稻种遗传资源多样性的开发利用及保护

由于近年来栽培稻众多改良品种的育成和大面积推广,使之在很大程度上取代了地方品种,造成栽培稻基因源的大量基因流失,导致栽培稻品种的遗传基础越来越狭窄以至不能承受新病、虫害和不利环境的袭击。同时,由于人们长期施用杀虫剂、灭菌剂和除草剂等化学农药,严重地恶化了农业生态环境。要改变这种恶性循环的局面,开发和利用稻种的遗传资源,以丰富栽培稻品种的遗传基础是非常必要的。稻种基因源包括了亚洲栽培稻、非洲栽培稻、杂草稻、稻属的野生物种以及稻族内的近缘属种,它们是栽培稻品种进一步改良所不可缺少的遗传资源。但是,由于农业生产模式的改变,社会经济和工业化水平的迅速发展和提高,稻种基因源的多样性受到了严重的影响和威胁。一些野生稻种的居群已经迅速地缩小甚至从原产地消失。因此,对稻种基因源及其多样性进行及时有效的保护,并对其进行合理的开发和利用,是保证栽培稻进一步改良和持久生产的最有效方法。     

Fate of malathion and chlorpyrifos methyl in rough rice and milling fractions before and after parboiling and cooking.

Long-grain rough rice treated with malathion (14 ppm) or chlorpyrifos methyl (Reldan) (6 ppm or 12 ppm) was sampled after 1,6, and 12 wk. Samples from each treatment were processed raw or were parboiled with fresh steeping water, once-used, and twice-used steeping water. Three replicates of rough rice and of each milling fraction were preserved, and three of milled rice were cooked. Chemical residues were measured on rough rice, hulls, brown rice, bran, milled rice, and cooked rice. Parboiling reduced residues on rough rice and hulls but tended to increase residues in the other fractions. Residues of Reldan in bran were substantially increased by parboiling. Doubling the amount of Reldan applied to rough rice approximately doubled the residues found in the milling fractions. Small amounts of the protectants survived all processing including cooking. Residues of malathion in cooked rice averaged about 0.016 ppm in nonparboiled and 0.013 ppm in parboiled rice. Residue of Reldan in cooked rice was commensurate with the amount applied to rough rice. When applied to rough rice at 6 ppm, residues of Reldan in cooked rice averaged 0.05 ppm in nonparboiled rice and 0l.065 ppm in parboiled rice. When applied to rough rice at 12 ppm, residues in cooked rice averaged .053 ppm in nonparboiled rice and 0.15 ppm in parboiled rice. Legal tolerances were not exceeded in any milling fraction. Reuse of the steeping water had little or no effect on residues.     

有色稻米Fe、Zn、Cu和Mn含量及与种皮颜色相关分析

用AAS方法测定了弥勒县相同生态条件下种植的27份有色稻和34份普通稻糙米4种矿质元素含量,并对有色米和普通米Fe、Zn、Cu和Mn含量进行了比较研究。结果表明,有色稻米4种矿质元素含量明显高于无色稻米,其差异均达显著水平,其含量高低依次为Zn>Fe>Cu>Mn;对黑、褐、红、黄、绿5种不同种皮颜色的稻米4种矿质元素含量进行比较研究,发现稻米Fe含量(mg/kg)依次为黑>绿>褐>红>黄,Zn含量(mg/kg)依次为绿>红>黑>褐>黄,Cu含量(mg/kg)依次为黑>褐>红>黄>绿,Mn含量(mg/kg)依次为褐>黑>红>黄>绿;并且Fe和Mn含量在不同颜色稻米间差异均达显著水平,与有色米种皮颜色密切相关,而Zn和Cu差异不显著,与有色米种皮颜色关系不大。黑米和褐米富Fe、Zn、Cu和Mn,绿米富Fe和Zn,红米富Zn和Cu,黄米4种矿质元素含量较低,Fe、Cu和Mn均低于普通稻米。     

中国稻种资源收集、保存和更新现状

截止2003年,我国共编目稻种资源77541份,其中各种类型所占百分比大小顺序为:地方稻种(68.68%)、国外引进稻种(12.65%)、野生稻种(9.45%)、选育稻种(6.96%)、杂交稻"三系"资源(2.09%)、遗传标记材料(0.16%);在国家长期库中共保存稻种资源69133份,其中各种类型所占百分比大小顺序为:地方稻种(71.38%)、国外引进稻种(12.16%)、野生稻种(8.09%)、选育稻种(6.52%)、杂交稻"三系"资源(1.54%)、遗传标记材料(0.18%)、其他(0.12%).加强选育品种、品系、突变体的收集和保存;重视国外稻种资源的收集与引进;开展地方稻种的纯系筛选与保存;持续开展稻种资源的繁种更新;开展已筛选优异种质资源的确认和提供利用,这是今后稻种资源收集和保存工作的重要研究任务.     

杂草稻的研究现状与展望

杂草稻属于野生稻与栽培稻中间类型.一方面,由于杂草稻与栽培稻之间的前期形态、生理生化特性相似,很难化学控制其在稻田发生,影响水稻产量与品质;另一方面,杂草稻长期自然生长繁衍,其抗病、虫、寒、旱、盐碱等特性优于栽培稻,而且与栽培稻的亲缘关系相对接近,是一种改良栽培稻抗逆性的天然基因库.     

不同类型特种稻种质营养及功能性成分含量的差异

本研究以具有有色种皮、巨胚、甜味、香味、糯性等单一特殊性状或2个以上特殊性状聚合于一体的新创制特种稻种质39份和1份白米种质(对照)为试验材料,进行了黑米、黑褐米、红米、香糯米、黑巨胚糯米、红巨胚糯米、巨胚糯米、黑甜米、红甜米、白甜米等不同类型特种稻种质的营养及功能性成分含量的差异评价。结果表明,供试特种稻类型在大部分氨基酸含量和矿质元素含量上与白米差异不显著,只在个别氨基酸和矿质元素含量上与白米呈显著或极显著差异。黑褐米、红米、黑巨胚糯米、红巨胚糯米、巨胚糯米、红甜米和白甜米等7种类型的赖氨酸含量显著或极显著高于白米,高2.91%~24.68%;黑米、黑褐米、红米、香糯米、黑巨胚糯米和红甜米等6种类型的铁含量显著或极显著高于白米,高17.62%~68.09%;黑褐米、红米、黑巨胚糯米、红巨胚糯米、黑甜米、红甜米、白甜米等7种类型的钙含量显著或极显著高于白米,高23.56%~49.46%;黑米、黑褐米、红米、黑甜米、红甜米、白甜米等6种类型的锌含量显著或极显著高于白米,高12.21%~55.87%。由此表明,具有有色种皮、巨胚、甜味、香味、糯性等单一特殊性状或2~3个特殊性状的聚合对赖氨酸含量与铁、钙和锌含量的提高方面具有一定的增加效应,认为在今后以赖氨酸、铁、钙和锌含量为目标性状的功能性水稻育种中,多个特殊性状的聚合将是增加上述功能性成分含量的有效途径之一。通过鉴定评价,从创新种质中还筛选出一些功能性成分含量相对较高的优异种质,白甜米1553和红巨胚糯米1476的赖氨酸含量较高,比白米分别高29.37%和23.42%;红米1439和红米1440的铁含量较高,比白米分别高99.05%和80.00%;黑甜米1511和黑甜米1515的硒含量较高,比白米分别高194.14%和136.48%;白甜米1551和香糯米1446的γ-氨基丁酸含量较高,比白米分别高14.56%和11.83%;黑巨胚糯米1464和黑米1432的花色苷含量较高,比供试18份有色稻米的平均值分别高253.23%和248.83%。这些新创制的功能性成分含量较高的水稻种质有待于今后在育种、生态适应性鉴定与产业化中进一步得到利用。     

芽胞杆菌在防治水稻稻瘟病中的应用及生防机制

芽胞杆菌具有人畜安全、不污染环境、病原菌不易产生抗药性、抗逆性强和促进植物生长等优点,是稻瘟病防治上的重要生防菌。芽胞杆菌的生防机制主要包括竞争作用、拮抗作用和诱导抗病性。芽胞杆菌定殖在水稻植株上,产生抗菌活性物质抑制稻瘟病菌的生长,诱导水稻产生抗病性,对水稻植株具有促生作用,可以挽回水稻产量损失。芽胞杆菌可以制备生防制剂用来防治我国南方稻区和北方稻区的稻瘟病危害,在水稻产业的可持续发展中对稻瘟病的生物防治具有指导意义。本文主要综述芽胞杆菌在防治水稻稻瘟病中的应用研究、芽胞杆菌在防治水稻稻瘟病中的生防机制、影响稻瘟病生防芽胞杆菌防效的因素。     

长江中下游热量资源时空演变特征及其对双季稻种植的影响

热量资源的时空特征是影响双季稻种植布局的主要气候因素.为了分析近52年长江中下游主要双季稻区热量资源的变化特征及其对双季稻种植的影响,本研究选取湖南、江西和湖北3省作为双季稻代表性研究区域,根据3省240个气象站1961—2012年的地面气象观测资料,利用气候倾向率及突变分析等方法,分析研究区双季稻温度生长期的热量资源和双季稻的安全生长期的演变规律,在此基础上分析研究时段内不同水稻品种搭配布局及种植北界的变迁.结果表明: 近52年双季稻温度生长期及安全生长期的热量资源均呈明显增多趋势,其中,双季稻生长期及安全生长期的热量资源由寡至多的突变点均出现在2000年;双季早稻安全播种期提前3～7 d、双季晚稻安全齐穗期延后2 d,双季稻安全生长期平均延长7 d;双季稻种植北界明显北移了200 km左右,至33° N附近;同时,双季稻品种搭配由“早熟早稻+中熟晚稻”和“中熟早稻+中熟晚稻”向“中熟早稻+晚熟晚稻”转变.长江中下游双季稻区热量资源的增加为双季稻种植北界北移、中晚熟品种替代早中熟品种提供了可能.     

二化螟水稻类群和茭白类群成虫产卵与幼虫寄主选择行为的比较研究

实验室木箱条件下进行的二化螟水稻类群与茭白类群成虫产卵选择性试验结果表明,两类群在水稻与茭白上所产的卵块和卵粒的分布及孵化率无显著差异;但均有将不能孵化卵产在非本寄主上的倾向．通过Y形嗅觉仪进行的幼虫寄主选择行为的试验结果显示,除茭白类群1龄幼虫对水稻与茭白的趋性分别为30．00％与66．67％,有显著差异(P≤0．05)外,1龄幼虫对两寄主组织的趋性无显著差异;对水稻与茭白叶片、叶鞘的趋性反应中,水稻类群4龄、6龄幼虫对叶片,2龄、4龄幼虫对叶鞘差异显著,而茭白类群2—6龄幼虫均差异显著(P≤0．05)．研究结果表明,两类群已开始种下分化,其中茭白类群对本寄主的专化程度大于水稻类群。     

水稻垩白的研究现状与改良策略

文章综合分析了水稻垩白与其他稻米品质性状的相关性、垩白形成机理、经典遗传以及分子遗传方面的国内外研究进展。表明垩白形成是一个复杂的生理过程, 与稻株“源-库”关系、籽粒灌浆动态以及胚乳内淀粉的合成与积累密切相关。垩白属于复杂的数量性状, 其遗传具有母体效应、胚乳效应以及细胞质效应, 还受环境条件的影响。在多条染色体上存在一些稳定表达的控制垩白性状的QTL, 其中3个与垩白形成相关的影响淀粉合成、淀粉代谢和果实发育的基因已被克隆。然而, 关于垩白的形成机制和调控网络目前仍不清楚。在育种实践中, 降低垩白仍是我国优质稻育种, 尤其是籼稻品质育种的主要目标之一。文章对今后稻米垩白的遗传研究方向及其改良措施进行了讨论。     

Origin and Genetic Diversity of Aromatic Rice Varieties, Molecular Breeding and Chemical and Genetic Basis of Rice Aroma

Aroma is an important quality attribute of rice and is a key determinant of its market value. Among the different groups of aromatic rice varieties ‘Basmati’ from the Indian subcontinent and ‘Jasmine’ from Thailand occupy prime position in the international market. In addition, there are a large number of premium short-grain aromatic rice varieties cultivated by farmers in India and South-East Asia that have not been fully commercially utilised as yet. The origin and evolution of aromatic rice varieties is being unravelled by application of genomic tools. The common alleles of aroma gene seem to have their origin in the aromatic group of rice varieties native to the Sub-Himalayan region. Of more than two hundred volatile compounds present in the rice grain, 2-acetyl-l-pyrolline (2-AP) is considered as the key aroma compound present in almost all the aromatic rice varieties. However, there is significant variation in the type and intensity of aroma in the different groups of aromatic rice varieties suggesting involvement of additional chemical compounds in varying proportions. Studies have been undertaken to understand the genetics of rice aroma and to map the genes or quantitative trait loci (QTL) controlling aroma expression. Of the three mapped aroma QTL, qaro8.1 located on rice chromosome S is the most significant and it represents a non-functional allele of BADH2 gene coding for enzyme betaine aldehyde dehydrogenase. Functional allele of the BADH2 gene makes rice non-aromatic. Similarly, specific alleles of BADH1 gene located on rice chromosome 4 within the aroma QTL qaro4.1 show association with the aromatic rice varieties. The gene underlying QTL qaro3.1 on chromosome 3 has not yet been deciphered. Functional molecular markers have been developed for the major aroma QTL on chromosome S and marker-assisted breeding for high yielding aromatic rice varieties is now a reality. To safeguard the reputation of Basmati rice an international code of practice has been developed where DNA markers help check the purity of commercial samples. There is need to use advanced genomic and metabolomic approaches to further study the minor genes controlling rice aroma and understand the variation in type, intensity and stability of rice aroma. It is also required to improve the production and marketing of short grain aromatic rice varieties.     

水稻稻瘟病和纹枯病抗性鉴定方法

水稻(Oryza sativa)是世界上最重要的粮食作物, 但稻瘟病和纹枯病等病害严重危害水稻的产量和品质, 给我国乃至全球粮食安全带来巨大威胁。鉴定水稻抗病资源、克隆抗病基因、揭示抗性机理并在育种中加以利用, 对抵御水稻病害和保障粮食安全具有十分重要的作用。准确评价水稻资源的抗病性, 是开展抗病机理研究和育种生产应用的关键环节。该文详述了水稻幼苗期人工喷雾接种、分蘖期和孕穗期田间注射接种与离体叶片戳伤接种的稻瘟病抗性鉴定方法, 以及水稻分蘖期田间接种、孕穗期温室接种和离体茎秆接种的纹枯病抗性鉴定方法, 以期为同行鉴定水稻资源、开展抗病理论和应用研究提供参考。     

水稻耐冷性鉴定评价方法

水稻耐冷性是我国东北和西南高海拔地区、日本、韩国和朝鲜等国水稻育种的重要研究目标,至今许多学者对水稻耐冷性进行了广泛的研究,并且目前所采用的耐冷性鉴定评价方法已基本成熟,但国内还没有对其进行技术规范化.本文汇总了国内外至今所采用的水稻耐冷性鉴定方法和耐冷指标及分级标准等,将为水稻耐冷性种质资源鉴定和育种以及我国水稻耐冷性鉴定评价技术规范的制定提供参考依据.     

Towards molecular breeding and improvement of rice in China

China is the largest producer and consumer of rice in the world and a pioneer in applying hybrid rice technology. Although hybrid rice has contributed greatly to Chinese agriculture in the past decades, its potential to improve grain quality further is being questioned. However, to meet the challenges posed by severe crop damage by pests and diseases, the extensive use of pesticides and chemical fertilizers, and a shortage of water and energy, more elite rice cultivars are needed. In recent years, China has seen continued improvements in rice genetics, powered by functional genomics as a way forward to safeguard its rice production. Here, we briefly review the current status of rice breeding in China through strategies integrating hybrid rice technology, molecular marker-assisted breeding, functional genomics and genetically modified rice.     

Anoxia tolerance and ethanol sensitivity of rice and oat coleoptiles

Anoxia tolerance and ethanol sensitivity of rice (Oryza sativa L.) and oat (Avena sativa L.) seedlings were evaluated to clarify their growth habit in anoxia. Anoxic stress inhibited elongation and dry weight gain of coleoptiles of the oat and rice seedlings; however, the inhibition of the oat coleoptiles was much greater than that of the rice coleoptiles. Anoxic stress increased endogenous ethanol concentration and alcohol dehydrogenase activity in oat and rice coleoptiles and their increases in the rice coleoptiles were much greater than those in the oat coleoptiles. At concentrations greater than 30 mM and 300 mM, exogenously applied ethanol inhibited the elongation and weight gain for the oat and the rice coleoptiles, respectively, and the inhibition was increased with increasing ethanol concentrations with marked inhibition being achieved on the oat coleoptiles. These results suggest that anoxia tolerance and induction of ethanolic fermentation in anoxia may be greater in rice than oat, and ethanol sensitivity of rice may be lower than that of oat.     

野生稻有利基因的发掘和利用

摘要: 野生稻作为栽培稻的野生亲缘种, 具有许多优良的性状和有利基因, 是栽培稻品种进一步改良的天然遗传种质资源库。其中, 野生稻对病虫害的抗性、对各种逆境的耐受性以及胞质雄性不育等, 已广泛应用于现代栽培稻的育种改良。文章综述了野生稻种质资源的有利性状及相应控制基因的发掘, 探讨了其在今后水稻育种中的应用潜力。     

水稻不同品种对铅吸收、分配的差异及机理

为探究水稻不同品种对Pb吸收积累的差异及机理,以20个不同基因型水稻品种(系)为材料,采用盆栽方法,研究了Pb在水稻植株各器官中的分配及在籽粒中的分布．结果表明,不同品种间,Pb积累量存在显著差异,但品种间的这种差异与品种类型关系不明显;不同器官、不同生育时期,Pb积累量和积累速率不同;各器官Pb浓度按根、茎、叶、穗、籽粒的顺序大幅度下降,分配到籽粒中的Pb比例很低;根与茎,茎与叶片、穗(抽穗期)、籽粒Pb含量呈极显著负相关;根与叶、穗(抽穗期)、籽粒,叶与穗(抽穗期)、籽粒的Pb含量呈正相关,相关性大多达极显著或显著水平;不同品种抽穗期叶片与成熟期籽粒间的Pb含量达显著正相关;Pb在稻米加工各产物中的分布很不均匀,稻谷经脱壳及精加工1次(2min)后,精米Pb含量仅为籽粒总含Pb量的32．88％．     

Patterns of nucleotide diversity in wild and cultivated rice

There are few reports of the patterns of polymorphism in the non-coding regions of plant genomes. In this study, we explored nucleotide diversity and linkage disequilibrium (LD) in 47 non-coding regions on chromosome 4 of wild and cultivated rice. The cultivated rice retained about 70% of the diversity of wild rice, which was verified by coalescent simulations with one population bottleneck for 198 combinations of duration and population sizes. Multi-locus likelihood analysis showed that the severity of the bottleneck ranged from 2.25 to 3.33, with an average value of 2.70; i.e., the diversity found in the cultivated rice could be explained by a founding population of 2,700 individuals if the initial domestication event occurred over a period of 1,000 years. LD decreased more rapidly in wild rice than in cultivated rice within 10 kb, and the LD observed in cultivated rice was increased at 100–140 kb by comparison with wild rice. The patterns of LD indicated the possibility of a haplotype block in cultivated rice but not in wild rice.     

东北地区杂草稻与栽培稻的遗传多样性及籼粳分化

利用88对籼粳特异性分子标记对收集于我国东北三省的35份杂草稻和36份栽培稻遗传基础及籼粳分化进行研究,结果表明上述标记能够高效地鉴别稻属资源的籼粳属性,共检测到156个等位基因,平均有效等位基因(Na)为1.773。遗传多样性分析表明,东北地区杂草稻多样性水平略高于当地栽培稻,其中杂草稻的等位基因数(Na)、杂合度(He)、基因多样性(Hsk)以及多态性信息含量(PIC)分别为1.659、0.006、0.076和0.085,而东北栽培稻分别为1.557、0.004、0.060和0.067。遗传结构和聚类分析结果表明,东北地区杂草稻与栽培稻具有较近的亲缘关系,均存在一定程度的籼粳分化。进一步对籼粳血缘进行相对量化分析发现,杂草稻的籼型基因型频率(F_i=0.050)略高于当地栽培稻(F_i=0.043)。东北三省籼型基因型频率变化趋势为:辽宁杂草稻(0.062)辽宁栽培稻(0.058)吉林栽培稻(0.048)黑龙江杂草稻(0.041)吉林杂草稻(0.024)黑龙江栽培稻(0.020)。     

The Puzzle of Italian Rice Origin and Evolution: Determining Genetic Divergence and Affinity of Rice Germplasm from Italy and Asia

The characterization of genetic divergence and relationships of a set of germplasm is essential for its efficient applications in crop breeding and understanding of the origin/evolution of crop varieties from a given geographical region. As the largest rice producing country in Europe, Italy holds rice germplasm with abundant genetic diversity. Although Italian rice varieties and the traditional ones in particular have played important roles in rice production and breeding, knowledge concerning the origin and evolution of Italian traditional varieties is still limited. To solve the puzzle of Italian rice origin, we characterized genetic divergence and relationships of 348 rice varieties from Italy and Asia based on the polymorphisms of microsatellite fingerprints. We also included common wild rice O. rufipogon as a reference in the characterization. Results indicated relatively rich genetic diversity (H _e = 0.63-0.65) in Italian rice varieties. Further analyses revealed a close genetic relationship of the Italian traditional varieties with those from northern China, which provides strong genetic evidence for tracing the possible origin of early established rice varieties in Italy. These findings have significant implications for the rice breeding programs, in which appropriate germplasm can be selected from a given region and utilized for transferring unique genetic traits based on its genetic diversity and evolutionary relationships.