【作者】 冯雪梅；

【导师】 沈法富；

【作者基本信息】 山东农业大学 ， 作物遗传育种， 2010， 硕士

【摘要】 棉花具有明显的杂种优势,应用核雄性不育系生产杂交种是杂种优势利用的有效途径之一。选育综合性状好、配合力效应高的核雄性不育系是配制高优势杂种的前提。本研究以利用辐射诱变和回交培育的“21A”雄性不育系为材料,对该不育系的花器官形态、花粉育性、不育基因的遗传及等位性、杂种配合力和miRNA差异表达进行了分析,主要结果如下:(1)通过比较不育株和可育株花器官形态发现,不育株花较小,无花粉或有花粉但无生活力,经碘化钾染色,多数不着色或着色较浅,表明不育株花粉完全败育。(2)对“21A”不育系进行了遗传分析。“21A”雄性不育系与鲁棉研21号杂交的F1可育,其自交F2中可育株和不育株分离比例为3:1,不育株和可育株兄妹交,其后代Ft可育株和不育株分离比例为1:1,表明该不育系为单隐性核雄性不育系基因控制。(3)对“21A”单隐性核雄性不育系基因进行了等位性测验。用“21A”核雄性不育系与不同棉花品种配制的杂交种,分别与目前已知的棉花单隐性核雄性不育系洞A(msc1)、1355A(msc2)、阆A(msc3)、81A(msc7)的不育株授粉,结果发现其后代均为可育株,这表明“21A”单隐性核不育基因与上述4个陆地棉单隐性核雄性不育基因彼此是非等位基因,因此,可以把它作为一个新的隐性核雄性不育基因。(4)采用NCⅡ遗传交配设计,分别用“21A”不育系和鲁棉研21号作母本,5个常规棉品种作父本,配制杂交组合,对10个组合的F1产量和品质性状的竞争优势和配合力进行分析,结果表明,该不育系杂种在子棉产量、皮棉产量和伸长率等性状上优势明显;各性状的一般配合力高,子指的GCA表现尤为突出,易于筛选高优势的杂交组合。(5)提取不育株和可育株三个时期的花蕾RNA,分别用cy3和cy5标记,混合均匀后与三张miRNAs芯片上的探针进行杂交。结果表明有8个miRNAs在不育株和可育株花蕾的三个发育时期差异表达显著,它们可能与花粉败育有关。通过计算机预测了这8个差异表达miRNAs的22个靶基因,其中,miR166和miR156/miR157分别靶向棉花编码ATHE-15、SPL3及RNA解旋酶的基因。更多还原

【Abstract】 The heterosis in cotton is very obvious, especially in increasing the yield potential. And utilization of male sterility in heterosis has a good developmental prospect. In order to get good hybrid seeds, the premise is that breed new male sterile line which has better traits and general combining ability (GCA).In this study, the male sterility of“21A”has been observed successfully by induced mutation breeding and back cross breeding. Flower Morphologies of“21A”plants, pollen is sterile or fertile, genetic and allelic tests,analyzation competitive heterosis and combining ability and microRNA microarray were applied to“21A”.The results were as follows:(1) Morphological comparison of flower between“21A”male sterile and fertile plants was made and found that the flowers of male sterile plants were smaller than those of fertile plants.There was no pollen or a little in the anthers of male sterile plants .Stain anthers using potassium iodide of male sterile ones and the results showed that they were not be stained or light staining.The results proved that the pollen of male sterile plants was sterile completely.(2) Genetic analysis for“21A”male-sterile line were made. The ratio between NO. of fertile and sterile plants was 3:1 and 1:1 in the F2 and Ft generations respectively. Segregation results showed that the male sterility in“21A”was controlled by a pair of single-recessive gene.(3) Allelic tests for“21A”male-sterile line were made and the results indicated that the male sterility in“21A”was none-allelic to msc1, msc2, msc3 and msc7 discovered in P. R. China till now. It is proposed that 21A male-sterile gene symbol be tentatively named a new one.(4) Crosses were made by NCⅡ, using“21A”male sterility line and Lumianyan21 as male parents respectively and five normal cultivars as female parents, to analyze competitive heterosis and combining ability of F1 hybrids. The results indicated that“21A”hybrid cottons showed obvious heterosis in seed-lint yield, lint yield and elongation percentage and better general combining ability (GCA) , especially in seed index. It is easy to observe better cross combinations and product hybrid seeds using“21A”male sterile line.(5) Total RNA at different stages, i.e., sporogenous cell stage, pollen mother cell (PMC) stage, and pollen grain stage, were isolated using Norgen kit. Microarrays were hybridized with Cy3 and Cy5 fluorescence-labeled probe pairs of sterile pants plus fertile plants. The results showed that 8 new cotton miRNAs which were expressed differently between sterile and fertle plants at diffent stages of buds. And 22 target genes were predicted which maybe related to pollen abortion. MiR166 and miR156/157 could target 3 target genes respectively, ATHE-15, SPL3 and RNA helicase.更多还原