低温下水杨酸对粳型巨胚稻幼苗生长的影响

本文以粳型巨胚稻西巨胚1号为试验材料,研究了6℃低温处理前用0．25mmol．L-1和0．5mmol．L-1水杨酸进行预处理（叶面喷施和灌根处理）对幼苗生长的影响。结果表明,水杨酸预处理可使巨胚稻幼苗叶片在低温处理下叶绿素和可溶性糖含量增加,提高幼苗的抗寒性,减轻低温伤害,对幼苗地上部分和根系生长具有一定的促进作用。从对提高巨胚稻幼苗抗寒性的效果来看,0．5mmol．L-1浓度水杨酸处理效果较0．5mmol．L-1浓度好,灌根处理效果较叶面喷施好。     

Production of bacterial blight resistant lines from somatic hybridization between Oryza sativa L. and Oryza meyeriana L

Novel bacterial blight (BB) resistance gene(s) for rice was (were) introduced into a cultivated japonica rice variety Oryza sativa (cv. 8411), via somatic hybridization using the wild rice Oryza meyeriana as the donor of the resistance gene(s). Twenty-nine progenies of somatically hybridized plants were obtained. Seven somatically hybridized plants and their parents were used for AFLP (amplified fragment length polymorphism) analysis using 8 primer pairs. Results confirmed that these plants were somatic hybrids containing the characteristic bands of both parents. The morphology of the regenerated rice showed characters of both O.sativa and O.meyeriana. Two somatic hybrids showed highest BB resistance and the other 8 plants showed moderate resistance. The new germplasms with highest resistance have been used in the rice breeding program for the improvement of bacterial blight resistance.     

Obtaining transgenic rice resistant to rice fungal blast disease by controlled cell death strategy

The strategy of the two-component system,composed of Barnase and Barstar which encode RNase and a specific inhibitor to the RNase respectively, is adopted to obtain transgenic rice resistant to rice fungal blast disease. In this study, two chimeric promoters, induced by rice blast fungus pathogen (Magnaporthe grisea), are fused with Barnase respectively to construct two plant expression vectors, pWBNBS and pPBNBS together with the Barstar driven by CaMV 35S promoter. The resistance of the transgenic rice lines to rice blast fungus disease and rice blight disease are evaluated. The results show that (1) the expression of Barnase is induced in rice leaves when inoculated with the spores of Magnaporthe grisea; (2) the induced expression level of Barnase surpasses the level of Barstar, which elicits a similar hypersensitive response (HR) in the leaves, and the transgenic plant shows high resistance to the rice fungal blast disease; and (3) transgenic rice plants also show obvious resistance to rice bacterial blight disease. Taken together, these results suggest that the transgenic rice plants harboring this two-component system acquire relatively broad spectrum resistance against pathogens, especially high resistance to rice fungal pathogen.     

外源胁迫对水稻内源茉莉酸和水杨酸的影响

茉莉酸和水杨酸是植物防御反应中的重要分子，为研究茉莉酸和水杨酸在水稻防御反应中的作用，采用了色谱法测定了此两种激素在外源植物生长调节剂胁迫下的水平变化。我们采用的此方法简单，灵敏度高，再现性好，此两种激素含量变化可得到准确分离与测定。我们的结果表明在水稻中茉莉酸和水杨酸的作用可能不同与其它植物。首先，水杨酸含量变化较缓慢，其次，茉莉酸含量变化较明显。此结果表明水稻中茉莉酸和水杨酸的作用可能不同与烟草和拟南介，在信号传递过程中可能起到正面的调节作用。     

水杨酸对NaCl胁迫下黄芩幼苗生长的影响

温室条件下研究NaCl(0·5%)胁迫和外施不同浓度的水杨酸(salicylicacid,SA)对黄芩幼苗生理活动的影响.NaCl胁迫处理的幼苗与未经过NaCl胁迫处理相比,叶绿素a、叶绿素b含量明显下降,SOD、POD、CAT活性上升后急速下降,引起H2O2和MDA含量显著增加;外施不同浓度的SA和0·5%NaCl共同处理的黄芩幼苗与NaCl胁迫处理相比,叶绿素a、叶绿素b都有不同程度增加,H2O2和MDA含量则有不同程度降低,SOD、CAT活性上升,POD活性显著上升.其中S2,S3在提高NaCl胁迫抗性时效果最佳.以上结果表明适当浓度SA对黄芩幼苗生理活性有一定的改善,增强了植株对盐胁迫的抗性.     

转基因水稻对赤霉素敏感性的初步研究

以水稻品种中花11及其转基因株系为材料,研究它们在苗期对GA3的反应程度.结果表明:用100mg/L的GA3在二叶期对各植株进行喷雾,5d后各个株系苗高都比以喷水的对照组显著增长.在充分考虑起始株高和试验期间对照正常生长动态变化的基础上提出了比净伸长率(specificnetelongateratio,GA3处理的净伸长率和对照净伸长率之比)的概念,并建议根据比净伸长率分析各株系对GA3的敏感性.应用该方法发现2份对GA3钝感的材料.文章报道这一结果并探讨了造成用比净伸长率与常用的“株高增长率”分析水稻品种/株系对GA3敏感性差异的原因.     

PP333对水稻幼苗的生长_叶片结构和抗冷性的影响

用PP333处理水稻幼苗,可改善秧苗素质,例如秧苗矮壮,假茎宽,叶鞘细胞短宽,叶片增厚,叶肉细胞变大,叶脉增粗,叶绿素含量高,发根力强,抗冷性也有所提高.同时,在密播多肥条件下,经过PP333处理,秧苗仍粗壮,故可节约秧地.     

杂交早稻新组合马协118—2应用价值的研究

马协１１８－２经２年省 区试的结果表明,比对照组合汕优７０２３（ＣＫ１）全生育期早２．４ｄ比鄂早６号（ＣＫ２）迟１．７ｄ,产量比ＣＫ１与ＣＫ２分别增产８．６％和７．４％,呈极显著水平;多点试种比鄂早６号增产１０．０％以上,稻米品质为二级食用优质籼米。对白叶枯病,稻瘟病的抗性以及对纹枯病的耐性明显地优于对照。该组合是一个综合性状优良的杂交早稻组合,可在我省及长江中下游地区作迟熟早稻种植。     

Tagging major quantitative trait loci for sheath blight resistance in a rice variety, Jasmine 85

This study was conducted with a clonal F₂ population of rice from a cross between Jasmine 85, a resistant variety, and Lemont, a susceptible cultivar. The rice plants belonging to each F₂ clone were divided into two plots, which were put in two replicates, respectively. Clonal parents were tested as controls. The plants were inoculated by short toothpicks incubated with RH-9, a virulent isolate of the pathogenic fungus,Rhizoctonia solani, which causes rice sheath blight. The extreme resistant and susceptible clonal lines were selected for construction of resistant and susceptible DNA pools, respectively. A total of 94 polymorphic markers evenly distributed on 12 rice chromosomes were used for bulked segregant analysis, three positive ones were found polymorphic between the two DNA pools, and three major QTLs for sheath blight resistance, Rh-2, Rh-3 and Rh-7, were identified. The three major QTLs were located on chromosomes 2, 3 and 7, and could explain 14.4%, 26.1% and 22.2% of the phenotypic variation.     

水分胁迫对水、旱稻幼苗POD活性的影响

以四种抗旱性不同的水、旱稻幼苗为材料,采用愈创木酚分光光度法测定了不同生长时期、水分胁迫以及水分胁迫处理后复水幼苗的POD活性,并与同样条件下水、早稻幼苗SOD活性变化进行比较。结果表明,不仅水、旱稻幼苗SOD活性在不同发育时期、不同水分条件发生有特定规律的变化,而且POD活性也具有类似或同步的变化,即抗旱性较强的旱稻品种在水分胁迫时POD活性上升幅度大于水稻,复水后旱稻POD活性下降的幅度也比水稻大.由于SOD和POD在生化功能上具有偶联作用以及实验结果的相似性.故可以认为,不同水分条件水、旱稻幼苗POD活性的变化和SOD一样能够反映品种间抗旱能力的差异.     

外源水杨酸对甘蓝生理指标的影响

研究了不同浓度的水杨酸(SA)对甘蓝幼苗光合指标和净光合速率日变化.结果表明:随着SA浓度的增加,自由水/束缚水比率逐渐下降,同时用0 01mg·L-1的SA处理后甘蓝幼苗的地上部分和根的干质量和鲜质量都会增加,但是随着SA浓度的增大,其增加量逐渐变小.当甘蓝幼苗经过0 01mg·L-1的SA处理后,叶片的总叶绿素、叶绿素a、叶绿素b的含量分别增长61 9%,75 7%,30 1%.低浓度的SA处理能降低植株的二氧化碳补偿点和光呼吸强度,而使光补偿点和光饱和点上升.不同浓度SA处理的甘蓝幼苗的净光合速率日变化特征与对照的基本一致,差异只在数值大小不同.     

河北省地方水(陆)稻品种抗性的研究

鉴定了近３００ 份河北省地方水（陆）稻品种抗“三逆两病两虫”的情况。结果表明,河北省水（陆）稻品种的耐寒性和耐旱性种质频率高、强度大,耐性种质占８５．６０％ 和４８．６２％ ,高耐种质占２０．１６％ 和１５．５２％ ;抗稻瘟病和白叶枯病种质频率较高,为４５．８６％ 和５０．３４％ ,但高抗种质仅为０．３４％ 和１．０３％ ;耐盐性、抗褐稻虱和白背飞虱种质频率较低,为６．４６％ 、４．５１％ 和３．３４％ ,且抗性强度低。耐寒性种质频率水稻高于陆稻,随纬度增加、经度西移及温热条件降低而增加;耐旱性种质频率陆稻高于水稻,河北省东北地区高,西北及冀中库淀地区低;抗稻瘟病种质频率和强度陆稻均高于水稻,冀东集中种植亚区（唐山、秦皇岛两市）抗性种质丰富,强度高;抗白叶枯病种质频率和强度陆稻均高于水稻,随纬度的增加、生产期的缩短、海拔高度的增高及温热条件的降低,抗性频率和强度呈递减趋势。     

Transfer of bacterial blight resistance from <Emphasis Type="Italic">Oryza meyeriana</Emphasis> to <Emphasis Type="Italic">O. sativa</Emphasis> L. by asymmetric somatic hybridization

Asymmetric somatic hybrid plants were produced between cultivated rice (Oryza sativa L.) and wild species [O. meyeriana (Zoll. etMor, exSteud.)] with high resistance to rice bacterial blight. X-ray-irradiated protoplasts of the wild species were used as donor and chemically fused with iodoacetamide-inactivated protoplasts of rice cv. 02428 to produce hybrids. Seventy-two plants were regenerated from 623 calli based on metabolic complementation. The morphological characters of the plants closely resembled that of the rice. Simple sequence repeats were employed to identify their hybridity. Cytological analysis of root-tips revealed that their chromosome number varied in the range of 27--38. The somatic hybrids were inoculated with strains of Xanthamonas oryzae pv. oryzae at adult growth stage and demonstrated the resistance to bacterial blight introgression from the O. meyeriana.     

水稻纹枯病菌人工接种方法的研究

对水稻纹枯病菌(Rhizoctonia solani AGI-IA)7种人工接种方法进行试验，首次评价了各自优缺点．结果认为：“稻秆离体接种法”是比较理想的人工方法，其特点是快速、简便、发病速度适中、病情调查方便，病原菌容易控制．其次是盆栽苗接种法、叶片离体接种法，菌丝悬浮液较差。     

野栽杂交花培育种探讨

采用花药培养技术对普通野生稻白叶枯病广谱抗源RBB16与水稻品种垦系3号等一批杂交后代进行花培育种。接种花药79080个,平均愈伤组织诱导率7.94％,绿苗分化率15.08％,从获得一批野栽杂交后代的花培绿苗中选育出T209-1、14-5两个高产、或高抗白叶枯病的稳定新品系。研究表明野栽杂交花培育种技术是克服野栽杂交后代稳定难,育种周期长与加速野生稻资源利用的有效途径。     

短日照处理诱导油松容器苗针叶差异表达蛋白质的功能分析

【目的】基于蛋白质水平探讨短日照处理调控油松(Pinus tabulaeformis)容器苗基础代谢和抗逆性机理的研究,完善油松容器苗的育苗和造林技术,为短日照处理育苗技术在我国北方地区困难立地造林中推广应用提供理论依据。【方法】以经日照长度为10 h、持续3 周短日照处理的油松容器苗针叶为研究对象,采用改良的酚法提取针叶蛋白。应用双向电泳结合二级质谱分析的蛋白质组学技术,研究短日照处理诱导油松容器苗针叶蛋白质表达的变化,分析差异表达蛋白质的鉴定和功能。【结果】成功获取5个短日照处理诱导表达差异显著的蛋白质,上调表达的是叶绿体放氧增强蛋白1(oxygen-evolving enhancer protein 1, OEE1)(蛋白点404)、甘油醛-3-磷酸脱氢酶(glyceraldehyde-3-phosphate dehydrogenase, GAPDH)(蛋白点539)、延伸因子-Tu(elongation factor-Tu, EF-Tu)(蛋白点654)、核酮糖-1,5-二磷酸羧化酶/加氧酶活化酶(ribulose bisphosphate carboxylase/oxygenase activase, RCA)(蛋白点681); 下调表达的是磷酸甘油酸激酶1(phosphoglycerate kinase 1, PGK1)(蛋白点641)。这些蛋白质的功能主要涉及光合代谢、糖代谢和胁迫防御。【结论】短日照处理诱导油松容器苗蛋白质差异表达,对油松容器苗的基础代谢和抗逆性产生重要影响。     

稻白叶枯菌弱毒株诱导的系统抗性——兼论与防御酶活性的变化

2 个品种(余水糯, 浙辐802)的水稻幼苗经白叶枯菌( Xanthomonas oryzae pv. oryzae) 弱毒株75-1处理后,均获得了对白叶枯菌强毒株 76-25 的系统抗性,超氧化物歧化酶( SOD) 、 过氧化氢酶( CAT) 活性下降, 脂氧合酶( LOX)、 丙二醛含量升高Ti ron 削弱了75- 1对上述指标的诱导作用,导致75-1对余水糯和浙福 802 的互作由非亲和性类型转变为类似亲和性性类型.提示 O^{- .}₂ 等活性氧介导的脂膜过氧化损伤及防御酶系统的活性变化与水稻幼苗对稻白叶枯病的系统性抗性有关.     

杂交早稻新组合汕优242应用价值的研究

3年研究结果表明,汕优242比当前生产上推广组合威优49早热2d,两者产量水平相当,汕优242稻米品质为二级籼米,3个主要米质指标均优于威优49;对白叶枯病和稻瘟病的抗性及苗期抗寒性也明显优于威优49。该组合适合在我省作中迟熟早稻种植。     

Involvement of Jasmonate-signaling pathway in the herbivore-induced rice plant defense

The expression patterns of eight defense- related genes in the herbivore-infested and jasmonate- treated (jasmonic acid, JA and its derivative MeJA) rice leaves were analyzed using RT-PCR. The results showed that Spodoptera litura Fabricius (Lepidoptera: Noctuidae) herbi-vory induced the expression of lipoxygenase (LOX) and al-lene oxide synthase (AOS) genes that are involved in the jasmonate-signaling pathway. Moreover, S. litura damage resulted in the expression of farnesyl pyrophosphate syn-thase (FPS), Bowman-birk proteinase inhibitor (BBPI), phenylalanine ammonia-lyase (PAL) and other rice defense- related genes that were also induced by aqueous JA treat-ment or gaseous MeJA treatment. These indicated that in rice leaves, the JA-related signaling pathway was involved in the S. litura-induced chemical defense. Mechanical damage and brown planthopper (BPH), Nilaparvata lugens (St錶) (Homoptera: Delphacidae) damage induced the expression of LOX gene, but both treatments did not induce the expression of AOS gene. However, BPH damage induced the expression of acidic pathogen-related protein 1 (PR-1a), Chitinase (PR-3), and PAL genes, which is involved in the salicylate- signaling pathway. It was suggested that salicylate-related signaling pathway or other pathways, rather than jas-monate-signaling pathway was involved in the BPH-induced rice plant defense.