广东雷州杂草稻黑壳基因Bh4和红皮基因Rc的基因型鉴定

为测定雷州杂草稻的黑色颖壳基因Bh4和红色果皮基因Rc的基因型,本研究对雷州10个杂草稻群体的100个单株的种子的颖壳和果皮颜色进行表型观察,同时通过PCR扩增及序列分析对Bh4和Rc的基因型进行鉴定。结果表明,雷州杂草稻中黑色颖壳和黄色颖壳的种子几乎各占一半,果皮颜色则以红色为主,有少量白色和浅红色果皮的种子。雷州杂草稻的Bh4和Rc的基因型与表型鉴定结果一致。57份黑色颖壳杂草稻的Bh4基因型为39个野生型和18个杂合型,25份黄色颖壳和18份黄色带黑斑颖壳杂草稻的Bh4基因型均为缺失22 bp的突变型;90份红色果皮杂草稻的Rc基因型为73个野生型和17个杂合型,4份白色和6份浅红色果皮杂草稻的Rc基因型均为缺失14 bp的突变型。本研究为分析雷州杂草稻的Bh4和Rc基因的来源提供了分子基础。     

江苏省杂草稻的传播与籼粳分化研究

21世纪初,杂草稻仅在江苏省局部区域发生,目前已扩大到全省,并对粳稻的高产和稳产造成严重威胁。为了掌握其快速发生机制,便于杂草稻的防除工作,需要进一步明确江苏省13市杂草稻是独立发生还是相互传播,以及江苏省杂草稻籼粳地理分布。采集了江苏省13个市58个样地的58个种群,总计205份的杂草稻样品。所有样品在南京农业大学江浦农场田间种植,并测量了38个形态学性状和6个程氏指数鉴别性状。欧氏距离聚类分析,表明江苏省13个市的杂草稻是相互混杂的。籼粳地理分布表明,江苏省杂草稻主要以籼型和偏籼型为主,籼型和偏籼型杂草稻在全部58个样点中都有分布,分别占样品总量的54.15%和42.40%;偏粳型和粳型仅分布于6个样点(淮安、苏州、盐城与扬州),分别占样品总量的2.93%和0.48%。此外,对比江苏省杂草稻的籼粳地理分布与江苏省地方品种的籼粳地理分布,未显示对应关系。籼粳比例和地理分布揭示了江苏省杂草稻主要为籼型,其中极少数为粳型杂草稻,粳型杂草稻的比例与杂草稻和栽培稻之间的自然基因漂移比例相近。     

丹东杂草稻与栽培稻的稻米品质分析比较

以2个丹东杂草稻材料、3个常规粳稻品种、3个常规籼稻品种、3个杂交稻品种等4种类型的水稻为实验材料,从米质常规12项、14种微量元素的含量以及16种氨基酸含量等方面进行米质分析。米质常规12项结果显示,杂草稻的整精米率和蛋白质含量在4种类型的水稻中最高,分别达到65.8%和10.6%,但与其他3类水稻的差异程度没有达到显著水平;糙米率和精米率与籼型稻相近;长宽比和粒长介于籼型常规水稻与粳型常规水稻之间;垩白粒率和垩白度在4种类型水稻中最高,分别达到55.5%和8.2%,但与其他3种类型水稻相比,差异不显著。对14种微量元素的分析结果显示,杂草稻的钙、镁、铁、铜、锌、硒、钠、铬等8种微量元素含量在4种类型水稻中均最高,其中硒含量达到0.045 mg/kg,是常规籼稻的2倍、常规粳稻的3倍多和杂交稻的6倍多,差异均达到显著水平;而汞、铅、镉、砷等有毒重金属含量在4种类型水稻中最低或没有检测出来。而对16种氨基酸的检测结果显示,4种类型水稻16种氨基酸含量差别不大,没有显著差异;但杂草稻组氨酸的含量比其他3种类型水稻组氨酸含量高近1倍,达到0.58 g/100 g。实验鉴定显示,杂草稻品种DDC-08-D4-na达到三等食用籼稻标准,杂草稻品种DDC-08-D4-la达到四等食用籼稻标准。对杂草稻的米质进行全面分析,结果显示杂草稻不仅在氨基酸含量上与其他3种类型的水稻品种相近,而且在整精米率和蛋白质含量上要好于其他3种类型的水稻品种,在多种微量元素含量方面也要高于其他3种类型的水稻品种,其中以硒的含量最为突出,说明杂草稻在米质上具有开发利用潜力。     

杂草稻遗传多样性评价与分析

对从韩国引进、收集于亚洲不同产稻国的杂草稻材料,田间隔离种植、观察、记载杂草稻农艺性状和经济性状,分析其遗传多样性。结果表明,参试的199份杂草稻中,杂草稻抽穗天数和株高的变化范围均大于栽培稻;颖壳色共6种,多数表现为淡黄色和黄褐色斑点、微红、金色（似栽培稻颖色）,部分表现黑褐色和褐色（似野生稻颖色）;种皮色以红色为主,部分为白色;40．7％材料有芒,芒色以金色和紫色为主;部分材料易落粒;再生力强。结果表明：不同生态型杂草稻的生物学特性差异较大,变异类型丰富,是水稻遗传改良的重要资源,在水稻改良中应有目的地选择利用。     

广东雷州杂草稻sh4和qSH1基因的功能SNP位点序列分析

sh4和qSH1基因是水稻的主效落粒基因,本研究旨在测定雷州杂草稻的sh4和qSH1的基因型,为雷州杂草稻的落粒机制研究提供分子基础。本研究从雷州10个杂草稻群体采集了100个单株及10份栽培稻种子,观测其颖壳颜色、果皮颜色和芒及落粒率,并对sh4和qSH1的功能SNP位点进行PCR扩增及序列分析。结果表明,57份杂草稻的sh4功能SNP位点为野生落粒型（G）,15份为杂合型G/T,28份为突变难落粒型（T）。其中,G型和G/T型的72份杂草稻的落粒率都极高（95%~100%）,而28份T型杂草稻中,19份为中度落粒（30%~75%）,5份杂草稻的落粒率很高（>95%）,4份杂草稻的落粒率小于30%。100份杂草稻和10份栽培稻的qSH1功能SNP位点均为G。结合落粒表型及基因型,推测sh4是调控雷州杂草稻落粒性的一个主要基因。     

盐城市稻田杂草稻防治措施

盐城市是江苏省农业大市,常年水稻种植面积30万hm2,近几年来,免耕直播稻成为江苏省农业重点推广技术,该项技术因能减少劳力和避开灰飞虱危害高峰期而被逐渐采用.2008年盐城市直播水稻面积近20万hm2,然而伴随直播稻的增加,杂草稻也变成为一个棘手的问题,发生蔓延逐年加重,范围越来越广,因该稻种皮为红色而被农民称为红米稻, 红米杂草稻不仅产量低、米质差,且与正常稻株争光、争肥、争生长空间,严重影响栽培水稻的正常生长,这种稻由于其产量、稻米品质等系列缺陷而成为恶性杂草,已成为水稻生产一大公害.     

利用CRISPR/Cas9技术创制Rc基因恢复红稻

【目的】将栽培稻品种恢复为米质优、抗逆性强的红稻具有较大的研究价值。利用CRISPR/Cas9基因编辑技术,编辑原花青素转录调节因子Rc基因,恢复红种皮特性,以改良水稻米质,提升抗逆性。【方法】利用CRISPR/Cas9技术,以Rc为靶基因,构建突变载体p YLCRISPR/Cas9-Rc-g RNA,以空育180、上育453为材料,转化获得转基因植株,通过测序手段和表型观察验证成果。【结果】分子水平检测获得Rc突变材料2种,其中KY-1在1414―1417bp缺失4个碱基,终止子突变为苯丙氨酸;SY-1在1411bp处缺失1个碱基,终止子突变为天冬氨酸。2种编辑材料均恢复为红米表型,且具有一定耐盐碱能力。【结论】利用CRISPR/Cas9基因编辑技术成功获得恢复红种皮表型的纯合株系,为红米改良提供基础材料。     

杂草稻与栽培稻对氮素营养竞争的初步研究

以沈农265与杂草稻WR03-12为实验材料,采用盆栽替代法研究杂草稻与栽培稻灌浆期不同器官的氮素含量及积累量的变化。盆栽模拟试验证明,在同一时期栽培稻各器官的含氮量和氮素积累量随着杂草稻插入比例的增加而逐渐降低,其中栽培稻根部受影响最为显著。对不同处理产量进行方差分析表明,栽培稻单株产量随杂草稻插入比例的增加明显下降,处理间皆达到极显著水平。杂草稻单株穗数、穗粒数和单株产量受种植比例影响均极显著。     

杂草稻资源表型多样性分析及综合评价研究

杂草稻是生长形态与栽培稻相似,而稻米质量、落粒性和休眠性等性状不符合栽培稻生产需求的一类杂草。江苏省是我国杂草稻危害最严重的省份之一,大量研究主要集中在杂草稻的起源、性状和防控,杂草稻群体作为种质资源用于栽培稻品种改良尚无系统研究。丰富的遗传多样性和优良种质资源是栽培稻育种以及品种改良中最重要的物质基础,本研究收集21个江苏省不同地区的杂草稻群体、6个栽培稻品种和2个杂草稻对照群体为材料,通过在海南同质园种植,测定18个表型性状,分析其性状的多样性,并进行相关性分析、主成分分析、聚类分析和综合评价研究。结果表明：杂草稻的齐穗期和齐花期均明显早于栽培稻,杂草稻的实粒数和总粒数均较优于栽培稻,杂草稻资源群体表型性状变异系数为2.99%~196.29%,多样性指数为0.27~2.06,多样性指数最高的是结实率,其次为实粒数、剑叶长/宽和总粒数。相关性分析表明,18个表型性状之间大部分存在显著或极显著相关,始穗期和始花期与株高、穗长、剑叶长宽比、总粒数、实粒数、千粒重、分蘖数间均呈极显著正相关,千粒重与穗长、剑叶长宽比、分蘖数、始穗期、始花期呈极显著正相关。主成分分析将18个表型性状集中在累计贡献率为70.57%的6个主成份,其中正相关影响最大的性状是杂草稻的始穗期、始花期、齐穗期、齐花期、总粒数、实粒数等性状。聚类分析将23个杂草稻群体在欧式距离为5时分为5大类。18个指标综合评价D值>0.68的有3个群体,其中,来自南通如皋WJ-NJ1的D值最高（0.715）,其次是来自常州金坛WJ-CZ1（0.698）和盐城市辖区WJ-YC2（0.682）。本研究为杂草稻种质资源在未来的辅助育种以及栽培稻品种改良等方面提供了重要的理论依据。     

辽宁杂草稻雌蕊性状的初步研究

以辽宁省杂草稻与栽培稻为试验材料,对柱头外露率、柱头表面积、柱头活力3个雌蕊的性状进行了比较研究。结果表明,参试杂草稻在柱头外露率指标上具有较大的变异幅度,其变幅分别为7．6％～59．3％。以柱头外露率为指标进行UPGMA聚类分析,结果显示,所有参试材料可被分为两大类,籼稻与粳稻分别被划分在这两大类之中,杂草稻虽无独立类群的划分,但不同编号材料均表现出向某一类分化的趋势。所有参试材料柱头表面积都因品种的不同而具有相对独立的特点,并不具有明显的分类特征表现。参试杂草稻柱头活力低于参试栽培稻品种。     

Allele Types of Rc Gene of Weedy Rice from Jiangsu Province,China

Weedy rice(Oryza sativa f. spontanea), the predominant type of which has a red pericarp, seriously inhibits growth and yield of direct-seeded rice in Jiangsu Province, China. In this study, we randomly selected 10 weedy rice accessions from 10 plots in Jiangsu, and then sequenced the full lengths of their Rc genes(approximately 6.4 kb). In addition, we collected 166 different full-length Rc genes in the Oryza genus from the literature and from GenBank. A collinearity sequence analysis showed that the 10 weedy rice accessions from Jiangsu all had the same wild-type allele of the Rc gene. Single nucleotide polymorphisms indicated that the nucleotide polymorphisms(π = 0.19) and the proportion of segregation sites(θw = 0.28) of the Rc genes in the 10 weedy rice accessions from Jiangsu were higher than those in 56 weedy rice accessions from USA(π = 0.09 and θw = 0.07). Haplotype and phylogenetic analyses showed that the Rc genes of weedy rice accessions from Jiangsu were not revertants of the rc gene found in Asian cultivated rice(O. sativa) varieties with white pericarp. In addition, Rc gene sequences of the rice varieties Lvdao from Lianyungang, Jiangsu and Tangdao from Anhui were more similar to those of cultivated rice than to the weedy rice from Jiangsu. These findings support the continued quarantine of weedy rice and clarify the evolutionary mechanism of the red pericarp found in the weedy rice of Jiangsu.     

Genetic Diversity and Relationship of Weedy Rice in Taizhou City, Jiangsu Province, China

Microsatellite markers and morphological charactedstics were used to explore the genetic diversity and possible origin of weedy dce in Taizhou City, Jiangsu Province, China. Fifty-two weedy rice (Oryza sativa L.) accessions were compared with two wild rice, four hybdd rice and five cultivars using 22 simple sequence repeat (SSR) primer pairs. A total of 107 fragments were amplified, averaging 5.6 alleles per primer pair. The polymorphic index content (PIC) values ranged from 0.3077 to 0.7951, averaging at 0.5870. The average genetic distance of all samples ranged from 0.02 to 0.46 with an average of 0.262. The genetic distance among Taizhou weedy rice ranged from 0.03 to 0.44 with an average of 0.224. Cluster analysis showed that all the weedy rice accessions from Taizhou City were indica, and could be subdivided into different genotypes. The majority (86%) of weedy rice was most closely related to hybrid rice. The Taizhou weedy dce accessions were morphologically similar, but still could be delineated into indica or japonica group by some morphological traits. it is suggested that the levels of genetic and morphological diversities of weedy rice in Taizhou City are low and these weedy rice plants originated from the segregating progenies of hybrid rice that had naturally introgressed with cultivated rice.     

干旱胁迫下杂草稻和栽培稻根系基因表达差异研究

利用Affymetrix水稻表达谱芯片(GeneChip Rice Genome Array)研究抗旱杂草稻HEB07-2与巴西陆稻(IAPAR9)在PEG模拟干旱胁迫下根系基因表达变化。结果表明,杂草稻HEB07-2转录组对干旱信号的响应程度与方向均与巴西陆稻存在很大差异,HEB07-2以正向调控为主,而巴西陆稻以负调控为主。干旱胁迫下杂草稻HEB07-2与巴西陆稻分别有6878个和2923个基因表达,其中HEB07-2受干旱胁迫诱导上调的基因有4693个,下调的基因有2185个;而巴西陆稻则分别有983个和1940个。在差异基因表达的倍数上也是HEB07-2高于巴西陆稻。进一步的GO分析表明,在干旱胁迫下,HEB07-2和IAPAR9根系基因响应途径的差异表现为HEB07-2在钾离子转运(GO:0006813)、次生物质代谢(GO:0019748)、细胞生长(GO:0016049)、葡萄糖代谢(GO:0006006)、跨膜离子转运器活性(GO:0015075)、亚铁血红素结合体(GO:0020037)、氧化还原酶活性(GO:0016491)等方面基因显著上调,这与生理数据和表型数据一致。     

Transgene Flow from Glufosinate-Resistant Rice to Improved and Weedy Rice in China

The development of transgenic rice with novel traits in China can increase rice productivity, but transgene flow to improved or weedy rice has become a major concern. We aimed to evaluate the potential maximum frequencies of transgene flow from glufosinate-resistant rice to improved rice cultivars and weedy rice. Treatments were arranged in randomized complete blocks with three replicates. Experiments were conducted between 2009 and 2010 at the Center for Environmental Safety Supervision and Inspection for Genetically Modified Plants, China National Rice Research Institute, Hangzhou, China. Glufosinate-resistant japonica rice 99-1 was the pollen donor. The pollen recipients were two inbred japonica rice （Chunjiang 016 and Xiushui 09）, two inbred indica rice （Zhongzu 14 and Zhongzao 22）, two indica hybrid rice （Zhongzheyou 1 and Guodao 1）, and one weedy indica rice （Taizhou weedy rice）. The offspring of recipients were planted in the field and sprayed with a commercial dose of glufosinate. Leaf tissues of survivors were analyzed by polymerase chain reaction to detect the presence of the transgene. The frequency of gene flow ranged from 0 to 0.488%. In 2009, the order of gene flow frequency was as follows： weedy rice 〉 Chunjiang 016 〉 Xiushui 09 and Zhongzu 14 〉 Guodao 1, Zhongzheyou 1 and Zhongzao 22. Gene flow frequencies were generally higher in 2009 than in 2010, but did not differ significantly among rice materials. Gene flow frequency was the highest in weedy rice followed by the inbred japonica rice. The risk of gene flow differed significantly between years and year-to-year variance could mask risk differences among pollen recipients. Gene flow was generally lesser in taller pollen recipients than in shorter ones, but plant height only accounted for about 30% of variation in gene flow. When flowering synchrony was maximized, as in this study, low frequencies of gene flow occurred from herbicide-resistant japonica rice to other cultivars and weedy rice. Averaged across years, the risk     

利用SRAP分子标记分析47份杂草稻样品遗传多样性

 利用SRAP分子标记分析了采集于杂草稻多发地区的47份样本的遗传多样性,旨在从基因的开放式阅读框区域（ORFs）深入研究杂草稻的遗传背景,为进一步揭示其来源提供依据。结果表明,参试的我国杂草稻材料在110对引物组合中共扩增出845种类型的谱带,多态性谱带590种,多态率为6982%,平均每对引物可以检测到54条多态性谱带。说明SRAP分子标记对于杂草稻基因组开放式阅读框区域序列的多态性具有很高的检测效率,适用于遗传多样性研究。我国杂草稻材料Shannon Weaver多样性指数（I）为063,且南北方杂草稻多样性指数（I）相当,分别为063和062。聚类分析结果表明,南方收集的杂草稻与北方收集杂草稻群体间遗传分化较大,遗传差异明显。程氏指数判定结果也表明杂草稻呈南籼北粳的分布状态。     

杂草稻和栽培稻叶片下表皮结构特征的观察及聚类分析

 利用光学显微镜对33份杂草稻及6份栽培稻材料的叶片下表皮中央长细胞及其各级乳突、气孔器及其乳突的结构特征进行了观察、统计后作主成分分析及聚类分析。主成分分析后得到3个在各个性状因子中贡献率最大的主成分,分别是中央长细胞大乳突、中乳突及小乳突的数目、大小,气孔密度。叶表皮结构特征在各供试材料之间有一定的变异和特异性,在杂草稻分类鉴定及亲缘关系的研究中具有一定的价值。