33份杂交稻亲本的SSR指纹图谱构建及遗传相似性分析

选用分布在12条染色体上84对SSR引物,对6个粳型和4个籼型核质互作雄性不育系、14个籼型和9个粳型父本,共33份杂交稻亲本材料进行遗传相似性分析,并建立SSR指纹图谱数据库。结果表明：在33份材料中能够扩增出多态性的引物有54对,占所用引物的64.3%;33份材料间遗传相似系数变异范围为0.429~0.988,在遗传相似系数0.65处,33份材料被聚为籼、粳2个大类群;利用14对引物能将33份材料区分,引物RM264能将‘Ⅱ-32A’、‘协青早A’、‘冈46A’和‘K17A’4个籼型不育系与籼型恢复系区分开,引物RM432能区别5个粳型不育系与粳型可育品种,引物RM6、RM13、RM16、RM240、RM247和RM248均能鉴别籼、粳亚种。利用这6对引物的共显性标记可以鉴别籼粳亚种间杂交组合。

应用分子标记辅助选择培育抗稻瘟病杂交稻亲本

多性状的分子标记辅助选择具有重要的育种应用价值。研究先应用与水稻抗稻瘟病基因Pi25紧密连锁的分子标记对394个重组自交系进行筛选,再应用育性恢复基因连锁标记检测中选株系,获得20份候选恢复系和27份候选保持系。经田间接种稻瘟病菌、考查测交F1育性,表明利用该研究策略可以同步对多个性状进行选择,提高杂交稻亲本选育的效率。

新质源CMS-FA杂交稻系统的亲本资源筛选

用新质源雄性不育系金农1A(CMS-FA)作母本,分别与来自10个国家和国内13个省份的220个水稻品种组配成杂交种,考察F1代的花粉染色率、套袋结实率和自然结实率。在F1代中,当这3项育性指标均≤10%时,显示父本品种具有雄性不育保持能力,因而将其划分为保持系资源;当3项育性指标均≥80%时,显示父本品种具有雄性不育恢复能力,将其划分为恢复系资源;此外的其他父本品种,即3项育性指标中任何一项指标>10%或<80%,既不能作为保持系,也不能作为恢复系,被划分为非杂交稻亲本资源。在220个水稻品种中,可作为金农1A保持系的有122个,占55.5%;未发现恢复系亲本;非杂交稻亲本品种有98个,占44.5%。CMS-FA型的杂交稻亲本资源利用率为55.5%。对照野败型不育系珍汕97A(CMS-WA)的保持系亲本品种有44个,占20.0%;恢复系亲本品种42个,占19.1%;非杂交稻亲本品种134个,占60.9%。CMS-WA型的杂交稻亲本资源利用率为39.1%。CMS-FA系统比CMS-WA系统的亲本稻种资源利用率高16.4个百分点,尤其是保持系资源利用率高35.5个百分点(近1.8倍)。国外品种的育性普遍低于国内品种。

杂交水稻主要亲本材料的垩白性状及其胚乳结构电镜扫描

【研究目的】针对杂交稻米品质问题,研究杂交稻亲本垩白形成与胚乳细胞形态结构和发育以及与淀粉粒之间的关系,为进一步研究杂交稻米高垩白形成机理奠定基础;【方法】对几个应用面积较大的杂交稻主要亲本和两个米质对照品种,按GB/T17891-1999方法调查其垩白性状,对其米粒胚乳结构和淀粉粒的采用扫描电镜观察分析;【结果】亲本材料间垩白性状差异首先表现在垩白率上,其次为垩白度,最后为垩白面积。高垩白的保持系和桂朝2号垩白主要发生在中、腹部,而相对低垩白的恢复系主要在中部,腹白少或无。垩白度与垩白率间存在明显的线性关系,与垩白面积无明显相关性。淀粉粒在米粒横断面上分布的均匀性与垩白率和垩白度有较大的相关性,分布越均匀则垩白率和垩白度越小;而长方柱状细胞层数和多少与垩白率和垩白度有一定的相关性但不明显。5个恢复系和3个保持系垩白米粒的背部淀粉粒普遍发育良好而中部较差;保持系与恢复系的差异主要表现在腹部淀粉粒的发育形态上。【结论】杂交稻保持系与恢复系的垩白发生部位有所差异,垩白形成与其淀粉粒的分布有重要关系;中、腹部淀粉粒发育异常容易产生垩白,主要受胚乳细胞生理发育规律的影响。

三系杂交稻丛广41A、B的原种提纯技术

丛广 4 1A、B原种采用“一选二圃法”提纯 ,纯度从原来的 96.5 4 %和 99.9%,提高到 99.92 %和 99.99%。

辽宁省杂交稻与其亲本氮素利用特性的差异性分析

以辽宁省具有代表性的6个杂交稻组合及其亲本为试材,研究了不同氮素水平下杂交稻组合及其亲本在产量性状及氮素吸收利用特性方面的差异。结果表明,穗数和产量对氮肥水平的变化最为敏感,收获指数和千粒重敏感程度较小。在氮素吸收利用特性中,氮吸收力最为敏感,氮收获指数和氮农学利用率对氮肥的敏感度较低。和父母本相比,杂交稻的植株含氮量较低,氮吸收力、氮收获指数、氮生理利用率、氮农学利用率和氮吸收利用效率较高,特别是在较低的氮肥水平下表现更为明显。此外,杂交组合及亲本与氮吸收利用有关的氮生理利用率与植株含氮量对氮肥敏感度之间的相关性均达到极显著水平,从而可以根据中氮水平下亲本的植株含氮量对施氮量增加的反应来推测杂交稻氮生理利用率的情况。

水稻诱变糯质基因回复突变的研究

以杂交稻亲本胚乳糯质基因突变体南恢175wxR、湘恢288wxR、II-32wxB、明恢86wxR、蜀恢527wxR、明恢63wxR、龙特浦wxB以及D62wxB为材料,肉眼鉴定其自交后代胚乳性质,结果发现诱变糯质基因wx发生回复突变(即胚乳性质由糯质回复突变为非糯质),回复突变频率为0～6.34×10-5,平均为3.74×10-5.

Studies on Endogenous Hormones and Nutritional Physiology Related to the Premature Senescence of Super-hybrid Rice Liangyoupeijiu and Its Parents at Late Growth Stage

The amount of root bleeding sap, contents of chlorophyl , nutrients and hormones in flag leaves of a super-hybrid rice cultivar Liangyoupeijiu （LYPJ） and its parents 9311 and Pei’ai 64S after heading were measured in this study. The re-sults revealed that compared with 9311, the chlorophyl content of LYPJ reduced more quickly after heading, and then kept at a lower level, which was an obvious characteristic of premature senescence. The other physiological indices of LYPJ af-ter heading except abscisic acid （ABA） content in leaf and root also maintained at a lower level than 9311, while al the physiological indices of the sterile line Pei＇ai 64S were lower than LYPJ. So it was speculated that the early-aging characteristic of LYPJ may be inherited from Pei’ai 64S. Al the leaf and root early-aging traits reduced for LYPJ and its parent lines after heading, their leaf and root aged grad-ual y, which indicated that the above-ground （leaf） and under-ground （root） parts cor-related to each other closely, but there was not absolute correlations between them judged from the data.

Analysis on Genetic Differences between Parents of Two-line Medium Indica Hybrid Rice by SSR Markers

The genetic diversity of 50 parents or improved lines of two-line medium Indica hybrid rice were analyzed based on 48 pairs of SSR markers. The results showed that the clustering results were highly accordant with the parental pedigree information of the tested materials. The male sterile lines and the restoring lines were clustered into 2 distinct groups （Ⅰ and Ⅱ）, respectively. There were no significant difference in intra-group average genetic distances （GD） between the 2 groups. Most of the male sterile lines from Hunan Longping High-tech Seed Science Research Institute Co., Ltd. were grouped into a single subgroup （Ⅰ-4） under the male sterile group with the largest average GD compared with the rest male sterile subgroups. Huazhan derived lines and Guangzhou inbred lines were founded to be independent of 9311 and its derivatives or closely-related lines. Meanwhile, they have obviously been differentiated into 2 subgroups （Ⅱ-2 and Ⅱ-3）. The lines derived from Huazhan （or genetic closely related lines） showed a genetic homogenization phenomenon. Therefore, the Huazhan-derived lines should be further improved by the utilization of germplasms with good quality, high resistance and wide adaptability from Southern China to widen the GD between Huazhan derived lines and the male sterile subgroup developed by Hunan Longping High-tech Seed Science Research Institute Co., Ltd., so as to further promote the heterosis level between the groups.