Studies on Seed Setting Stability in Associated with Temperature for a Two-Line Hybrid Rice,Liangyoupeijiu

When being planted in wide areas in southern China (23°23' - 33°23' N, 98°35' - 120°19' E, sea level above 2.7 - 1285 m), Liangyoupeijiu (LYPJ), a two-line hybrid rice combination, showed a seed setting rate of 75.2 - 77.2%, which was lower by 4.3 - 7.5 percent point than that of an indica hybrid rice Shanyou 63 (CK), with similar values of grain yield and coefficients of variation to CK. Sowing during 5-25th of May in Nanjing (32°3' N, 118°48' E), China, LYPJ headed before 4th September, and gave a seed setting rate of 75 - 90%, and grain yield over 1 kg/m2. If the sowing date was delayed to 14 - 15th, June, its heading date would be as late as 17th - 21st September, and seed setting rate would be declined by 10 - 15% in comparison with that on a suitable sowing date. When flowering took place at an average daily temperature range of 13.7 - 28.5℃ for five days, the spikelet fertility (SF) would be increased by 1.9- 10.7%, for each increment of 1℃. The suitable (SF≥90%) and safe (SF≥75%) temperatures for flowering stage were indicated to be 26.5℃ and 22.9℃, respectively. To get a high and stable seed set in cultivating LYPJ, it was recommended that LYPJ would be planted in the areas south of 34癗, and the favorable average daily temperature during flowering stage should be at 26 - 28℃.

Mapping of three QTLs for seed setting and analysis on the candidate gene for qSS-1 in rice(Oryza sativa L.)

The lower seed setting is one of the major hindrances which face grain yield in rice. One of the main reasons to cause low spikelet fertility （seed setting） is male sterility or pollen abortion. Notably, pollen abortion has been frequently observed in advanced progenies of rice. In the present study, 149 BC2F6 individuals with significant segregation in spikelet fertility were generated from the cross between N040212 （indica） and Nipponbare （japonica） and used for primary gene mapping. Three QTLs, qSS-1, qSS-7 and qSS-9 at chromosomes 1, 7 and 9, respectively, were found to be associated with seed setting. The recombinant analysis and the physical mapping information from publicly available resources exhibited that the qSS-1, qSS-7 and qSS-9 loci were mapped to an interval of 188, 701 and 3741 kb, respectively. The seed setting responsible for QTL qSS-1 was further fine mapped to 93.5 kb by using BC2F7 population of 1 849 individuals. There are 16 possible putative genes in this 93.5 kb region. Pollen vitality tests and artificial pollination indicated that the male gamete has abnormal pollen while the female gamete was normal. These data showed that low seed setting rate relative to qSS-1 may be caused by abnormal pollen grains. These results will be useful for cloning, functional analysis of the target gene governing spikelet fertility （seed setting） and understanding the genetic bases of pollen sterility.

基于Seeds集和成对约束的半监督三支聚类集成

聚类集成使用合适的策略融合多个具有差异性的基聚类成员,能够有效提高聚类结果的稳定性、鲁棒性和准确率。当前聚类集成的研究较少利用已知的先验信息,面对复杂数据时难以刻画对象与类簇之间明确的归属关系。因此,提出一种基于Seeds集和成对约束的半监督三支聚类集成方法。首先,基于已有的标签信息提出一种新的三支标签传播算法构造基聚类成员;其次,提出一种半监督三支聚类集成框架集成基聚类成员,构造出一致性相似矩阵,并利用成对约束信息对该矩阵进行优化调整;最后,将三支谱聚类作为一致性函数对相似矩阵进行聚类,得到最终集成结果。在多个UCI真实数据集上的实验结果表明,与基于类簇的相似分区算法(CSPA)、超图分区算法(HGPA)、元类簇算法(MCLA)、标签传播算法(LPA)、Cop-Kmeans等半监督聚类集成算法相比,所提方法的归一化互信息(NMI)、调整兰德系数(ARI)和F测度在绝大多数据集上取得了最优值,获得了相对更好的聚类集成结果。

Effect of ^(211)At treating pollen and stigma on generative cells and seed setting of rice

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Distribution of Rice Grains on Panicle Axis and Its Relationship with Seed-Setting Ability in Liaoning, China

Studies were conducted with rice varieties developed in recent years in Liaoning Province of China as test materials. Results showed that the varieties tested could be divided into three types： （1） the high-yielding （HYV）, （2） the mediumyielding （MYV）, and （3） the low-yielding （LYV）. The panicle population was in the order of HYV〈 MYV 〈 LYV, while the grain number per panicle and seed-setting rate were just opposite. There was no significant difference in the 1 000-grain weight. Biomass was higher in HYV than in MYV and LYV, while the harvest index was higher in HYV and MYV than in LYV. Yield was inversely correlated with panicle population, but positively correlated with the grain number per panicle, seed-setting rate, the number of primary and secondary branch grains, seed density and harvest index. Yield was most closely linked with the grain number per panicle which was determined chiefly by the number of secondary branch grains and to a lesser degree by seed density and the number of primary branch grains. The seed-setting rate of the secondary branches was positively correlated with that of the whole panicle and yield. The peak value of primary branches for HYV, MYV and LYV was 12-14, 10-13 and 8-12, respectively. LYV had fewer secondary branch grains, while MYV and HYV had more. Such grains distributed mainly in the middle and lower parts of panicle axis for LYV and in the middle and upper parts for MYV and HYV.

Factors Influencing the Outcrossed Seed-Setting Obstacles of Photo-thermo Sensitive Genie Male Sterile Rice

Using photo-thermo sensitive genie male rice (PTGMS) Pei' ai 64S, W7415S, W6154S, N26S, Annong S, Nongken 58S, 7001S and 5088S as female parents and conventional indica lines 8258 and U89 as male parents, the factors affecting outcrossed seed-setting were analyzed. The PTGMS had obstacles in outcrossed seed setting influenced by inheritance and environment at varying degrees. Environmental temperature was regarded as the main factor that resulted in the outcrossed seed-setting obstacles. The sensitive stage was at the early stage of grain filling for outcrossed seed setting. There existed remarkable differences at the sensitivity stage, the duration of sensitive period, the sensitive level and the effective level of outcrossed seed-setting obstacles caused by environmental temperature among different PTGMS lines. Therefore, attention should be paid to outcrossed seed-setting obstacles in selection and utilization of PTGMS lines.

Molecular mechanisms controlling seed set in cereal crop species under stress and non-stress conditions

Maximizing seed yield is the ultimate breeding goal in important cereal crop species. Seed set is a key developmental stage in the process of seed formation, which determines grain number, seed mass, and realized yield potential, and can be severely affected by abiotic and biotic stresses. However, seed set can also be substantially reduced by genetic factors even under optimal fertilization conditions. The underlying molecular genetic mechanisms are still obscure. In this review, we elucidate the process of seed set of cereal crop species in detail, including development of floral structures, formation of viable gametes, double fertilization, seed development, and abortion. We discuss how genetic and non-genetic factors affect seed set in different development stages. Finally, we will propose novel strategies to study genetic mechanisms controlling seed set and exploit genetic resources to improve seed set in cereal crop species.

水稻花粉小肽锌指蛋白基因OsFLZ13功能研究

FCS样锌指蛋白(FLZ)与植物的生长发育和逆境胁迫反应相关。水稻的FLZ基因家族分析和功能研究较少。本研究利用TBtools对水稻基因组Blast,鉴定到29个OsFLZ家族基因成员,并分析了相关基因位置、基因结构、motif和启动子顺式作用元件等特征。随后,通过水稻CREP数据库研究了FLZ家族成员的全生育期组织表达模式,并发现其中的OsFLZ13基因在开花前的花药中特异高水平表达。随后β-D-葡萄糖苷酸酶(GUS)染色显示,OsFLZ13在花药发育的第8阶段开始表达,并在开花前的第14阶段表达量最高。用CRISPR/Cas9基因编辑获得的突变体植株结实率显著下降。相比野生型中花11的94%结实率,Osflz13-1和Osflz13-2的结实率分别只有44%和36%。本研究表明OsFLZ13参与花药发育以及花粉育性的调控,为进一步研究该基因及其家族基因的功能提供参考,同时对水稻雄性不育利用具有潜在的价值。

基于Seed集的半监督核聚类

提出了一种新的半监督核聚类算法——SKK-均值算法。算法利用一定数量的标记样本构成seed集,作为监督信息来初始化K-均值算法的聚类中心,引导聚类过程并约束数据划分;同时还采用了核方法把输入数据映射到高维特征空间,并用核函数来实现样本之间的距离计算。在UCI数据集上进行了数值实验,并与K-均值算法和核-K-均值算法进行了比较。

截干强度对红松结实的影响

为探讨截干强度对红松人工林结实的影响,2017年在通化县三棚林场19年生红松人工林内设置了4个截干强度(截干3轮枝、截干4轮枝、截干5轮枝,CK),2022年和2023年分别对所有处理下结实情况进行调查和分析。结果表明:截干后,红松结实株率、单株平均球果数量和产量与对照相比,均有显著增加(P<0.05),红松单个球果平均质量无明显变化。截干3轮枝时,红松结实株率最高,比CK提高了145.56%;截干5轮枝时,单株平均球果数量和产量最高,比CK分别提高了300.34%和468.04%。

一种基于Seeds集和成对约束的主动半监督聚类算法

针对半监督聚类算法中监督信息使用不充分,监督信息中信息含有量低的问题,提出一种结合主动学习的半监督聚类算法.首先结合使用数据的类别标记和成对约束信息,指导Kmeans聚类过程,设计出一种基于Seeds集和成对约束的半监督聚类算法SC-Kmeans;其次将主动学习算法引入到SC-Kmeans中,以尽量小的代价选取信息含有量更高的监督信息,提高SC-Kmeans算法的聚类精度;最后在UCI标准数据集上进行仿真实验.实验结果表明,该算法取得了较好的聚类效果,有效提高了聚类准确率.

半夏开花物候与结实特征分析

为深入理解半夏独特的开花物候特征和生殖特性,对半夏花的形态学特征、个体开花散粉习性、居群开花物候及结实特征进行了统计分析。结果表明,半夏群体开花规律呈单峰型,花期集中在5月下旬到6月下旬,花期长约58 d;半夏开花与散粉的日变化规律均呈倒单峰型,开花高峰期为7:00—11:00,而花药散粉高峰期为7:00—9:00;散粉持续时间为47.22 h,个体花期持续时间、花序开放进程、花序开花持续时间和种群花期历时分别为18、13、5.3、51.5 d;花序开放进程与花序开花持续时间分别以14 d和6 d出现的频率最高。半夏花不具虫媒、风媒花特征,传粉完全依靠花粉的自然散落,这可能是其结实率低的主要原因;进一步相关性分析发现,始花时间分别与开花率和结实率存在显著负相关关系,花期长度和开花率分别与结实率呈极显著正相关;开花率、结实率与半夏个体的块茎大小密切相关。综上,人工辅助延长半夏的花期和提高开花率有助于提高其结实率,进而提高有性繁殖效率。

不同授粉方式对油用型牡丹结实性影响的研究

为提高油用牡丹产量,探索油用牡丹理想授粉方式,选择结实性良好、生长势强且自然花期相遇的常见油用型牡丹品种,开展自交、人工授粉、自然授粉等不同方式的授粉试验,调查其坐果率、结实率、种子千粒重等结实情况和蓇葖果单角大小、质量等果荚干物质性状。结果表明,油用型牡丹存在一定自花结实性,自交处理Ⅰ没有结实,处理Ⅱ3个品种结实,处理Ⅲ全部结实,其中‘凤丹白’结实最好,为每个果角0.54粒;将参试的牡丹品种进行4×4人工定向安全双列杂交,所有组合全部结实,平均坐果率高达92%,单果角结实率达到3.87粒,结实率最高的组合为‘凤丹白×景泰蓝’,单果角结实率达到6.96粒;田间自然授粉均有结实,‘凤丹白'结实率最高,3.19粒/个;‘景泰蓝’和‘凤丹白’杂交的种子千粒重较高,达到436.89 g;蓇葖果果荚大小和质量与杂交母本关系较密切,以‘景泰蓝’为母本时表现突出;通过不同授粉方式所对应的坐果率、结实率和复果荚重等指标综合分析,从高到低依次为:人工授粉>自然授粉>自交,母本是影响杂交成功率和果荚性状的重要因素;油用牡丹生产中可通过品种合理搭配间植、相互授粉,如‘景泰蓝’和‘凤丹白’,获得更高种子产量。

玉米自交系花丝及其结实性动态研究

为探究不同玉米自交系花丝活力及其结实性动态变化规律。以玉米自交系‘浚696’、‘浚573’、‘浚503’、‘郑58’和‘昌7-2’为试验材料,测定花丝日吐丝长度和吐丝量、不同日龄花丝结实率和穗部性状等相关指标。结果显示不同自交系花丝日吐丝长度和花丝结实率均是先增后降;花丝日吐丝长度峰值在吐丝第2~3天;结实率峰值在吐丝第3~5天。花丝日吐丝量呈‘快-慢’的增长模式,吐丝第1~3天快速增长,‘浚696’花丝总量最少,‘昌7-2’花丝总量最多。授粉后第8天的小花受精率和总结实率均比第5天高,‘郑58’的小花受精率最大、‘浚696’的总结实率最高。‘浚696’、‘浚573’和‘浚503’不同日龄花丝结实率与其穗部各性状、日吐丝量和吐丝长度均呈显著或极显著正相关。研究结果为明确自交系花丝活性时间、掌握最佳授粉时期、提高自交系结实性和制种产量提供理论依据。

杂交籼稻“一种两收”头季高温热害调查及对再生稻的影响

以“一种两收”展示试验的18个杂交籼稻品种为材料,将穗形分成中大穗和中小穗,分别考查结实率,研究在自然条件下孕穗至抽穗阶段遇上中等强度高温对再生稻的影响。结果表明,品种间抗热性存在差异。在抽穗阶段遇上高温的14个品种中,深优粤禾丝苗和甬优4901的中大穗和中小穗结实率在85%以上,表现强抗热性,Y两优911的中大穗和中小穗结实率在80%以上,表现较强抗热性,其余品种的中大穗和中小穗结实率在80%以下或中大穗与中小穗结实率差距在10百分点以上,表现抗热性一般或弱;在孕穗阶段遇上高温的4个品种中,仅晶两优华占表现较强抗热性。随着高温热害的产生,头季灌浆期缩短,产量降低,再生季抽穗期提前。最后提出了桐城市再生稻减轻高温热害措施。

2023年皖西南地区水稻新品种筛选试验

为筛选适宜皖西南地区种植的水稻新品种,本研究对Y两优9826等24个水稻新品种的生育期、种植表现以及产量等进行比较,研究分析其综合表现。结果表明,各品种生育期120~138d,多数品种生育期130d,有效穗数200.1万~330.3万/hm^(2),结实率70.4%~92.8%;各品种实际产量为7851.0~12426.0 kg/hm^(2)。综合各品种生长表现,品种林两优1771、荃优879、万丰优818、玮两优8612和晶两优8612的产量较高,综合性状好,可在该地区进行推广种植。

皖西地区中籼稻新品种展示比较试验

为鉴定评价引进中籼稻新品种在皖西地区生产条件下的适应性、丰产性、稳产性和抗逆性,筛选适宜在该地区推广种植的水稻新品种。本试验在皖西地区试验点对G两优777等24个参试品种和1个对照品种丰两优四号进行展示比较试验,对比分析其生育期、产量、产量结构、农艺性状及综合抗性等方面表现。综合筛选出了适宜在皖西地区及其周边推广种植的中籼稻新品种,包括嘉丰优3号、嘉科优11、荆占2号、E两优16、全两优158、G两优777、耕香优银占、节优804、隆华丝苗、健湘丝苗、忠两优鄂晶丝苗和扬籼优953。试验结果为该地区中籼稻新品种引种及推广种植提供参考。

谷子(Setaria italica Beauv.)高异交结实雄性不育系“81-16”的柱头性状观察

谷子不育系异交结实率低严重制约着杂交种大面积应用于生产。本研究证明柱头外露程度与异交结实率呈显著正相关(r0.001=0.9597**)。山西省农业科学院经济作物研究所成功选育出谷子光敏雄性不育突变系“81-16”,其不育度为100%,异交结实率达61%。用植物形态解剖学方法证明,“81-16”雌蕊生活力强,柱头完全外露,接受花粉的有效面积大,是其异交结实率高的主要原因。本文还提出应重视母本柱头性状选育,并加强谷子杂交种制种技术研究。

基于seeds集和频繁项集挖掘的半监督聚类算法

半监督聚类在无监督学习中通过对少量监督信息的有效利用提高聚类性能。提出一种基于seeds集的半监督聚类算法,它采用Apiori算法对初始seeds集和扩大规模后seeds集的数据进行频繁项集挖掘,使得数据中存在的噪音数据和误标记数据得到净化、修正,以改善seeds集质量,提高聚类性能。该算法使用带权χ2测试这一数学模型作为分类规则度量指标,以对无标记数据进行类标签值预测。实验结果显示,所提出的结合了频繁项集挖掘和带权χ2测试的基于seeds集的半监督聚类算法不仅改善了seeds集质量,也提高了预测结果的精确度,优化了聚类性能。

黔东低山丘陵区油茶主要栽培品种配置研究

为了给油茶的科学配置提供参考依据,研究了10个黔东地区油茶主栽品种的花粉量、杂交座果率及种实性状,并对不同配置组合进行了综合评价。结果显示:(1)花粉量最大的是‘黔玉2号’,最小的是‘湘林210号’,本地品种‘黔玉’系列、‘黔碧’系列的花粉量明显大于‘长林’系列等外地引进良种;(2)88个配置组合中有68个组合可育,座果率在60%以上的配置组合有19个,其中16个是不同系列的品种组合;(3)杂交座果率与单果质量、籽粒数、籽粒重呈极显著正相关,鲜出籽率与果形指数和果皮厚呈极显著负相关;(4)以‘长林53号’为母本,贵州本地品种‘黔玉’系列、‘黔碧’系列为父本的配置组合表现最好。