龙特甫A对杂种抽穗期的遗传效应

在沙县自然条件下，用珍汕97A、龙特甫A分别与3个含潜在感光因子的恢复系明恢70、明恢73、3550和1个感光的恢复系红田谷配制8个杂交组合，调查其F1抽穗期表现，F2抽穗期分离情况，结果表明，珍汕97A配制的4个杂交组合，F1均表现为感光，汕优70，汕优73F2代中不感光株与感光株的分离比例为2：1、37：27，表现为2对、3对基因的差异。龙特甫A与含潜在感光因子的不感光恢复系配组F1均表现不感光。特优70F2中无感光株出现，迟熟株与早熟株的比例为3：1，表现抽穗期为1对基因控制，而特优3550F2中抽穗期为连续变异，抽穗期为多基因控制的数量性状遗传。龙特南A与感光的恢复系配组后代表现为弱磁光，F2分离为9感光株：7不感光株，表现为2对感光基因的差异，龙特甫A有抑制感光的基因存在。     

水稻抽穗期QTL及其与产量性状遗传控制的关系

 产量和抽穗期是评价水稻品种应用价值的基本性状。水稻QTL分析已经历了从初定位到基因克隆的发展过程,并以抽穗期和产量性状最受重视。总结了亚洲栽培稻抽穗期QTL的基因组分布,分析了这些QTL与产量性状遗传控制的关系,为进一步筛选和鉴定具有较高育种应用潜力的水稻抽穗期QTL和产量性状QTL提供参考。     

两个中籼水稻品种的抽穗期遗传

南京11和武进香籼均为中籼稻品种,F₁生育期超(晚)亲优势极强。通过对F₁、F₂、BC₁、BC₂等世代在自然日长或短日照处理条件下抽穗期的考察,证明杂种超亲迟熟与双亲的3个感光性主基因位点的分化有关,三者以互补方式决定植株的强感光性;两亲本分别含有2对和1对互补基因,根据系谱分析双亲的互补基因分别来自我国华南或东南亚的水稻品种。     

水稻抽穗期遗传与分子调控机理研究进展

 抽穗期是与水稻产量相关的重要农艺性状之一。介绍了水稻抽穗期的遗传方式和生长发育特性;总结了618个定位的抽穗期QTL和以Hd1、Hd3a、Ghd7、Ehd1等为代表的控制水稻抽穗期的重要功能基因,并初步形成了水稻抽穗期的调控网络。还进一步讨论了水稻抽穗期研究中所面临的问题以及其在生产实践中的应用前景。     

水稻不同生育阶段营养条件与抽穗期的关系

通过2 a多点试验,研究了秧苗生长状态、本田营养条件(密度、肥料)及不同生育阶段营养条件变化对水稻抽穗期的影响.结果表明,移栽密度较大,或施肥较足,或秧苗生长状态较好,均能提早抽穗,其效应大小取决于营养环境的变化程度,秧苗期比本田期的效应更大.不同生育阶段营养条件的变化对抽穗期的影响不同,叶龄指数45%左右是水稻生长发育的一个转折期,在此之前抽穗期对营养条件的反应更敏感,且促进生长与促进发育一致,此后则对营养的敏感性降低,且促进生长不一定能促进发育,有时反而推迟发育.认为将感营养性(受营养生态影响而改变发育速度的特性)与感温性、感光性、基本营养生长期并列("三性一期")描述水稻的生育特性更为合理,制种中更应重视亲本的感营养性.     

小麦抽穗期的遗传调控研究进展

抽穗期是小麦生长发育过程中的主要农艺性状之一,而春化作用和光周期反应是决定小麦抽穗期的重要因素。本文首先对小麦抽穗期遗传研究进展进行综述,对已定位到的参与春化作用和光周期反应的相关基因及其他调控抽穗期的位点进行分析,并归纳抽穗期相关基因的遗传调控网络;然后讨论了小麦抽穗期相关基因对小麦产量的影响,以期通过现代生物学技术,并结合各个学科的相关理论知识,为小麦抽穗期遗传研究提供参考信息,进而提高小麦产量。     

水稻不同节位和数量分蘖对抽穗期的影响

以汕优63为材料,研究了在盆钵栽培条件下人工去蘖形成不同节位、不同数量分蘖的处理对抽穗期的影响.结果表明,随着保留的分蘖数量减少,抽穗期逐渐延迟;分蘖早发(低节位分蘖多、高节位空位)的处理比分蘖迟发(低节位空位、高节位分蘖多)的处理抽穗期明显提早;分蘖迟发能促进高节位分蘖的发生,而分蘖早发则相反.因此,水稻分蘖不仅具有数量调节作用,还有空间及时间调节作用.     

杂交水稻亲本遗传差异及其与杂种优势关系

 以目前生产上大面积应用和新育成的16个籼型三系杂交水稻亲本为材料,根据11个主要农艺和经济性状进行主成分分析和聚类分析,以马氏距离为指标,研究了杂交水稻亲本间遗传差异的状况及其与杂种优势的关系。在16个亲本的120个遗传距离中,80%以上小于2;9个恢复系间的平均遗传距离仅为0.4793, 7个保持系间,除湘香2号B外,平均遗传距离为0.7723。说明现有杂交稻亲本间遗传差异较小,尤其是保持系内和恢复系内遗传差异更小。对亲本间遗传距离与杂种优势的相关分析表明,现有籼型三系杂交稻亲本间遗传差异与杂种优势关系不密切,而杂交稻产量的高低与双亲产量尤其是双亲产量平均值的高低密切相关。说明亲本改良在提高杂交稻产量中极为重要。此外,还对亲本改良与杂种优势的关系、杂交稻亲本改良的方法和途径以及杂交稻组合亲本选配原则进行了讨论。     

水稻抽穗期基因OsDof6功能的初步研究

【目的】以前期通过穗发育芯片筛选到一个水稻Dof家族转录因子OsDof6为研究对象,进一步探究OsDof6的表达模式与生物学功能。【方法】对OsDof6的基因、蛋白及启动子序列进行生物信息学分析,利用CRISPR/Cas9技术对该基因进行定点编辑,通过实时定量PCR和亚细胞定位技术分析该基因的表达模式。【结果】对该基因的启动子序列分析表明,该基因启动子中存在大量与光响应、激素响应及胁迫响应相关的顺式调控元件。利用CRISPR/Cas9技术获得了2种不同突变类型的功能缺失突变体9522^Dof6-3和9522^Dof6-4。对突变体T₁株系进行表型观察发现,相较于对照,两种突变体在营养生长阶段分蘖数明显降低,转入生殖生长阶段后,两种突变体的抽穗时间推迟约3 d。实时定量PCR结果显示OsDof6在水稻根、茎、叶和穗中均有不同程度的表达,在穗发育后期相对表达量明显提高;通过亚细胞定位分析发现OsDof6定位于细胞核。【结论】初步判断OsDof6基因会影响水稻分蘖数与抽穗期。     

两优2186不同播种期与产量的关系

两系杂交稻组合两优2186系福建省农科院稻麦所利用SE21S/明恢86配制而成的,于2000年3月通过福建省农作物品种审定委员会审定.为了较深入地了解该组合在福鼎的特征特性表现,明确两优2186在福鼎的最适播插期,于2004年在福鼎市布置了该组合的不同播种期的试验.     

Research on genetics of rice heading date

Heading date is one of the most important traits for rice adaptation to cultivation area and crop seasons, and it is mainly determined by photoperiod, basic vegetative growth, and temperature of cultivars. The diversity of combinations of photo-sensitive varieties and the basic vegetative, makes the heading date varied. On one hand, this supplies abundant resources for different ecotypes breeding; on the other hand, it complicates the inheritance of heading date. In recent years, transgression of late maturity has often been encountered, especially between indica and japonica subspecies, this had inhabited the use of hybrid vigor. Therefore, understanding the inheritance basis of heading date is very important for breeding practices.     

Determination of rice panicle numbers during heading by multi-angle imaging

Plant phenomics has the potential to accelerate progress in understanding gene functions and environmental responses. Progress has been made in automating high-throughput plant phenotyping. However, few studies have investigated automated rice panicle counting. This paper describes a novel method for automatically and nonintrusively determining rice panicle numbers during the full heading stage by analyzing color images of rice plants taken from multiple angles. Pot-grown rice plants were transferred via an industrial conveyer to an imaging chamber. Color images from different angles were automatically acquired as a turntable rotated the plant. The images were then analyzed and the panicle number of each plant was determined. The image analysis pipeline consisted of extracting the i2 plane from the original color image, segmenting the image, discriminating the panicles from the rest of the plant using an artificial neural network, and calculating the panicle number in the current image. The panicle number of the plant was taken as the maximum of the panicle numbers extracted from all 12 multi-angle images. A total of 105 rice plants during the full heading stage were examined to test the performance of the method. The mean absolute error of the manual and automatic count was 0.5, with 95.3% of the plants yielding absolute errors within ± 1. The method will be useful for evaluating rice panicles and will serve as an important supplementary method for high-throughput rice phenotyping.     

水稻骨干亲本育种价值分析

在介绍粳稻丰锦、辽粳5号、盐粳32、盐粳68等来源及特点的基础上,以配合力为指标,分析了这4个品种的产量性状的遗传潜势,结合系谱分析,论证了骨干亲本的育种价值,并探讨了骨干亲本的利用方式。     

Multivariate analysis of nitrogen content for rice at the heading stage using reflectance of airborne hyperspectral remote sensing

Airborne hyperspectral remote sensing was adapted to establish a general-purpose model for quantifying nitrogen content of rice plants at the heading stage using three years of data. There was a difference in dry mass and nitrogen concentration due to the difference in the accumulated daily radiation (ADR) and effective cumulative temperature (ECT). Because of these environmental differences, there was also a significant difference in nitrogen content among the three years. In the multiple linear regression (MLR) analysis, the accuracy (coefficient of determination: R², root mean square of error: RMSE and relative error: RE) of two-year models was better than that of single-year models as shown by R² ≥ 0.693, RMSE ≤ 1.405 g m⁻² and RE ≤ 9.136%. The accuracy of the three-year model was R² = 0.893, RMSE = 1.092 g m⁻² and RE = 8.550% with eight variables. When each model was verified using the other data, the range of RE for two-year models was similar or increased compared with that for single-year models. In the partial least square regression (PLSR) model for the validation, the accuracy of two-year models was also better than that of single-year models as R² ≥ 0.699, RMSE ≤ 1.611 g m⁻² and RE ≤ 13.36%. The accuracy of the three-year model was R² = 0.837, RMSE = 1.401 g m⁻² and RE = 11.23% with four latent variables. When each model was verified, the range of RE for two-year models was similar or decreased compared with that for single-year models. The similarities and differences of loading weights for each latent variable depending on hyperspectral reflectance might have affected the regression coefficients and the accuracy of each prediction model. The accuracy of the single-year MLR models was better than that of the single-year PLSR models. However, accuracy of the multi-year PLSR models was better than that of the multi-year MLR models. Therefore, PLSR model might be more suitable than MLR model to predict the nitrogen contents at the heading stage using the hyperspectral reflectance because PLSR models have more sensitive than MLR models for the inhomogeneous results. Although there were differences in the environmental variables (ADR and ECT), it is possible to establish a general-purpose prediction model for nitrogen content at the heading stage using airborne hyperspectral remote sensing.     

Genetic analyses of heading date of Japonica rice cultivars from Northeast China

Northeast regions of China (38–55°N latitude) play an important role in Japonica rice planting. Heading dates of 10 Japonica rice cultivars native to the Northeast of China were investigated and their sensitivities to photoperiod and temperature were analyzed. The results showed that these Japonica rice cultivars were insensitive to photoperiod but strongly sensitive to temperature, i.e. a high temperature can markedly shorten the heading date. Genetic analyses were conducted on these 10 cultivars using a set of heading date tester lines. All these Japonica cultivars carried a dominant early heading gene Ef-1, and most of these cultivars carried the photoperiod insensitivity allele e₁, and two types of alleles were presented at the Se-1 locus, including recessive photoperiod insensitivity gene Se-1^e and dominant strong photoperiod-sensitivity (PS) gene Se-1ⁿ. The PS of these cultivars carrying E₁ or Se-1ⁿ can be repressed or weakened by Ef-1 and the recessive allele hd2 they carried. These results provided a reasonable explanation to the adaptability of Japonica rice to the high latitude environment of the Northeast China, and could be useful for breeding new cultivars well adapted to the high latitude regions and expanding the rice cultivation range.     

Inheritance study on the stable herbicide resistance of transgenic rice

The transgene technology showed a potentiality in crop improvement such as disease and insect resistance, anti-adversity, and grain quality. The inheritance of bar gene for herbicide BASTA resistance in stable transformed rice lines was studied for an understanding of the foreign gene inheritance pattern.     

水稻抽穗结实期田间管理技术

阐述了水稻抽穗结实期对稻米品质形成的重要性。提出适时适量施用穗肥、浅水灌溉、防御低温冷害、除草灭病虫、适期收获管理等几项增产增收、提高稻米品质的田间管理技术措施。