沙田柚宜昌橙杂种育性与有性后代的培育

发布时间：2018-02-21 08:51

本文关键词： 沙田柚宜昌橙异源四倍体花粉育性减数分裂基因原位杂交(GISH)　出处：《西南大学》2017年硕士论文　论文类型：学位论文

【摘要】：柑橘(Citrus)是芸香科的热带、亚热带果树。在柑橘育种中,多倍体育种受到越来越多的重视,培育无核三倍体柑橘是重要育种目标之一,二倍体与四倍体杂交是得到三倍体的最佳方法。同时异源四倍体比同源四倍体遗传基础广泛,多用于培育新型、多抗砧木以及作为培育三倍体无核柑橘品种的亲本材料。因此本文以沙田柚宜昌橙杂种(异源四倍体CSY和异源二倍体SY)及其亲本为试验材料研究其育性同时创制新的种质资源,为柑橘育种提供了重要的候选资源。主要研究结果如下:1、对沙田柚宜昌橙杂种及其亲本的花粉活力、花粉量研究表明,与亲本沙田柚和宜昌橙相比,沙田柚宜昌橙杂种花粉活力较亲本低、花粉量少,均介于亲本之间,异源二倍体比异源四倍体育性低。在花粉原位萌发及穿柱情况观察中发现,沙田柚宜昌橙杂种花粉能够在柱头上正常萌发。胚囊观察发现沙田柚宜昌橙杂种能够形成单核胚囊和二核胚囊,甚至形成六核胚囊。沙田柚宜昌橙杂种有育性,但育性较亲本低。与异源二倍体相比,加倍后获得的异源四倍体育性得到了部分恢复。2、对沙田柚宜昌橙杂种及其亲本的花粉母细胞减数分裂过程中染色体行为观察发现,亲本减数分裂较少出现异常,而沙田柚宜昌橙杂种减数分裂过程中存在异常配对情况和异常分离现象。异源二倍体SY异常频率为21.93%,中期除二价体外,还有单价体和三价体存在,构型为1.45Ⅰ+7.45Ⅱ+0.55Ⅲ,后期和末期均出现落后染色体、不均等分裂的现象。异源四倍体CSY的异常率为30.40%,中期存在大量的多价体,频率高达40.38%,后期和末期出现落后染色体、不均等分裂、染色体桥以及微核的异常现象。GISH结果表明,异源杂种中宜昌橙的染色体组分配到子细胞中的数目是不同的,出现了不均等分离现象。这些异常现象可能是导致花粉败育和种子败育的原因之一。3、对沙田柚宜昌橙杂种及其亲本的果实种子性状进行观察发现,沙田柚宜昌橙杂种种子性状结合了亲本的性状,外种皮为乳黄色,有棱状网纹,单胚,子叶白色,呈卵圆形。果实种子总数多,且种子出现败育现象。其中CSY正常种子数为51粒,败育种子数有33粒,SY正常种子数仅为9粒,败育种子数有79粒。说明异源四倍体经染色体加倍后育性得到了部分恢复。4、对沙田柚宜昌橙杂种果实性状观察发现,果实器官巨大,有香味,可食率、出汁率以及可溶性固形物较高,但是果皮厚、味道酸、口味不佳,不可鲜食。所以沙田柚宜昌橙杂种可考虑将其作为杂交亲本,创制新的种质资源。同时由于其含酸量高,可考虑作天然的调味剂和添加剂。5、以沙田柚宜昌橙杂种为亲本获得了八个授粉组合的杂交后代,包含SY×沙田柚、CSY×沙田柚、沙田柚×SY、沙田柚×CSY、SY人工自交、CSY人工自交、CSY天然自交、CSY×奥林达夏橙的杂交后代,创制了沙田柚宜昌橙杂种和沙田柚间的多种倍性的种质资源,可为柑橘遗传和育种研究提供新材料。同时利用GISH技术分析这些杂交后代,初步研究了其染色体组成来源。
[Abstract]:Citrus is Rutaceae (Citrus) of the tropical and subtropical fruit trees. In citrus breeding, polyploid breeding has attracted more and more attention, seedless citrus is one of the most important breeding target, hybridization between diploid and tetraploid is the best way to get the triploid. At the same time than allotetraploid autotetraploid wide genetic basis, for the cultivation of new, polyclonal antibody stock and parent material for breeding seedless Triploid Citrus Cultivars. So this paper takes Yichang as the pomelo orange hybrid (allotetraploid CSY and allodiploid SY) and their parents as experimental materials to study the fertility and creating new germplasm resources and provides important candidate resources for citrus breeding. The main results are as follows: 1. Pollen viability the Yichang orange pomelo hybrids and their parents, on the amount of pollen showed that compared with the parent pomelo and Yichang orange, pomelo Yichang orange miscellaneous flowers The activity is low pollen parent powder, less, were between parents, allodiploid than heterologous four times sports is lower. In germination and pollen found through column observation in situ, Yichang pomelo orange hybrid pollen can germinate on the stigma. The embryo sac observed Shatinyu Yichang orange hybrid can form mononuclear embryo sac and two nuclear the embryo sac, and even the formation of six nuclear embryo sac. Shatian Yichang orange hybrids fertility, but the fertility were low. Compared with the allodiploid, double obtained after four times of sports heterologous recovered partially.2, PMC of Yichang orange pomelo hybrids and their parents split chromosome behavior during the observation, parents meiosis is less abnormal, abnormal pairing and anomaly separation phenomenon and Yichang pomelo orange hybrid meiosis. Allodiploid SY abnormal frequency was 21.93%, in addition to the middle Two price in vitro, and univalent and trivalent, configuration is 1.45 I +7.45 II +0.55 III, late and end are lagging chromosome unequal division phenomenon. The abnormal rate of tetraploid was 30.40% CSY, mid-term multivalent large, high frequency of 40.38%, and later the end of lagging chromosomes do not equal division,.GISH abnormal chromosomes and micronuclei bridge. The results showed that the different number of chromosomes in a cell sub group assignment in Yichang orange to heterologous hybrids, the unequal separation phenomenon. These phenomena may be caused by pollen abortion and seed abortion is one of the causes of.3, observed for fruit seeds characters of Yichang orange pomelo hybrids and their parents, Shatian Yichang orange hybrid seed traits with parent traits, exocarp cream, prismatic reticulate, single embryo, Ye Bai color, oval. The total number of fruits and seeds, and the seeds appeared abortive phenomenon. Which CSY normal seed number was 51 grains, abortive seed number 33, SY normal seed number only 9 grain, abortive seed number has 79 grains. Tetraploid after chromosome doubling of fertility has been partially restored.4, on the Yichang hybrid orange fruit traits observed, fruit gigantic organs, flavor, edible rate, juice rate and soluble solids content is higher, but the thick skin, taste sour, bad taste, not fresh. So Yichang orange pomelo hybrids can be considered to be as hybrid parents, creating new germplasm resources. At the same time the content is high, may be considered as a natural flavoring agent and additive.5 in pomelo hybrids as parents Yichang orange won eight pollination's offspring, including SY * * CSY pomelo, pomelo, pomelo pomelo * * SY, CSY, SY artificial selfing, CSY artificial self pollination CSY, natural selfing progeny CSY * Valencia orange, created a variety of ploidy germplasm resources in Yichang and the orange pomelo hybrids, can provide new materials for citrus genetic and breeding research. At the same time, the use of GISH technology to analyze these hybrids, studied its chromosomes.

【学位授予单位】：西南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S666

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