外源磷处理对水稻籽粒植酸含量及相关代谢基因表达的影响

利用水稻穗离体培养方法,对不同外源磷浓度下水稻籽粒植酸等磷化物含量的差异及其植酸代谢相关功能基因在灌浆过程中的表达特征进行了探讨。结果表明,水稻籽粒中的植酸、无机磷和总磷含量随外源磷处理浓度上升呈增加趋势,但磷处理对千粒重和单位籽粒中植酸积累量的影响因磷浓度水平而异,高磷处理会导致水稻千粒重和籽粒植酸积累绝对量的显著降低;外源磷处理浓度的上升,不仅会引起水稻籽粒中锌和铁元素含量的显著降低,而且会导致锌、铁营养的生物有效性下降;外源磷处理对水稻籽粒植酸含量的影响与不同磷处理下RINO1基因的相对表达量之间存在较密切关系,中磷浓度(3P)处理会诱导RINO1基因的表达,但高磷浓度(12P)会抑制RINO1基因的表达,RINO1是外源磷浓度处理对水稻籽粒植酸合成代谢过程产生调控作用的一个重要功能基因位点,而IPK2基因与水稻在不同磷浓度处理下的植酸含量变化无直接联系。     

氮、磷、锌营养对水稻籽粒植酸含量的影响及与几种矿质元素间的相关性

以协青早、秀水110及其辐射诱变获得的低植酸突变系（HIPi1和HIPj1）为材料,通过水培试验对不同氮、磷、锌浓度处理下水稻籽粒植酸含量差异及与几种矿质元素间的相关性进行了比较分析。高水平氮、磷、锌浓度处理的籽粒植酸含量较同一品种的低氮、磷、锌处理均有所降低,但在水稻生育期间,籽粒植酸含量对磷、锌处理浓度变化的敏感性,则因品种的植酸类型特征而异;氮、磷浓度增加能分别提高铁或降低铜在籽粒中的积累,但在高锌处理下,籽粒铁含量明显降低、而钾和镁的含量等却有所升高; 籽粒植酸含量一般与K、Mg、Fe、Cu 4种矿质元素含量呈正相关、与籽粒Zn含量呈负相关,但统计显著水平因品种而异。低植酸突变体籽粒中的K、Mg、Fe、Zn等含量虽略有下降,但可以通过适当的介质营养条件来调节有关矿质营养在水稻籽粒中的积累。     

小麦籽粒蛋白质和淀粉代谢及其与品质形成关系的研究进展

蛋白质和淀粉是决定小麦籽粒产量和品质的重要组成物质。本文从小麦籽粒蛋白质和淀粉组成与品质的关系、籽粒蛋白质代谢和淀粉代谢的生理基础及小麦的碳氮代谢对品质的调控等方面对国内外有关小麦品质生理的研究进展进行了综述。这些研究表明,籽粒蛋白质和淀粉组成对小麦品质有不同的影响,品质是蛋白质和淀粉综合作用的结果;小麦的碳氮代谢及其平衡作用于小麦籽粒蛋白质和淀粉的合成与积累;生态条件和栽培措施均可通过调节小麦的碳氮代谢而影响籽粒淀粉和蛋白质的合成,进一步影响小麦品质的形成。     

转基因技术改良水稻淀粉品质研究进展

淀粉是稻谷籽粒主要的营养和能量储藏形式,主要由直链淀粉和支链淀粉组成。水稻淀粉品质的改良可以利用转基因技术修饰淀粉含量与质量的变化。本文综述了转淀粉合成相关基因改良水稻淀粉品质的实际案例。     

新消息

0199冬小麦籽粒肌醇六磷酸与蛋白含量高度相关植酸(肌醇六磷酸)是籽粒磷的主要贮藏形式,据说对营养品质有负作用.因而,低植酸育种已在几种禾谷类和豆科作物上提出.然而,重要的是对植酸影响其它籽粒组份的选择效应作出预测.Victor Raboy等人进行了一些试验,定量地确定了两个冬小麦群体籽粒     

水稻籽粒不同部位植酸含量及其与稻米品质的相关性

 选用13个不同类型的水稻品种,对其籽粒不同部位植酸含量品种间差异及与稻米主要品质性状间的相关性进行了分析。结果表明,供试13个水稻品种米糠、糙米、颖壳、精米的植酸含量平均值分别为48.51、9.77、1.40和0.91 mg/g,而且不同水稻品种间籽粒不同部位的植酸含量存在极显著差异。在籽粒中,米糠中植酸积累最多,其次是精米,颖壳最少。米糠中植酸含量与糙米和颖壳中植酸含量呈极显著正相关。糙米和米糠中植酸含量与稻米蛋白质含量均呈显著的负相关,与千粒重均呈显著正相关。     

植物激素对水稻籽粒灌浆、粒质量与品质的调控作用研究进展

植物激素是植物生长发育的重要调节物质，对水稻籽粒灌浆、粒质量和品质形成具有重要调控作用。本文介绍了水稻籽粒灌浆增重特性及其与稻米品质的关系，重点综述了水稻籽粒中不同植物激素含量的变化特点及其对籽粒灌浆、粒质量和品质的调控作用及其机理的研究进展，并提出了研究存在问题及今后方向，旨在为水稻优质高产的遗传改良和栽培调控提供理论依据。     

水稻根系育种的意义与前景

 针对目前水稻育种的理论与实践中，主要考虑地上部分的形态、生理性状，而对根系这一重要的营养吸收、物质合成器官的有关性状未能开展明确的育种改良的现状，论述了开展根系育种对改良和提高水稻的品种特性，提高产量和品质的重要性、迫切性以及前景。     

小麦铁锌营养品质研究进展

"隐性饥饿",即铁、锌等微量元素缺乏症,已成为困扰我国居民的首要营养不良问题.选育高铁、锌含量、强植酸酶活性或低植酸含量的"微量营养强化型"小麦品种对于改善我国西部居民的营养状况具有重要的意义.本文主要介绍小麦铁锌营养品质的遗传改良研究进展,包括铁锌营养品质的相关化学组分(铁、锌、植酸和植酸酶)及改善小麦铁锌营养品质的遗传途径等两方面,并指出了小麦铁锌营养品质的研究方向和工作重点.     

水稻籽粒灌浆的影响因素及相关基因和蛋白研究进展

籽粒灌浆是决定水稻产量和品质的关键步骤,直接关系着水稻的结实率和千粒重。水稻籽粒灌浆受到多种因素影响,包括品种自身特性、植物激素以及环境因子等。在分子水平上,水稻灌浆也受淀粉合成与运输相关酶及基因的调控。本文综述了水稻籽粒灌浆的影响因素及其相关基因和蛋白的研究进展。     

Influence of high temperature during filling period on grain phytic acid and its relation to spikelet sterility and grain weight in non-lethal low phytic acid mutations in rice

Low phytic acid (lpa) crop is considered as an effective strategy to improve crop nutrition. However, the inferior agronomic performance of lpa crops and their environmental growth adaptation have not yet been fully understood. Three rice lpa lines and their corresponding wild-types were used to compare their differences in grain phytic acid (PA) in response to high temperature (HT) and its relation to spikelet sterility and grain weight at a controlled temperature at the filling stage. Results showed that HT caused an increase in grain PA and inorganic phosphate contents, with more substantial increase of PA content for lpa lines compared with corresponding wild-types. This increase in PA content in high temperature-ripened grains was not simply attributed to the reduction in grain weight and relatively enhanced proportion of aleurone-layer fraction to whole grains. Significant increase in PA contents was also detected in milled rice. Moreover, spikelet sterility and grain plumpness of lpa lines were more susceptible to HT stress than those of wild-types. Exogenous PA spraying with an appropriate concentration could increase grain PA content, but it had only a slight contribution to the enhancement of heat-tolerance and injury alleviation for rice exposed to stressful HT.     

Effect of nitrogen fertilizer application on grain phytic acid and protein concentrations in japonica rice and its variations with genotypes

Thirty-one japonica cultivars with contrasting agronomic traits were used and 5 nitrogen (N) fertilizer treatments of level and timing were performed to determine the effects of N application on grain phytic acid and proteins including albumin, globulin, prolamin, and glutelin. Variance analysis showed a large effect of N and a smaller effect of cultivar on grain phytic acid and proteins. With increased N level, grain phytic acid concentrations progressively reduced whereas concentrations of the 4 proteins and ratios of glutelin to total protein increased, indicating that N level has a beneficial effect on rice nutritional quality. In addition, substantial genotypic differences in response of grain phytic acid and proteins to N treatments were detected. Some cultivars such as Xiushui09, Zhendao10, and Yanjing5 exhibited more stability of grain proteins under contrasting N treatments, and the significance of this stability is discussed in regard to its use in rice quality improvement.     

水稻粒形遗传与长粒型优质粳稻育种进展

水稻粒形遗传机制和粒形育种一直是水稻品质和产量研究的重要领域。在粳稻品种选育中,对长粒形遗传种质的选择,已经成为近年来一种新的育种趋势。我们在总结粒长及其相关性状的遗传研究进展和已知粒长相关基因功能的基础上,系统地介绍了南方稻区长粒粳稻的育种历程及其选育策略。同时,对以品种嘉禾218为代表的南方长粒晚粳稻系列品种农艺性状和品质特性进行了比较,在阐明长粒粳稻优质、高产的品种特点的同时,提出长粒晚粳育种中选择粒形、兼顾株型、保产提质的选育思路。     

Genetic variation for phytic acid content in mungbean(Vigna radiata L. Wilczek)

Mungbean(Vigna radiata L. Wilczek) is a short-duration legume crop cultivated for seeds that are rich in protein and carbohydrates. Mungbeans contain phytic acid(PA), an anti-nutritional factor that is the main storage form of organic phosphorus in seeds. It is a strong inhibitor against the absorption of nutrients including iron, zinc, calcium and magnesium in monogastric animals. Genotypes with low phytic acid(lpa) in seed may show increased assimilation of nutrients and be useful in breeding lpa cultivars. The present study was conducted to identify lpa sources, genetic variation, heritability, and association with seed coat color, inorganic phosphorus(IP), and seed size in 102 mungbean genotypes including released varieties, land races, mutants, and wild species grown in two seasons: summer 2011 and rabi 2012. PA and IP in dry seeds were estimated by modified colorimetric method and Chen's modified method,respectively. PA, IP, and 100-seed weight differed significantly in the two seasons. PA content in102 genotypes ranged from 5.74 to 18.98 mg g-1and 5.85 to 20.02 mg g-1in summer 2011 and rabi 2012, respectively. High heritability was found for PA(0.87 and 0.86) and seed size(0.82 and0.83) but low heritability for IP(0.61 and 0.60). A negative correlation was found between PA and seed size(r =-0.183 and-0.267). Yellow and green seed coat genotypes contained significantly less PA than black seed coat genotypes. Cluster analysis revealed the distinctness of wild species, land races and cultivated varieties on the basis of PA content. The genotypes YBSM(6.001 mg g-1) and JL-781(6.179 mg g-1) showed lowest PA. These lpa sources can be used to develop high-yielding mungbean cultivars with low phytic acid.     

利用贝叶斯法进行水稻籽粒植酸含量性状的QTL定位及互作分析

 利用水稻植酸含量差异较大的品种中花11(粳型)和LPA（籼型）为亲本杂交获得F2群体的172个单株,构建了含126个SSR和4个STS标记的遗传连锁图谱,利用贝叶斯（Bayesian）法对水稻籽粒植酸含量性状进行了主效应QTL定位和上位性互作分析。共检测到 3 个与水稻籽粒植酸含量性状有关的主效QTL,分布在第3、5和6 染色体的相应区间内,表型贡献率分别为538%、802%和462%,降低籽粒植酸含量的等位基因均来自亲本LPA。检测到10对上位性互作影响籽粒植酸含量, 分布于水稻第1、3、5、6、11染色体上,互作效应值为169～518,其表型变异的解释率为867%～2473%。     

我国江浙地区粳稻品种间的植酸与蛋白质组分差异及其相关性

选用我国江浙地区近期育成的晚粳稻品种（系）29个,对它们在浙江杭州相同栽培条件下籽粒中的植酸、蛋白质含量与其组分差异及其相关性进行了分析。供试29个品种(系)植酸含量的平均值为0.868%,变化幅度为0.699%~1034%,其中秀水系列品种的植酸含量一般较低,而武育粳系列和淮字系列品种（系）的植酸含量则相对较高;供试29个品种材料总蛋白质含量的平均值为8.722%,其含量大致呈正态分布。在4种蛋白质组分中,谷蛋白、球蛋白和清蛋白在品种间的变异系数较大,而醇溶蛋白则相对较小,且在分布频率上也表现出品种类型间的差异特征;除谷蛋白与总蛋白质之间存在着极显著的正相关外,供试29个品种(系)的植酸含量与蛋白质含量及4种蛋白质组分含量间并无密切的关系。     

Distribution of phytic acid and mineral elements in three indica rice (Oryza sativa L.) cultivars

Three indica rice cultivars with different grain shapes were selected to determine the milling characteristics and distribution of phytic acid (PA) and six mineral elements including magnesium (Mg), calcium (Ca), manganese (Mn), iron (Fe), zinc (Zn), and selenium (Se). Milling characteristics were quite different among the rice cultivars with different physical dimensions. Similar milling times did not necessarily result in the same degree of milling (DOM) for different rice cultivars. The concentrations of phytic acid and minerals decreased with an increased DOM. These results also showed that phytic acid and minerals except for Zn and Se were not evenly distributed and highly concentrated in the outer layer (0% < DOM < 15%) of the rice kernel. In contrast, Zn and Se seem to be relatively evenly distributed in the grain. Optimum DOM of about 14% was detected for Zhenong 7 (long and slender grain); 10% was found for Zhenong 60 (medium-grain) and 9% for Zhenong 34 (short and round grain). The information generated in this experiment could be useful to optimize milling procedures for maximum removal of phytic acid, minimum mineral losses and weight loss in indica rice cultivars with different grain shapes.     

黑龙江省水稻种质资源农艺性状与产量关系的分析

为明确黑龙江省主要水稻种质资源农艺性状与产量之间的关系,更高效的选育水稻新品种,以139份水稻种质资源为材料,采用描述性分析、相关分析、通径分析等方法对影响产量的主要农艺性状进行了试验研究。结果表明,黑龙江省水稻种质资源比较丰富,12个农艺性状的变异系数均≥11%,并且稳定性很好;分蘖株数、每穗粒数、有效穗数、剑叶宽度与产量呈正相关关系,谷粒形状与产量呈负相关关系;10个农艺性状可以归为4个主成分,其累计贡献率为68.759%。