-dominant polygenes (E-1-1 model) in the two crosses. Dominant effect of the first major gene and dominant×dominant interaction between the two major genes as well as polygene effects were higher. The major gene heritabilities of B1, B2, and F2 were 0.6%～51.1%,59.6%～75.4%, and 41.3%～71.4% respectively. While the corresponding polygene heritabilities were 0.2%～19.9%, 0.0%～12.7%, and 3.2%～35.5% respectively.A joint analysis of six-generations from crossing a highly parthenocarpic monoecious lines’6457’with two non-parthenocarpic inbred lines’6429’and’6426’was carried out to investigate the inheritance of the parthenocarpy in cucumber in different backgrounds and seasons. The results showed that inheritance of parthenocarpy was controlled by two major genes and polygenes. The additive effects of the two major genes were great. The major gene heritabilities of B1, B2, and F2 were 72.2%～88.8%,52.5%～93.1%, and 88.6%～95.4% respectively. While the corresponding polygene heritabilities were 0.0%～11.2%, 0.0%～43.1%, and 0.0%～1.5% respectively.A joint analysis of four-generations from crossing a highly parthenocarpic gynoecious line’6401’and monoecious line’6457’with a non-parthenocarpic inbred line’6429’was carried out. The results showed that under the same genetic backgroud, inheritance of parthenocarpy in monoecious and gynoecious cucumber was controlled by two major genes and polygenes. The inheritance of parthenocarpy in gynoecious cucumber was controlled by two additive-dominant-epistatic major genes and additive-dominant-epistatic polygenes (E-1-0 model), the major gene heritability of F2 was 83.5%. While the inheritance of parthenocarpy in monoecious cucumber was controlled by two additive-dominant-epistatic major genes and additive-dominant polygenes (E-1-1 model), the major gene heritability of F2 was 42.1%.A joint analysis of four-generations from crossing two monoecious inbred lines were carried out to study inheritance of parthenocarpy in cucumber at Jiangning (Nanjing) and Changli (Hebei). The results showed that the interaction between genotype and environment was detected, and the inheritance of parthenocarpy in monoecious cucumber was fitted E-1-1 model, and controlled by two additive-dominant-epistatic major genes and additive-dominant polygenes under different eco-environments. While the F1 tendency and genetic parameters of the parthenocarpy were different, and the major gene heritabilities of F2 were 42.1%～97.5%.Parents that both are highly parthenocarpic should be chosen in breeding programs for cucumber with highly parthenocarpy. Selection of parthenocarpy can be carried out in the earlier generations of conventional crossing breeding.4 Studies on the molecular markers linked to parthenocarpy in cucurmberExtreme parthenocarpy and extreme non-parthenocarpy DNA pools, which came from F2 population between a highly parthenocarpic monoecious line ’6457’ and non-parthenocarpic line ’6429’, were developed separately according to the bulked segregant analysis (BSA). AFLP technique was employed to sreen molecular markers linked to the parthenocarpy. In extreme non-parthenocarpy DNA pool, a 325bp specific fragment was amplified with the primer E41/M47. This marker was testified with individual DNA of the F2 population. Linkage analysis using the software of MapMaker 3.0 indicated its genetic distance to the non-parthenocarpy was 9.7 cM, and this AFLP marker was designed as AGG/CAA325.In extreme parthenocarpy DNA pools from the same population, a 580bp specific fragment was amplified with the ISSR primer I-75, its genetic distance to the parthenocarpy was 27.5 cM, and this ISSR marker was designed as I75580. In addition, an SSR specific fragment CSWTA06350 was related to parthenocarpy in monoecious cucumber.Extreme parthenocarpy and extreme non-parthenocarpy DNA pools, which came from F2 population between a highly parthenocarpic gynoecious line’6401’and non-parthenocarpic line’6429’, were developed separately according to the bulked segregant analysis (BSA). In extreme parthenocarpy DNA pool, a 580bp specific fragment was amplified with the ISSR primerⅠ-61, its genetic distance to the parthenocarpy was 22.5 cM, and this ISSR marker was designed asI6147o.更多还原