Bph15在非洲栽培稻、药用野生稻和宽叶野生稻中的BAC-FISH比较物理定位

用覆盖抗褐飞虱基因Bph15的两个BAC克隆,即20M14 (27 kb)和64O9 (36 kb)作为探针,对非洲栽培稻、药用野生稻和宽叶野生稻体细胞染色体进行荧光原位杂交(FISH)。两个BAC克隆均被定位于非洲栽培稻和药用野生稻第4染色体的短臂上,杂交信号的百分距离分别为37.03±4.11和81.22±3.62,相应的信号检出率为41.18%和38.22%。在宽叶野生稻中,有两对同源染色体同时检出信号,分别定位于染色体的短臂和着丝粒区,信号距着丝粒平均百分距离分别为87.78±5.23和0,信号检出率为52.58%。由此推知,这两个BAC克隆在非洲栽培稻和药用野生稻的第4染色体分布同线且同区,并且在宽叶野生稻的DD基因组也存在Bph15基因的同源序列。在未封阻的情况下,BAC克隆在非洲栽培稻的多条染色体上有杂交信号,表明它和栽培稻C_0t-1 DNA在一定程度上具有同源性。上述结果初步显示Bph15在3个稻种染色体中的相对位置。文章讨论了Bph15在3个种间的关系,为有效分离和利用Bph15基因提供了有益的依据,对不同基因组及二倍体和四倍体中功能基因可能进化机制的分析提供了线索。     

云南传统栽培稻品种waxy基因序列分析

栽培稻是全球最重要的粮食作物之一,waxy基因对栽培稻的品质改良研究具有重要意义.云南是亚洲栽培稻多样性分布中心之一,传统品种丰富.本研究依据云南不同稻区、不同海拔选取99份传统栽培稻品种,对waxy基因序列进行分析.结果显示,供试品种中waxy基因序列包含36个单倍型,其中52个品种存在23 bp碱基的插入,而47个...     

Bph15在非洲栽培稻、药用野生稻和宽叶野生稻中的BAC-FISH比较物理定位

用覆盖抗褐飞虱基因Bph15的两个BAC克隆，即20M14 (27 kb)和64O9 (36 kb)作为探针，对非洲栽培稻、药用野生稻和宽叶野生稻体细胞染色体进行荧光原位杂交(FISH)。两个BAC克隆均被定位于非洲栽培稻和药用野生稻第4染色体的短臂上，杂交信号的百分距离分别为37.03±4.11和81.22±3.62，相应的信号检出率为41.18%和38.22%。在宽叶野生稻中，有两对同源染色体同时检出信号，分别定位于染色体的短臂和着丝粒区，信号距着丝粒平均百分距离分别为87.78±5.23和0，信号检出率为52.58%。由此推知，这两个BAC克隆在非洲栽培稻和药用野生稻的第4染色体分布同线且同区，并且在宽叶野生稻的DD基因组也存在Bph15基因的同源序列。在未封阻的情况下，BAC克隆在非洲栽培稻的多条染色体上有杂交信号，表明它和栽培稻C_0t-1 DNA在一定程度上具有同源性。上述结果初步显示Bph15在3个稻种染色体中的相对位置。文章讨论了Bph15在3个种间的关系，为有效分离和利用Bph15基因提供了有益的依据，对不同基因组及二倍体和四倍体中功能基因可能进化机制的分析提供了线索。     

不同水稻种质中渗透胁迫抗性基因DREB2A的遗传多样性分析

本研究旨在分析转录因子DREB2A基因在不同水稻种质中的遗传多样性,以期为水稻耐渗透胁迫遗传改良提供分子工具。利用单倍型分析、系统进化树、遗传距离和密码子偏好性分析,对85份不同类型水稻种质中DREB2A基因的功能性核苷酸序列变异及遗传多样性进行了研究。共鉴定出55个核苷酸变异位点,其中12个位于编码区,43个位于非编码区;鉴定出12个DREB2A等位基因型,其中来自非洲栽培稻(Oryza glaberrima)的3个等位基因型表现大片段变异;根据DREB2A基因的序列变异鉴定出39个单倍型,其中33个为新单倍型;将所有单倍型分为三组（Group I、II和III）,其中非洲栽培稻(Oryza glaberrima)中的10个单倍型单独分为一组(Group III);系统进化树、遗传距离和密码子偏好性分析均表明Group III与其他两组具有较大差异。对85份不同类型水稻种质中DREB2A基因的序列分析表明,非洲栽培稻(Oryza glaberrima)中的DREB2A等位基因在序列变异、系统进化关系和密码子偏好性方面均明显不同于其他种质材料中的等位基因。     

这些农作物的“祖籍”在哪里?

小麦:原产亚洲西部,我国是世界栽培小麦最早的国家之一。水稻:水稻栽培稻分亚洲栽培稻和非洲栽培稻,亚洲栽培稻原产于包括我国南方的亚洲东南地区。     

中国古栽培稻的研究

用粒形指标、双峰乳突判别函数和后验概率分析法,对长江流域10个水稻遗址、时间跨度2000-1500。年前的68粒古栽培稻谷作了研究。发现古栽培稻具有性状变异的广域性,性状变域二维分布的独立性,性状组合的多型性,演化特征的原始性和过渡性。故将古栽培稻认定为1个与现代的籼稻、粳稻和普通野稻有别的类型,即古栽培稻类型。     

非洲栽培稻基因渗入系的稻米品质鉴定与筛选

稻米品质改良越来越成为现代水稻育种工作的重要目标,探明新选育非洲栽培稻基因渗入系的稻米品质潜力将为其在水稻优质育种工作中的进一步应用奠定基础。对50份非洲栽培稻基因渗入系的12个稻米品质性状进行了考察鉴定,并结合相关性分析、聚类分析和判别分析方法对其综合品质表现进行了分类评价。供试材料均表现较高的糙米率(≥74.19%)、精米率(≥67.83%)、较大的长宽比(≥2.79)和低水分含量(≤13.03%),多数选系具有适宜的直链淀粉含量(17.00-22.00%)。聚类分析将供试材料分为5组,其中第I组的综合米质性状最优;典型判别分析获得2个典型判别函数,分别可解释89.5%和7.2%的方差变异,主要反映垩白粒率和长宽比等指标。新选育的非洲栽培稻基因渗入系在糙米率、精米率、长宽比和直链淀粉含量方面具有优势,垩白粒率和长宽比是非洲栽培稻基因渗入系品质改良的重要指标；本研究将为非洲栽培稻基因渗入系在高产优质水稻新品种选育中的研究应用提供依据。     

亚洲杂草稻红色果皮分子鉴定及其Rc-bHLH序列多态性分析

多数杂草稻的果皮是红色,该特征可用于稻田中杂草稻的早期的初步鉴定,也可用于水稻果皮Rc/rc基因的起源进化研究。本研究利用红色果皮Rc基因第六外显子的In Del标记RID14对来自亚洲不同稻作区的199份杂草稻(O.sativa f.spontanea)、24份栽培稻(O.sativa)和9份野生稻(O.rufipogon)进行基因型鉴定并与表型比对;同时对9份代表性杂草稻Rc-b HLH位点的DNA序列进行测序,并将其与下载的29份栽培稻(籼,粳)和14份野生稻的对应序列进行比对分析。研究结果表明:(1)亚洲杂草稻的果皮颜色的表型多样,多数(84.4%)为红色或褐色(由浅至深)、少数(15.6%)为白色,其基因型与表型鉴定结果高度一致;杂草稻红色果皮Rc基因第六外显子均为无14 bp缺失的类型,仅有一份中国东北杂草稻除外(为14 bp缺失型),揭示用RID14标记可以早期快速的鉴定稻田中红色果皮杂草稻;(2)测试的9份杂草稻其Rc-b HLH位点的DNA序列均较为保守,其中出现4个突变位点;(3)在Rc-b HLH部分区域(1~115 bp),红色果皮的籼型栽培稻、杂草稻和野生稻的DNA序列相同,但红色果皮粳型栽培稻与白色果皮籼型栽培稻和杂草稻在106 bp处存在一个A/G替换;(4)通过对比野生稻和栽培稻,杂草稻在Rc-b HLH位点核苷酸多态性多态性最高,但是野生稻在该位点Tajima'D检验值呈显著,说明Rc-b HLH位点在野生稻中有选择性;通过聚类分析发现分为2个类群,类群1由白色果皮的杂草稻、籼型栽培稻和红/白果皮的粳型栽培稻组成;类群2由红色果皮的栽培稻(籼型)、杂草稻和野生稻组成。该结果暗示:在粳稻区,白色果皮的亚洲杂草稻可能由栽培稻退化返祖而形成的;在籼稻区,红色果皮的亚洲杂草稻可能经由栽培稻及野生稻杂交(如籼籼交或栽野交)演化而来。     

江苏省杂草稻遗传多样性及其起源分析

前期调查研究表明江苏是中国杂草稻危害最严重的省份之一,尤其以苏中地区最甚。因此,本文利用具有多态性的33个共显性SSR标记,分析苏中地区的11个杂草稻种群以及苏南苏北部分杂草稻样品,以揭示江苏省主要杂草稻的遗传多样性及其来源。结果表明苏中地区11个杂草稻群体总的遗传多样性(He)为0.1661,Shannon指数(I)为0.2872;多态位点百分率达到87.88%,等位基因数(Na)为2.1515,有效等位基因数(Ne)为1.2887。其中,泰州的遗传多样性最高而南通地区的最低。杂草稻在地区之间的遗传分化(1%)显著小于杂草稻种群之间的遗传分化(39%),更小于种群内的遗传分化(60%)。聚类分析和主成分分析结果表明苏中和苏南地区杂草稻以籼型为主,苏北地区存在少量粳型杂草稻;苏中地区的杂草稻与现有栽培稻品种和普通野生稻没有明显的亲缘关系,但与曾经栽培过的杂交水稻品种有关。因此,本研究相对支持江苏省杂草稻可能主要来自栽培稻的基因重组或回复突变等产生野生性状即返祖遗传的假说。苏北地区的杂草稻可能来源于穞稻与现今栽培稻杂交的后代。     

澧县八十遗址古栽培稻的粒形多样性研究

用类平均数值分类法, 将八十遗址古稻分为七类十一群. 各类间的性状平均值存在不同程度差异, 表明古栽培稻具有类型的多样性, 是一种非野非籼非粳的原始栽培稻复合体(Complex).     

太湖流域粳稻两类群体种子活力性状有利等位变异的发掘

发掘粳稻种子活力性状的优异等位变异和携带优异等位变异的载体材料可为培育适于直播的高活力粳稻品种提供遗传信息和育种材料。以太湖流域粳稻94个品种构成的自然群体和粳稻品种秀水79与粳稻恢复系C堡衍生的247个重组自交家系(RIL)群体为试验材料,利用斜板发芽法发芽,调查生长7d的幼苗根长、苗高和干重3个种子活力性状,采用Tassel软件中的GLM方法和Win QTL Cartographer2.5软件中的CIM方法进行种子活力性状的QTL分析,发掘有利等位变异和相应载体品种。结果表明:(1)在太湖流域粳稻自然群体中共检测到11个与种子活力性状相关联的SSR标记位点,共发掘出42个控制种子活力性状的优异等位变异,其中控制根长的17个,控制苗高的13个,控制幼苗干重的12个。携带种子活力性状优异等位变异且效应值较大的载体材料有滇屯502选早、扬稻6号、开青、籼恢429和C堡等。(2)在RIL群体中共检测到9个与种子活力性状相关的QTL,其中2个控制根长,4个控制苗高,3个控制幼苗干重。除控制幼苗干重的qDW-2a的有利等位变异RM525-143bp来自秀水79以外,其余8个位点的有利等位变异均来自C堡。(3)两类群体均在第1染色体上检测到与根长关联的SSR标记位点,均在第2、第8和第11染色体上检测到与苗高关联的位点,均在第2染色体上检测到与幼苗干重关联的位点,且在自然群体中检测到优于和多于家系群体的等位变异。     

An optimized index for cold tolerance assessment in rice during germination and early seedling stage

Journal of Crop Science and Biotechnology - Cold tolerance at germination and seedling stage is one of the most seeked traits in Southern Brazilian rice (Oryza sativa L.) cultivars, thus, the...     

低磷胁迫对不同水稻品种根系形态和养分吸收的影响

以耐低磷品种大粒稻、莲塘早3号和低磷敏感品种沪占七、新三百粒为材料，采用砂培，测定常磷（10 mg/L）和低磷（0.5 mg/L）两个磷水平下，根系形态、同化物分配、矿质元素吸收、离子吸收耗能的品种差异。实验结果表明，低磷胁迫下，耐低磷品种的总根数、总根长、总根表面积、侧根长、侧根数及侧根密度均明显增加，而低磷敏感     

Seeding date effects on rough rice yield and head rice and selection for stability

The rice (Oryza sativa L.) crop in Arkansas is seeded from late March through early June each year. Farmers need new rice cultivars that not only produce both high rough rice yields and high head rice across this range of seeding dates but do so consistently. Thus, a seeding date study was conducted during 1994 and 1995 at Stuttgart, Arkansas, to study seeding date effects on rough rice yield and head rice and selection for stability. Fourteen rice cultivars were seeded at five dates ranging from late March through mid-June. Kang's yield-stability statistic was used to select cultivars for both high rough rice yields and high head rice as well as stability for both traits. Plant stands from March seedings of each year were significantly lower than for the later seeding dates. Maturity (days to 50 percent heading) was extended at the early seeding dates. Some rice cultivars, such as ‘LaGrue’, had lower and more variable head rice when seeded early. In the June seeding dates each year, ‘Kaybonnet’ produced rough rice yields that were more consistent with yields when planted at the earlier planting dates. ‘Bengal’, ‘Cypress’, ‘Kaybonnet’, and ‘Newbonnet’ were cultivars selected by Kang's stability statistic, which was targeted to select cultivars with stable, high rough rice yields and stable, high head rice. The validity of using Kang's yield-stability statistic for cultivar selection is also evident empirically by the adaptation and wide use of these four cultivars by southern U.S. rice producers. These results indicate that seeding date studies and stability analyses would be useful tools for rice breeders to identify cultivars that will be readily adapted and grown by rice producers. This revised version was published online in July 2006 with corrections to the Cover Date.     

不同穗型常规籼稻品种氮素吸收利用的基本特点

在群体水培条件下,以国内、外不同年代育成的常规籼稻代表品种(2001年为88个、2002年为122个)为材料,测定干物质重(包括根系)、产量及其构成因素、氮素含量等,采用组内最小平方和的动态聚类方法将供试品种按单穗重从低到高依次分为A、B、C、D、E、F 6类,研究各类品种氮素吸收利用的基本特点。结果表明,(1)供试品种单穗重差异较大,适当增加穗重有利于水稻品种产量的提高;(2)不同穗型水稻品种植株含氮率差异较小,大穗型水稻品种抽穗期、结实期、成熟期群体氮素累积量和个体(单穗)氮素累积量均显著大于小穗型品种,个体(单穗)吸氮量特别是抽穗前单穗吸氮量大,是大穗型品种主要生育阶段群体氮素累积量显著大于小穗型品种的重要因素;(3)中等偏大穗型的水稻品种氮素收获指数、氮素籽粒生产效率较高;(4)大穗型水稻品种播种到抽穗天数、全生育期天数较长;(5)氮素累积量、氮素籽粒生产效率均是影响穗重的重要因素,但氮素累积量作用较大;(6)吸氮强度尤其是个体(单穗)吸氮强度是不同穗型水稻品种群体与个体(单穗)氮素累积量差异的主要因素。     

Variations of the vascular bundle system in Asian rice cultivars

Summary The capacity of vascular bundle system transporting assimilates from source to sink is one of the limiting factors for rice (Oryza sativa L.) yield. Genetic variation in vascular bundle system should be investigated for improvement of transporting efficiency. A total of 531 Asian rice cultivars were studied for vascular bundles in the peduncle and its relation to spike morphology. A few difference was detected for the number of primary rachis branches of the spike among the cultivars from various countries. However, the number of vascular bundles significantly differed among the cultivars; those from Nepal, Bangladesh and India bore more vascular bundles than those from Japan. Therefore, the ratio of vascular bundles to rachis branches (V/R ratio) was nearly 1.0 in cultivars from Japan, while those from Nepal, Bangladesh and India ranged from 1.3 to 2.2. Chinese and Indonesian cultivars incuded two types of high and low V/R ratios. Cultivars with high V/R ratio showed positive reactions to the phenol solution, while those with low V/R ratio were negative reactions, suggesting that the former cultivars are of Indica type and the latter of Japonica type. It was concluded that the relationship between vascular bundles and rachis branches differentiated among the ecotypes of Asian cultivated rice.     

Increased regeneration from NaCl-tolerant callus in rice

Summary NaCl-tolerant calli were selected from two Japonica and two Indica rice (Oryza sativa L.) cultivars on basal media containing 6,000, 9,000, 12,000 or 15,000 ppm NaCl. Frequency of callus formation decreased with the increase of NaCl in the medium, especially in Indica. About half of the calli of Japonica cultivars selected on NaCl-ammended media survived 20,000 ppm NaCl but none of the Indica callus survived. In Japonica, more plants were regenerated from calli selected on all concentrations of NaCl media than from NaCl-free medium. Concentration of Cl^- in callus increased dramatically with increased NaCl content but peroxidase activity decreased.     

Brown Planthopper Resistance Genes in Rice： from Germplasm to Breeding

The brown planthopper （BPH）, Nilaparvata lugens Stal （Homoptera： Delphacidae）, is one of the most destructive and widespread insect pests of rice （Oryza sativa） that can be found throughout the rice-growing areas in Asia, causing significant yield loss in susceptible cultivars every year. In addition to causing physiological damage to the rice plant, BPH also causes indirect damage by acting as a vector for rice ttmgro virus, grassy stunt virus and ragged stunt virus. Planting the resistant variety can efficiently restrain the breaking-out of BPH and its damage to rice. Mapping and cloning the BPH resistance genes will be propitious to the development of resistant rice variety and understanding of BPH-resistance mechanism in rice.     

NMR Techniques Coupled with Multivariate Statistical Analysis: Tools to Analyse Oryza sativa Metabolic Content under Stress Conditions

Rice ( Oryza sativa L.) is one of the most important crops in the world and its growth is influenced by several environmental stresses, such as drought and high salinity. In our study, we first investigated the metabolic profile in shoots and roots of two rice cultivars (Arborio and Nipponbare) through ¹H-high-resolution magic angle spinning (HR MAS) and liquid-state nuclear magnetic resonance (NMR) experiments. Drought and salt stress experiments on shoot and root growth showed Arborio seedlings to be more sensitive than those of Nipponbare to these abiotic stresses. Moreover, the metabolic content of the same samples was analysed by liquid-state NMR coupled with multivariate statistical analysis. Principal component analysis highlighted a significant accumulation of amino acids and sugars in shoots and roots under stress conditions and the existence of clear differences between the two analysed rice cultivars. In particular, Arborio seedlings accumulated a higher concentration of amino acids and sugars than Nipponbare seedlings. Furthermore, we also obtained preliminary data about metabolic changes in rice following infection with the fungus Magnaporthe grisea . This study proves that NMR technique coupled with multivariate statistical analysis is a powerful tool to assess a possible correlation between differences in metabolic profile and in tolerance/sensitivity phenotype in rice cultivars.     

Identification of Physiological Traits Underlying Cultivar Differences in Drought Tolerance in Rice and Wheat

Rice is used as a model cereal to study drought response at the molecular level, with the goal of applying results to other cereals. To assess the relevance of results from rice to other species, the kinetics of drought development and plant response of tolerant and susceptible tropical rice ( Oryza sativa L.) and subtropical wheat ( Triticum aestivum L.) cultivars were compared under vegetative and reproductive stage drought in pot experiments. Water was withheld during reproductive stage until plant available soil moisture content was 30 % of field capacity (FC) or leaf wilting was observed, and then reapplied. Rice reached 30 % FC 9 days after withholding water and wheat after 13 days. Before rewatering, both species reached leaf water potentials of −12 bars and similarly low transpiration rates. Stress reduced leaf relative water content, leaf elongation and membrane stability. When water stress was imposed during reproductive stage, pollen fertility was most affected in wheat, while panicle exsertion and anther dehiscence were severely affected in rice. When water stress was imposed during vegetative stage, wheat was less affected to vegetative stage drought than rice. The nature of differences between tolerant and susceptible cultivars was similar for the two species. However, the differential growth habitats and growth rate of plants needs to be considered in these kinds of experiments.