新型四倍体水稻创制及其杂种优势利用研究进展

新型四倍体水稻是本研究团队创制的一类高育性多倍体水稻新种质,携带有多种优异基因。该类材料与同源四倍体水稻杂交获得的杂种F₁产量优势明显,具有应用前景。本文首先概述了同源四倍体水稻的研究进展,并重点阐述了新型四倍体水稻创制过程、主要特点、杂种优势表现及其涉及的分子遗传机理,最后提出未来研究的思路及需要解决的问题,为加快新型四倍体水稻在多倍体水稻育种中的利用提供依据。     

籼稻品种浙辐802抗瘟性遗传研究

通过与８个日本鉴别品种杂交和利用日本代表菌系研５４－０４及我国南方稻区菌系９５-ｈ接种鉴定,研究了籼稻品种浙辐８０２的抗性遗传。研究结果表明,该品种对菌系研５４-０４的抗性由 ２对显性基因控制,对菌系 ９５-ｔ２的抗性由 １对显性基因控制。基因等位性分析确认,浙辐８０２中抵抗９５－ｔ２的抗病基因与Ｐｉ－ｉ基因等位,与Ｐｉ－ａ、Ｐｉ－ｓｈ、Ｐｉ－ｋ、Ｐｉ－ｚ、Ｐｉ－ｂ、Ｐｉ－ｔ、Ｐｉ－ｔａ等已知基因位点为非等位关系;抵抗菌系研５４－０４,感染菌系９５-ｔ２的基因与Ｐｉ－ｉ、Ｐｉ－ｋ、Ｐｉ－ｂ、 Ｐｉ－ｔ ４个已知基因位点为非等位关系。对这个基因与其他已知基因的等位性进行了分析,认为它可能是１个未被命名的新基因。     

不同水稻品系幼苗对砷（As）的耐性、吸收及转运

利用琼脂培养基模拟水稻生长的厌氧环境,研究了As对不同水稻品系幼苗生长的影响以及As在其体内的积累及转运特性.结果表明,不同浓度(0～4.0mg/L)的As对供试水稻品系根部干物质积累无显著影响(P>0.05).杂交稻与糯稻的地上部干物质积累随基质中As浓度的增加呈减小趋势,但低剂量的As(0.5mg/L)促进常规稻的生长.水稻地上部的As积累量随基质中As浓度的升高总体均呈增加趋势.水稻根系对As具有较强的吸收与累积能力.水稻根部As的积累量为156.31～504 03mg/kg,占总As含量的63.40～81.90%,远远高于其地上部As的积累量.相比于其它两个品系,糯稻的生物量积累高,耐性指数较大,根部及地上部对As的积累量较低,因此更适合种植在As污染土壤.     

Arsenic tolerance, uptake and translocation by seedlings of three rice cultivars

By simulating the anaerobic conditions with agar nutrient solutions, effect of arsenic (As) on the growth and As uptake by hybrid, conventional and glutinous rice cultivars were studied. It showed insignificant effect of As on the root dry weights of three rice cultivars when treated by As of different concentrations. The shoot dry weights of hybrid and glutinous decreased with As concentrations increasing, while low concentrations of As (0.5 mg L^?1) could enhance the growth of conventional rice. Generally, As concentrations in roots and shoots increased as As concentrations of treatment solutions increasing. The root system had strong ability to uptake and accumulate As. The root As concentrations ranged from 156 to 504 mg kg^?1, representing 63.40%–81.90% of the total As concentrations in rice, which were much higher than shoot As concentrations. The fact that the glutinous rice had higher biomass, higher tolerance, and lower As concentrations in its roots and shoots than the other two rice cultivars proved that the glutinous rice was more applicable to As-polluted soils.     

不同浓度Al3+胁迫对水稻根生长的影响

铝毒害是酸性土壤限制农作物产量的主要因素之一。本文以水稻为材料,探讨了不同浓度的AlCl3(0、50、100、150 mmol.L-1)胁迫处理对水稻幼苗根生长的影响。结果表明,随着Al3+浓度和胁迫时间的增加,水稻幼苗根的生长受到抑制,长度和鲜重都减小,根尖细胞死亡的程度增大,根中H2O2含量上升;与对照(未经DMTU预处理)相比,经dimethylthiourea(内源过氧化氢抑制剂)预处理的水稻幼苗在Al3+胁迫下根细胞死亡程度减小,H2O2含量降低,根的生长抑制得到缓解,表明内源H2O2的积累是造成Al3+对水稻幼苗根生长抑制的原因之一。     

Origin,dispersal, cultivation and variation of rice

There are two cultivated and twenty-one wild species of genus Oryza. O. sativa, the Asian cultivated rice is grown all over the world. The African cultivated rice, O. glaberrima is grown on a small scale in West Africa. The genus Oryza probably originated about 130 million years ago in Gondwanaland and different species got distributed into different continents with the breakup of Gondwanaland. The cultivated species originated from a common ancestor with AA genome. Perennial and annual ancestors of O. sativa are O. rufipogon and O. nivara and those of O. glaberrima are O. longistaminata/, O. breviligulata and O. glaberrima probably domesticated in Niger river delta. Varieties of O. sativa are classified into six groups on the basis of genetic affinity. Widely known indica rices correspond to group I and japonicas to group VI. The so called javanica rices also belong to group VI and are designated as tropical japonicas in contrast to temperate japonicas grown in temperate climate. Indica and japonica rices had a polyphyletic origin. Indicas were probably domesticated in the foothills of Himalayas in Eastern India and japonicas somewhere in South China. The indica rices dispersed throughout the tropics and subtropics from India. The japonica rices moved northward from South China and became the temperate ecotype. They also moved southward to Southeast Asia and from there to West Africa and Brazil and became tropical ecotype. Rice is now grown between 55°N and 36°S latitudes. It is grown under diverse growing conditions such as irrigated, rainfed lowland, rainfed upland and floodprone ecosystems. Human selection and adaptation to diverse environments has resulted in numerous cultivars. It is estimated that about 120000 varieties of rice exist in the world. After the establishment of International Rice Research Institute in 1960, rice varietal improvement was intensified and high yielding varieties were developed. These varieties are now planted to 70% of world's riceland. Rice production doubled between 1966 and 1990 due to large scale adoption of these improved varieties. Rice production must increase by 60% by 2025 to feed the additional rice consumers. New tools of molecular and cellular biology such as anther culture, molecular marker aided selection and genetic engineering will play increasing role in rice improvement.     

Reaction of incompatible isolate of Pyricularia grisea on rice leaves stripped of epicuticular wax reflects blast conduciveness of soils

Upland rice cultivars were evaluated in the greenhouse for susceptibility to the rice blast disease caused by Pyricularia grisea Sacc., on two upland soils from the Philippines previously considered to be “blast conducive” and “blast non-conducive”. Under monocyclic inoculation tests plants grown in conducive soil showed significantly greater lesion development than plants of the same cultivar grown in non-conducive soil: cultivars considered to be susceptible to the isolates used showed increased number of susceptible-type lesions; resistant cultivars showed increased number of hypersensitive resistant-type lesions. A similar effect was observed under polycyclic tests where several generations of the pathogen were allowed to develop on the test plants. Dilution of conducive soil with non-conducive soil resulted in a corresponding reduction of disease severity, although this was most pronounced on resistant cultivars. Removal of leaf epicuticular waxes (LEW) using organic solvents increased the number of resistant-type lesions on resistant cultivars grown in both soils following inoculation. Susceptible plants were not suitable for quantifying the relative blast conduciveness of a soil because of the extreme environmental sensitivity of the bioassay and the tendency of lesions to coalesce. Comparing numbers of resistant-type lesions on leaves of plants stripped of LEW and inoculated with an incompatible P. grisea isolate among plants grown in different soils proved to be a satisfactory means of distinguishing the relative blast conduciveness of soils under controlled conditions. This method was field tested in eastern India and results corroborated farmer assessment of which soils were blast conducive. Using incompatible isolate-cultivar combinations and LEW-free leaves is proposed as a simple bioassay for assessing blast conduciveness of soils and should prove useful in regional characterization of rice blast risk.     

从中国水稻育种经验看遗传资源的意义

新中国成立以来水稻单位面积产量提高为三倍以上,本文对于１９４９～１９６０、１９６１～１９７５、１９７６～１９９０三个阶段水稻育种工作中新的遗传资源所起的关键作用作了分析,强调指出在种质资源的收集、整理、研究利用方面开展国际合作的必要性。     

Nutritional enhancement of rice for human health: The contribution of biotechnology

Micronutrient malnutrition is widespread, especially in poor populations across the globe where daily caloric intake is confined mainly to staple cereals. Rice, which is a staple food for over half of the world's population, is low in bioavailable micronutrients required for the daily diet. Improvements of the plant-based diets are therefore critical and of high economic value in order to achieve a healthy nutrition of a large segment of the human population. Rice grain biofortification has emerged as a strategic priority for alleviation of micronutrient malnutrition. Nutritional enhancement of crops through conventional breeding is often limited by the low genetic variability for required dietary micronutrient levels. In this case, biotechnology strategies offer effective and efficient perspectives. In this review, we discuss genetic engineering approaches that have been successful in the nutritional enhancement of rice endosperm. These advancements will make substantial contributions to crop improvement and human nutrition. Their practical application, however, also demands visionary changes in regulatory policies and a broader consumer acceptance.     

Cadmium,copper, and zinc levels in the rice and rice field soil of Houston,Texas

Fifty-one pairs of hulled rice samples and the soil from which each rice sample was grown were analyzed for heavy metals in August, 1979, in order to estimate the background contamination of cadmium (Cd), copper (Cu), and zinc (Zn) in rice grown in the Houston, Texas area. Both samples were divided into three groups by soil types and colors. The cadmium concentration in Texas rice was only one-half to one-quarter lower than that of Asian rice. However, the levels of Cu and Zn in rice in Texas were similar to those reported. Soil heavy metals were lower than ever reported, but these values were consistent with the geochemical characteristics of the Texas Houston area. No particular relationship was found between the three metals in rice and the metals in soil where the sampled rice was grown.     

陕西三种特种稻米氨基酸及品质分析

以陕西洋县产茉莉香米、红香米和绿香粳米等 3种特种稻米为材料 ,分析了氨基酸及其它品质指标。结果表明 ,茉莉香米、红香米和绿香粳米均含有 1 7种氨基酸 ,氨基酸总含量 (mg/ 1 0 0 g)分别为 730 0、72 70、74 90 ;除Trp外 ,7种必需氨基酸占氨基酸总量分别为 34 .6 %、34 .5 %、34 .8% ;Lys含量 (mg/ 1 0 0g)分别为 5 5 0、5 2 0、5 30 ;粗蛋白质含量分别是 9.94 %、9.2 3%、8.5 2 % ;Cu含量 (mg/ 1 0 0g)分别是 0 .6 2、0 .94、0 .79;Zn含量 (mg/ 1 0 0 g)分别是 1 .99、1 .75、2 .0 2 ;Fe含量 (mg/ 1 0 0 g)分别是 1 .5 5、3.70、4 .5 0 ;直链淀粉含量分别是 1 5 .6 %、3.7%、1 5 .1 % ;胶稠度分别是 33mm、4 0 .6mm、78mm ;糊化温度分别是 6 .1级、6 .8级、7级 ;水分含量分别是 1 1 .2 7%、1 1 .5 5 %、1 2 .5 2 %。这 3种特种稻品质较优 ,具有推广价值     

籼、粳杂种的“随体丢失”

1985—1986,观察籼、粳及籼,粳F_1杂种终变期核仁染色体数,籼为2个二价核仁染色体,粳为1个二价核仁染色体,籼、粳F_1杂种核仁染色体数与父本水稻的核仁染色体数相同。由此,讨论了“随体丢失”在水稻育种,粳稻起源及遗传学方面的意义。     

试论野生稻高蛋白种质在水稻育种中的应用

本文探讨野生稻高蛋白种质在水稻育种中应用的必要性、意义和可行性,提出研究应用的发展重点;认为水稻品质育种应利用野生稻高蛋白种质,加强专用水稻育种和高蛋白种质分子学研究。     

有机大米产业化与野生稻种质利用

针对有机大米产量明显低于普通大米的问题,本文论述了有机大米产业化与野生稻优异种质利用的关系,分析了野生稻优异基因利用现状、目前存在的问题以及解决问题的途径。提出在有机水稻品种选育过程中,通过利用野生稻优异基因,提高有机水稻品种抗病虫性、抗逆性(耐寒、耐旱、耐贫瘠)和光合效率等特性,从而推动野生稻优异种质利用,提高企业经济效益,解决化学物质残留和污染等问题。     

A spectrum of genes expressed during early stages of rice panicle and flower development

To unravel gene expression patterns during rice inflorescence development, particularly at early stages of panicle and floral organ specification, we have characterized random cloned cDNAs from developmental-stage-specific libraries. cDNA libraries were constructed from rice panicles at the stage of branching and flower primordia specification or from panicles undergoing floral organogenesis. Partial sequence analysis and expression patterns of some of these random cDNA clones from these two rice panicle libraries are presented. Sequence comparisons with known DNA sequences in databases reveal that approximately sixtyeight per cent of these expressed rice genes show varying degrees of similarity to genes in other species with assigned functions. In contrast, thirtytwo per cent represent uncharacterized genes. cDNAs reported here code for potential rice homologues of housekeeping molecules, regulators of gene expression, and signal transduction molecules. They comprise both single-copy and multicopy genes, and genes expressed differentially, both spatially and temporally, during rice plant development. New rice cDNAs requiring specific mention are those with similarity toCOP1, a regulator of photomorphogenesis inArabidopsis; sequence-specific DNA binding plant proteins like AP2-domain-containing factors; genes that specify positional information in shoot meristems like leucine-rich-repeat-containing receptor kinases; regulators of chromatin structure like Polycomb domain protein; and also proteins induced by abiotic stresses.     

转多基因水稻植株的获得

将2-3个外源目的基因与筛选标记基因hpt连在同一个载体上,用基因枪法对1个梗稻品种和4个和稻品种进行了转化。梗稻中花8号转化频率最高为56.4%,和稻七丝软占、特青、奇妙香、九六零转化频率分别为6.4%,2.5%,2.8%和1.7%。分子杂交实验证明,通过两次潮霉素抗性筛选的To代再生植株100%含有hps基因,其中70%以上含有外源目的基因的完整表达结构。遗传分析表明,大部分TI代植株中 潮霉素抗敏比符合孟德尔31的分离规律。     

亚洲栽培稻起源、演化中两个重要稻种类型的研究

分布子云南及南亚的光稃稻和镰刀谷在研究亚洲栽培稻(O.sativa L.)的起源、演化及稻作育种上有重要意义。它们在分类上的地位往往被误分,进而影响这些类型的开发利用。研究表明,光稃稻是普通野生稻被引上亚洲的热带与亚热带山区在旱地上首先被人类驯化成的原始粳型陆稻,当其进一步被引向高海拔和高纬度时则演化成普通粳稻。镰刀谷迄今多被划为籼稻,我们的初步研究表明,镶刀谷大部分属粳稻,其中也包括一部分籼稻。它的起源及其分类上的地位尚待研究。     

紫黑米种质功能成分综合研究与利用

紫黑米富含花青素、黄酮、多酚等功能成分,着重介绍了花青素等功能成分的含量差异及其影响因素、功能研究、基于代谢机理与育种及食品加工工艺的功能成分强化研究、功能成分的利用及提取工艺等领域的研究进展。针对国内外紫黑米功能成分综合研究利用进展,提出紫黑米的育种利用、食品保健、医药研发和分子机理研究及其新型功能食品研制与产业化对策,以期为紫黑米相关研究提供参考。     

双低两用温敏核不育水稻低温条件下花粉发育的细胞学观察

双低两用温敏核不育水稻96－5－2S在11.31－20.19℃低温条件下,花粉母细胞形成、减数分裂和花粉后期发育均正常,最后形成充满淀粉的成熟花粉,而作对照的两用温敏不育水稻陆18S在相同低温条件下,除花粉母细胞形成早期发育正常外,花粉母细胞晚期、减数分裂期均有异常,败育主要发生在单核小孢子靠边期,没有形成成熟花粉,结果表明,96－5－2S桫胜殖期抗寒性强,低温生理障碍雄性不育临界温度低。     

水稻条叶枯病毒基因组组分3的克隆与序列分析

利用ＲＴ－ＰＣＲ技术,合成并扩增了水稻条叶枯病毒（ＲＳｔＶ）中国云南分离 物基因组组分３的全长ｃＤＮＡ。将ＰＣＲ产物克隆在载体ｐＣＲⅡ上,进行全序列测定。将所得核苷酸序列及其所推导的氨基酸序列与日本分离物Ｔ进行同源性比较,结果表明,在核苷酸水平上,两分离物的５’端非编码区序列相同,ｖＯＲＦ、ｖｃＯＲＦ及基因间非编码区序列的同源性分别为９７．６％、９６．８％及８７．６％,而３’端非编码区同源性为９８